Integrated Taxonomic Information System - Search Results

Results of: Search in every Kingdom for Taxon Author(s) Name(s) L. OR L 'L.'
 
 Kingdom Chromista
  Leathesia difformis L. – accepted
 
 Kingdom Plantae
  Abrus precatorius L. – accepted – rosarypea, crab's eye, jequerity, pois rouge, precatory bean, rosary pea, tento muido
  Acalypha L. – accepted – copperleaf
  Acalypha australis L. – accepted – Australian acalypha, Asian copperleaf
  Acalypha indica L. – accepted – Indian copperleaf
  Acalypha virginica L. – accepted – Virginia copperleaf, mercuryweed, threeseeded mercury, wax balls, Virginia threeseed mercury
  Acalypha virginica var. virginica L. – not accepted – Virginia threeseed mercury
  Acanthus L. – accepted
  Acanthus mollis L. – accepted – bear's breech
  Acanthus spinosus L. – accepted – spine acanthus
  Acer L. – accepted – maples
  Acer campestre L. – accepted – field maple, hedge maple
  Acer negundo L. – accepted – ashleaf maple, boxelder, boxelder maple, California boxelder, Manitoba maple, western boxelder, box elder, three-leaf maple, ash-leaf maple
  Acer negundo var. negundo L. – accepted – ash-leaf maple, boxelder
  Acer pensylvanicum L. – accepted – moosewood, striped maple
  Acer platanoides L. – accepted – Norway maple
  Acer pseudoplatanus L. – accepted – sycamore, sycamore maple
  Acer rubrum L. – accepted – red maple
  Acer rubrum var. rubrum L. – accepted – red maple
  Acer saccharinum L. – accepted – silver maple
  Acer tataricum L. – accepted – Tatarian maple
  Achillea L. – accepted – yarrow
  Achillea aegyptiaca L. – accepted
  Achillea ageratum L. – accepted – sweet-Nancy, sweet yarrow
  Achillea alpina L. – accepted – Chinese yarrow, Siberian yarrow
  Achillea clavennae L. – accepted
  Achillea impatiens L. – accepted
  Achillea macrophylla L. – accepted
  Achillea millefolium L. – accepted – common yarrow, milenrama, milfoil, western yarrow, bloodwort, carpenter's weed, hierba de las cortaduras, plumajillo, yarrow
  Achillea millefolium var. millefolium L. – not accepted – common yarrow
  Achillea nobilis L. – accepted – noble yarrow
  Achillea odorata L. – accepted
  Achillea ptarmica L. – accepted – sneezeweed
  Achras mammosa L. – not accepted
  Achras zapota L. – not accepted
  Achyranthes L. – accepted – chaff flower
  Achyranthes aspera L. – accepted – devil's horsewhip
  Achyranthes aspera var. aspera L. – accepted – devil's horsewhip
  Achyranthes aspera var. sicula L. – accepted
  Achyranthes prostrata L. – not accepted
  Achyranthes repens L. – not accepted
  Acnida L. – not accepted
  Acnida cannabina L. – not accepted
  Aconitum L. – accepted – monkshood, aconite, wolfsbane
  Aconitum anthora L. – accepted – yellow monkshood
  Aconitum lycoctonum L. – accepted
  Aconitum napellus L. – accepted – Venus' chariot
  Aconitum uncinatum L. – accepted – southern blue monkshood
  Aconitum uncinatum ssp. uncinatum L. – not accepted – southern blue monkshood
  Aconitum variegatum L. – accepted – Manchurian monkshood
  Acorus L. – accepted – sweetflag, sweet-flag
  Acorus calamus L. – accepted – sweetflag, calamus, sweet-flag
  Acrostichum L. – accepted – leatherfern
  Acrostichum aureum L. – accepted – golden leatherfern
  Acrostichum citrifolium L. – not accepted
  Acrostichum crinitum L. – not accepted
  Acrostichum digitatum L. – not accepted
  Acrostichum polypodioides L. – not accepted
  Acrostichum thalictroides L. – not accepted
  Actaea L. – accepted – baneberry
  Actaea racemosa L. – accepted – black snakeroot, black cohosh, black baneberry
  Actaea racemosa var. racemosa L. – not accepted – black bugbane
  Actaea spicata L. – accepted – baneberry
  Adansonia L. – accepted
  Adansonia digitata L. – accepted – baobab
  Adelia L. – accepted – lime, wild lime
  Adelia bernardia L. – not accepted
  Adelia ricinella L. – accepted – wild lime
  Adenanthera L. – accepted – beadtree
  Adenanthera pavonina L. – accepted – red beadtree, coral bean tree, false wiliwili, lopa, pomea, red bead tree, red sandlewood
  Adiantum L. – accepted – maidenhair fern
  Adiantum capillus-veneris L. – accepted – common maidenhair fern, venus hairfern, common maidenhair
  Adiantum caudatum L. – accepted – tailed maidenhair
  Adiantum clavatum L. – not accepted
  Adiantum cristatum L. – not accepted
  Adiantum pedatum L. – accepted – northern maidenhair, maidenhair fern, maidenhair, maidenfern
  Adiantum philippense L. – not accepted
  Adiantum pulverulentum L. – accepted – glossy maidenhair
  Adiantum trapeziforme L. – accepted – diamond maidenhair
  Adiantum villosum L. – accepted – woolly maidenhair
  Adonis L. – accepted – adonis, pheasant's eye
  Adonis aestivalis L. – accepted – summer pheasant's eye
  Adonis aestivalis L. – not accepted
  Adonis annua L. – accepted – blooddrops
  Adonis autumnalis L. – not accepted
  Adonis vernalis L. – accepted – spring pheasant's eye
  Adoxa L. – accepted
  Adoxa moschatellina L. – accepted – muskroot
  Aegilops L. – accepted – goatgrass
  Aegilops exaltata L. – not accepted
  Aegilops incurva L. – not accepted
  Aegilops incurvata L. – not accepted
  Aegilops squarrosa L. – not accepted
  Aegilops triuncialis L. – accepted – barbed goatgrass, barb goatgrass
  Aeginetia L. – accepted
  Aeginetia indica L. – accepted – ye gu
  Aegopodium L. – accepted – goutweed
  Aegopodium podagraria L. – accepted – bishop's goutweed
  Aeschynomene L. – accepted – jointvetch
  Aeschynomene americana L. – accepted – shyleaf
  Aeschynomene aspera L. – accepted – sola pith plant
  Aeschynomene indica L. – accepted – Indian jointvetch, kat sola, jointvetch
  Aesculus L. – accepted – buckeye, horsechestnut
  Aesculus hippocastanum L. – accepted – horse chestnut
  Aesculus pavia L. – accepted – red buckeye
  Aesculus pavia var. pavia L. – accepted – red buckeye
  Aethusa L. – accepted
  Aethusa cynapium L. – accepted – fool's parsley
  Agave L. – accepted – agave, agave species
  Agave americana L. – accepted – American century plant, American agave, Maguey americano, centuryplant
  Agave americana ssp. americana L. – accepted – American century plant
  Agave americana ssp. americana var. americana L. – not accepted – American century plant
  Agave americana var. americana L. – accepted – American century plant
  Agave virginica L. – not accepted
  Ageratum L. – accepted – whiteweed, ageratum
  Ageratum conyzoides L. – accepted – tropical whiteweed
  Agrimonia L. – accepted – agrimony
  Agrimonia eupatoria L. – accepted – churchsteeples
  Agrimonia repens L. – accepted – creeping grovebur, creeping agrimony
  Agrostemma L. – accepted – corn-cockle, corncockle
  Agrostemma coronaria L. – not accepted
  Agrostemma githago L. – accepted – corncockle, cockle, corn cockle, purple cockle, common corncockle
  Agrostemma githago var. githago L. – accepted – common corncockle
  Agrostis L. – accepted – bentgrass
  Agrostis alba L. – not accepted
  Agrostis alba f. alba L. – not accepted
  Agrostis alba var. alba L. – not accepted
  Agrostis arundinacea L. – not accepted
  Agrostis australis L. – not accepted
  Agrostis calamagrostis L. – not accepted
  Agrostis canina L. – accepted – velvet bentgrass
  Agrostis capillaris L. – accepted – colonial bentgrass, colonial bent
  Agrostis cruciata L. – not accepted
  Agrostis indica L. – not accepted
  Agrostis interrupta L. – not accepted
  Agrostis matrella L. – not accepted
  Agrostis mexicana L. – not accepted
  Agrostis miliacea L. – not accepted
  Agrostis minima L. – not accepted
  Agrostis pumila L. – not accepted
  Agrostis radiata L. – not accepted
  Agrostis rubra L. – not accepted
  Agrostis spica-venti L. – not accepted
  Agrostis stolonifera L. – accepted – creeping bentgrass, carpet bentgrass, spreading bent, creeping bent, redtop, redtop bent, seaside bentgrass
  Agrostis stolonifera ssp. stolonifera L. – not accepted
  Agrostis stolonifera var. stolonifera L. – accepted – creeping bentgrass
  Agrostis virginica L. – not accepted
  Agyneia pubera L. – not accepted
  Aira L. – accepted – hairgrass, European hairgrass
  Aira alpina L. – not accepted
  Aira aquatica L. – not accepted
  Aira caerulea L. – not accepted
  Aira canescens L. – not accepted
  Aira caryophyllea L. – accepted – silver hairgrass
  Aira caryophyllea var. caryophyllea L. – accepted
  Aira cespitosa L. – not accepted
  Aira cristata L. – not accepted
  Aira flexuosa L. – not accepted
  Aira indica L. – not accepted
  Aira montana L. – not accepted
  Aira praecox L. – accepted – yellow hairgrass
  Aira spicata L. – not accepted
  Aira subspicata L. – not accepted
  Ajuga L. – accepted – bugle
  Ajuga genevensis L. – accepted – blue bugle
  Ajuga reptans L. – accepted – common bugle
  Alcea L. – accepted – hollyhock
  Alcea ficifolia L. – not accepted – Antwerp hollyhock
  Alcea rosea L. – accepted – hollyhock, common hollyhock, rose trémière
  Alcemilla L. – not accepted
  Alchemilla L. – accepted – lady's mantle
  Alchemilla alpina L. – accepted – alpine lady's mantle
  Alchemilla vulgaris var. vulagris L. – not accepted
  Aletris L. – accepted – colicroot
  Aletris farinosa L. – accepted – white colicroot
  Alisma L. – accepted – waterplantain, water plantain
  Alisma natans L. – not accepted
  Alisma parnassifolium L. – not accepted
  Alisma plantago-aquatica L. – accepted – American waterplantain, European water plantain
  Alisma plantagoaquatica L. – not accepted
  Alisma ranunculoides L. – not accepted
  Allamanda L. – accepted
  Allamanda cathartica L. – accepted – golden trumpet
  Allionia L. – accepted – windmills
  Allionia incarnata L. – accepted – trailing allionia, trailing four o'clock, trailing windmills
  Allionia incarnata var. incarnata L. – accepted – trailing windmills, crested windmills
  Allionia violacea L. – not accepted
  Allium L. – accepted – oignon, wild onion, onion
  Allium ampeloprasum L. – accepted – broadleaf wild leek
  Allium ampeloprasum var. ampeloprasum L. – not accepted – broadleaf wild leek
  Allium ascalonicum L. – accepted – wild onion
  Allium canadense L. – accepted – meadow onion, ail du Canada, wild onion, Canada garlic, meadow garlic
  Allium canadense var. canadense L. – accepted – meadow garlic, Canada garlic
  Allium carinatum L. – accepted – keeled garlic
  Allium cepa L. – accepted – garden onion
  Allium cepa var. cepa L. – not accepted – garden onion
  Allium fistulosum L. – accepted – welsh onion
  Allium nigrum L. – accepted – black garlic
  Allium odorum L. – accepted – Chinese chives
  Allium oleraceum L. – accepted – field garlic
  Allium paniculatum L. – accepted – Mediterranean onion, wild onion
  Allium paniculatum var. paniculatum L. – accepted – Mediterranean onion
  Allium porrum L. – accepted – garden leek
  Allium ramosum L. – accepted
  Allium rodundum L. – not accepted
  Allium rotundum L. – accepted
  Allium sativum L. – accepted – cultivated garlic
  Allium sativum var. sativum L. – accepted – cultivated garlic
  Allium schoenoprasum L. – accepted – wild chive, wild chives
  Allium schoenoprasum var. schoenoprasum L. – not accepted – wild chives
  Allium scorodoprasum L. – accepted – sand leek
  Allium scorodoprasum L. – not accepted
  Allium sibiricum L. – not accepted
  Allium triquetrum L. – accepted – threecorner leek
  Allium ursinum L. – accepted – bear garlic
  Allium victorialis L. – accepted – victory onion
  Allium vineale L. – accepted – wild garlic
  Allium vineale ssp. vineale L. – not accepted – wild garlic
  Allophylus L. – accepted
  Allophylus zeylanicus L. – accepted
  Aloe L. – accepted – aloes
  Aloe perfoliata L. – accepted – mitra aloe
  Aloe perfoliata var. vera L. – not accepted
  Aloe perfoliata var. vera L. – not accepted
  Aloe variegata L. – not accepted – kanniedood aloe, partridge aloe, partridge breast aloe, tiger aloe, variegated aloe
  Alopecurus L. – accepted – foxtail
  Alopecurus agrestis L. – not accepted
  Alopecurus geniculatus L. – accepted – water foxtail, marsh meadow-foxtail
  Alopecurus geniculatus var. geniculatus L. – accepted – water foxtail
  Alopecurus monspeliensis L. – not accepted
  Alopecurus pratensis L. – accepted – meadow foxtail, field meadow-foxtail
  Alsine media L. – not accepted
  Alstroemeria L. – accepted – lily of the Incas
  Alstroemeria pelegrina L. – accepted
  Althaea L. – accepted – marshmallow, guimauve
  Althaea cannabina L. – accepted – palmleaf marshmallow, hemp-leaved marshmallow
  Althaea hirsuta L. – accepted – hairy marshmallow, rough marshmallow
  Althaea officinalis L. – accepted – common marsh-mallow, common marshmallow, guimauve officinale
  Alyssum L. – accepted – alyssum, madwort
  Alyssum alpestre L. – accepted
  Alyssum calycinum L. – not accepted
  Alyssum incanum L. – not accepted
  Alyssum montanum L. – accepted – mountain madwort
  Alyssum saxatile L. – not accepted
  Amaranthus L. – accepted – pigweed
  Amaranthus albus L. – accepted – pigweed amaranth, white pigweed, pigweed, prostrate pigweed, tumble pigweed, tumbleweed
  Amaranthus blitum L. – accepted – purple amaranth
  Amaranthus blitum var. blitum L. – not accepted – purple amaranth
  Amaranthus caudatus L. – accepted – quelite, love-lies-bleeding
  Amaranthus cruentus L. – accepted – red amaranth
  Amaranthus deflexus L. – accepted – largefruit amaranth
  Amaranthus gangeticus L. – not accepted
  Amaranthus graecizans L. – accepted – Mediterranean amaranth, spreading pigweed, tumbleweed
  Amaranthus hybridus L. – accepted – green pigweed, smooth amaranth, smooth pigweed, slim amaranth
  Amaranthus hypochondriacus L. – accepted – Prince-of-Wales-feather, Prince-of-Wales feather
  Amaranthus lividus L. – not accepted
  Amaranthus paniculatus L. – not accepted
  Amaranthus polygonoides L. – accepted – tropical amaranth
  Amaranthus retroflexus L. – accepted – red-root amaranth, redroot pigweed, careless weed, rough pigweed, redroot amaranth
  Amaranthus spinosus L. – accepted – pigweed, spiny amaranth
  Amaranthus tricolor L. – accepted – Joseph's-coat
  Amaranthus viridis L. – accepted – slender amaranth
  Amaranthus viridus L. – not accepted
  Amaryllis L. – not accepted
  Amaryllis L. – accepted – amaryllis
  Amaryllis atamasca L. – not accepted
  Amaryllis atamasco L. – not accepted
  Amaryllis belladonna L. – accepted – belladonna lily
  Amaryllis reginae L. – not accepted
  Amaryllis zeylanica L. – not accepted
  Amaryllis zeylanicum L. – not accepted
  Ambrosia L. – accepted – ragweed, bursage
  Ambrosia artemisiifolia L. – accepted – annual ragweed, common ragweed, ragweed, low ragweed, Roman wormwood, short ragweed, small ragweed
  Ambrosia artemisiifolia var. artemisiifolia L. – not accepted – annual ragweed, ragweed, common ragweed
  Ambrosia elatior L. – not accepted
  Ambrosia maritima L. – not accepted
  Ambrosia trifida L. – accepted – great ragweed, Texan great ragweed, giant ragweed, tall ragweed, blood ragweed, perennial ragweed, horseweed
  Ambrosia trifida var. trifida L. – not accepted – great ragweed, giant ragweed
  Ammannia L. – accepted – redstem
  Ammannia baccifera L. – accepted – monarch redstem
  Ammannia latifolia L. – accepted – pink redstem
  Ammi L. – accepted
  Ammi copticum L. – not accepted
  Ammi majus L. – accepted – large bullwort
  Amomum cardamomum L. – not accepted
  Amomum zerumbet L. – not accepted
  Amomum zingiber L. – not accepted
  Amorpha L. – accepted – false indigo, indigobush
  Amorpha fruticosa L. – accepted – desert false indigo, dullleaf indigo, false indigobush, leadplant, desert indigobush, indigobush, false indigo
  Amygdalus communis L. – not accepted
  Amygdalus nana L. – not accepted
  Amygdalus persica L. – not accepted
  Amyris balsamifera L. – accepted
  Amyris elemifera L. – accepted – torchwood, sea torchwood
  Amyris toxifera L. – not accepted
  Anacampseros L. – accepted
  Anacardium L. – accepted
  Anacardium occidentale L. – accepted – cashew
  Anacyclus L. – accepted – anacyclus
  Anacyclus valentinus L. – accepted
  Anacylus L. – not accepted – anacyclus
  Anacylus valentinus L. – not accepted
  Anagallis L. – accepted – poorman's weatherglass, pimpernel
  Anagallis arvensis L. – accepted – scarlet pimpernel, pimpernel
  Anagallis arvensis ssp. arvensis L. – not accepted – scarlet pimpernel
  Anagallis linifolia L. – not accepted
  Anagallis monelli L. – accepted – Mediterranean pimpernel, flaxleaf pimpernel
  Anchusa L. – accepted – bugloss
  Anchusa officinalis L. – accepted – alkanet, bugloss, common bugloss
  Anchusa sempervirens L. – not accepted
  Andrachne L. – accepted – maidenbush
  Andrachne telephioides L. – accepted
  Andromeda L. – accepted – bog rosemary
  Andromeda arborea L. – not accepted
  Andromeda arboreum L. – not accepted
  Andromeda caerulea L. – not accepted
  Andromeda calyculata L. – not accepted
  Andromeda coerulea L. – not accepted
  Andromeda polifolia L. – accepted – bog rosemary
  Andromeda polifolia var. polifolia L. – accepted – bog rosemary
  Andropogon L. – accepted – bluestem
  Andropogon alopecuroides L. – not accepted
  Andropogon barbatus L. – not accepted
  Andropogon barbatus L. – not accepted
  Andropogon bicornis L. – accepted – barbas de indio, West Indian foxtail
  Andropogon brevicornis L. – not accepted
  Andropogon caricosus L. – not accepted
  Andropogon contortum L. – not accepted
  Andropogon contortus L. – not accepted
  Andropogon divaricatus L. – not accepted
  Andropogon hirtum L. – not accepted
  Andropogon hirtus L. – not accepted
  Andropogon insulare L. – not accepted
  Andropogon insularis L. – not accepted
  Andropogon ischaemum L. – not accepted
  Andropogon ischaemum var. ischaemum L. – not accepted
  Andropogon nardus L. – not accepted
  Andropogon nutans L. – not accepted
  Andropogon polydactylos L. – not accepted
  Andropogon quadrivalvis L. – not accepted
  Andropogon ravennae L. – not accepted
  Andropogon schoenanthus L. – not accepted
  Andropogon virginicus L. – accepted – broomsedge bluestem, broomsedge, yellow bluestem
  Andropogon virginicus f. virginicus L. – not accepted
  Andropogon virginicus var. virginicus L. – accepted – broomsedge bluestem, broomsedge
  Androsace L. – accepted – rock-jasmine
  Androsace elongata L. – accepted – California rockjasmine
  Androsace elongata L. – not accepted
  Androsace maxima L. – accepted – greater rockjasmine
  Androsace septentrionalis L. – accepted – northern rockjasmine, pygmy-flower rock-jasmine, pygmyflower rockjasmine
  Androsace septentrionalis ssp. septentrionalis L. – not accepted – pygmyflower rockjasmine
  Anemone L. – accepted – anemone
  Anemone canadensis L. – accepted – Canada anemone, Canadian anemone
  Anemone coronaria L. – accepted – lilies-of-the-field
  Anemone hepatica L. – not accepted
  Anemone narcissiflora L. – accepted – narcissus anemone
  Anemone narcissiflora L. – not accepted
  Anemone narcissiflora var. narcissiflora L. – accepted
  Anemone nemorosa L. – accepted – European thimbleweed
  Anemone nemorosa var. nemorosa L. – not accepted – European thimbleweed
  Anemone patens L. – accepted – eastern pasqueflower
  Anemone patens var. patens L. – accepted – eastern pasqueflower
  Anemone pulsatilla L. – accepted – European pasqueflower
  Anemone quinquefolia L. – accepted – nightcaps, wood anemone
  Anemone quinquefolia var. quinquefolia L. – accepted – nightcaps
  Anemone ranunculoides L. – accepted – yellow woodland anemone
  Anemone sylvestris L. – accepted – snowdrop windflower
  Anemone virginiana L. – accepted – Virginia anemone, tall thimbleweed
  Anemone virginiana var. virginiana L. – accepted – tall thimbleweed
  Anethum L. – accepted – dill
  Anethum graveolens L. – accepted – dill
  Angelica L. – accepted – wild celery, angelica
  Angelica archangelica L. – accepted – Norwegian angelica
  Angelica archangelica ssp. archangelica L. – accepted – Norwegian angelica
  Angelica atropurpurea L. – accepted – purplestem angelica
  Angelica lucida L. – accepted – seacoast angelica
  Angelica sylvestris L. – accepted – woodland angelica
  Anguria trifoliata L. – not accepted
  Annona L. – accepted
  Annona glabra L. – accepted – pond apple
  Annona muricata L. – accepted – soursop
  Annona palustris L. – not accepted
  Annona reticulata L. – accepted – custard apple
  Annona squamosa L. – accepted – sweet sop, sugar apple
  Annona triloba L. – not accepted
  Anthemis L. – accepted – chamomile
  Anthemis altissima L. – accepted – tall chamomile
  Anthemis arvensis L. – accepted – corn chamomile, scentless chamomile, mayweed
  Anthemis arvensis var. arvensis L. – not accepted – corn chamomile
  Anthemis cotula L. – accepted – stinking chamomile, dogfennel, mayweed, mayweed dogfennel, dog fennel, mayweed chamomile, stinkweed, chamomile
  Anthemis mixta L. – not accepted
  Anthemis nobilis L. – not accepted
  Anthemis tinctoria L. – not accepted – golden chamomile
  Anthericum L. – accepted
  Anthoceros L. – accepted – hornwort
  Anthoceros laevis L. – not accepted
  Anthoceros punctatus L. – accepted
  Anthoxanthum L. – accepted – vernalgrass
  Anthoxanthum odoratum L. – accepted – sweet vernalgrass
  Anthoxanthum odoratum ssp. odoratum L. – accepted – sweet vernalgrass
  Anthyllis L. – accepted – kidneyvetch
  Anthyllis cornicina L. – accepted
  Anthyllis cytisoides L. – accepted – albaida
  Anthyllis lotoides L. – accepted
  Anthyllis tetraphylla L. – not accepted
  Anthyllis vulneraria L. – accepted – common kidneyvetch, common kidney-vetch
  Antidesma L. – accepted – chinalaurel
  Antirrhinum L. – accepted – snapdragon
  Antirrhinum bellidifolium L. – accepted – lilac snapdragon
  Antirrhinum elatine L. – not accepted
  Antirrhinum majus L. – accepted – garden snapdragon
  Antirrhinum orontium L. – not accepted – lesser snapdragon, linearleaf snapdragon
  Antirrhinum spurium L. – not accepted
  Aphanes L. – accepted – parsley piert
  Aphanes arvensis L. – accepted – field parsley piert
  Apium L. – accepted – wild celery, celery
  Apium graveolens L. – accepted – wild celery
  Apium graveolens L. – not accepted
  Apium graveolens var. graveolens L. – accepted
  Apium petroselinum L. – not accepted
  Apluda L. – accepted – Mauritian grass
  Apluda aristata L. – not accepted
  Apluda mutica L. – accepted – Mauritian grass
  Apluda zeugites L. – not accepted
  Apocynum L. – accepted – dogbane
  Apocynum androsaemifolium L. – accepted – bitterroot, flytrap dogbane, spreading dogbane
  Apocynum androsaemifolium ssp. androsaemifolium L. – not accepted – spreading dogbane
  Apocynum androsaemifolium ssp. androsaemifolium var. androsaemifolium L. – not accepted – spreading dogbane
  Apocynum cannabinum L. – accepted – hemp dogbane, Indian hemp, Indian-hemp, prairie dogbane, dogbane, common dogbane
  Aquilegia L. – accepted – columbine
  Aquilegia canadensis L. – accepted – American columbine, Colorado columbine, honeysuckle, wild columbine, meeting-houses, red columbine
  Aquilegia vulgaris L. – accepted – European columbine
  Arabis L. – accepted – rockcress
  Arabis alpina L. – accepted – alpine rockcress
  Arabis canadensis L. – not accepted – sicklepod, arabette du Canada, sicklepod rockcress
  Arabis lyrata L. – not accepted – lyrate rockcress
  Arabis lyrata var. lyrata L. – not accepted – lyrate rockcress
  Arabis thaliana L. – not accepted
  Arachis L. – accepted – peanut
  Arachis hypogaea L. – accepted – peanut
  Aralia L. – accepted – spikenard
  Aralia chinensis L. – accepted – Chinese angelica tree
  Aralia nudicaulis L. – accepted – wild sarsaparilla
  Aralia racemosa L. – accepted – American spikenard
  Aralia racemosa ssp. racemosa L. – accepted – American spikenard
  Aralia spinosa L. – accepted – devils walkingstick, angelicatree, devil's walkingstick
  Arbutus L. – accepted – madrones
  Arbutus alpina L. – not accepted
  Arbutus unedo L. – accepted – strawberry tree
  Arctium L. – accepted – burdock, burrdock
  Arctium lappa L. – accepted – greater burdock, woodland burdock, bardane, great burdock, greater burrdock
  Arctotis L. – accepted – arctotis
  Arctotis angustifolia L. – accepted
  Areca L. – accepted – areca palm
  Areca catechu L. – accepted – betel palm
  Areca cathecu L. – not accepted
  Arenaria L. – accepted – sandwort
  Arenaria L. – not accepted
  Arenaria ciliata L. – accepted – fringed sandwort
  Arenaria gypsophiloides L. – not accepted
  Arenaria lateriflora L. – not accepted
  Arenaria montana L. – accepted – mountain sandwort
  Arenaria peploides L. – not accepted
  Arenaria serpyllifolia L. – accepted – thymeleaf sandwort
  Arenaria serpyllifolia ssp. serpyllifolia L. – not accepted – thymeleaf sandwort
  Arenaria serpyllifolia var. serpyllifolia L. – accepted – thymeleaf sandwort
  Arenaria verna L. – not accepted
  Arethusa L. – accepted – dragon's mouth
  Arethusa bulbosa L. – accepted – swamp-pink, aréthuse bulbeuse, dragon's mouth
  Argemone L. – accepted – prickly poppy, pricklypoppy
  Argemone mexicana L. – accepted – Mexican prickly poppy, yellow pricklypoppy, Mexican pricklypoppy
  Aristida L. – accepted – threeawn, annual threeawn, perennial threeawn species, perennial threeawn
  Aristida adscensionis L. – accepted – sixweeks threeawn
  Aristida adscensionis var. adscensionis L. – not accepted – sixweeks threeawn
  Aristida americana L. – not accepted
  Aristolochia L. – accepted – dutchman's pipe
  Aristolochia bilabiata L. – accepted – West Indian dutchman's pipe
  Aristolochia bilobata L. – accepted – twolobe dutchman's pipe
  Aristolochia clematitis L. – accepted – birthwort
  Aristolochia erecta L. – accepted – swanflower, dutchman's pipe
  Aristolochia odoratissima L. – accepted – fragrant dutchman's pipe
  Aristolochia peltata L. – accepted – peltate dutchman's pipe
  Aristolochia rotunda L. – accepted
  Aristolochia serpentaria L. – accepted – Virginia snakeroot, Virginia dutchman's pipe
  Aristolochia trilobata L. – accepted – bejuco de santiago
  Arnica L. – accepted – arnica
  Arnica montana L. – accepted – mountain arnica
  Artemisia L. – accepted – sagebrush, wormwood, sagewort
  Artemisia abrotanum L. – accepted – southernwood
  Artemisia absinthium L. – accepted – absinthium, absinth wormwood, absinth sagewort, common sagewort
  Artemisia absinthium var. absinthium L. – not accepted – absinth sagewort
  Artemisia annua L. – accepted – sweet sagewort, annual wormwood
  Artemisia campestris L. – accepted – Pacific wormwood, wormwood sagewort, common sagewort, field sagewort
  Artemisia campestris ssp. campestris L. – accepted – field wormwood, field sagewort
  Artemisia dracunculus L. – accepted – tarragon, green sagewort, wormwood, false tarragon, silky wormwood
  Artemisia dracunculus ssp. dracunculus L. – not accepted – wormwood
  Artemisia maritima L. – accepted – sea wormwood
  Artemisia minima L. – not accepted
  Artemisia pontica L. – accepted – Roman wormwood
  Artemisia rupestris L. – accepted – rock wormwood
  Artemisia rupestris ssp. rupestris L. – not accepted – rock wormwood
  Artemisia vulgaris L. – accepted – common wormwood, hierba de San Juan, mugwort, artemisia
  Artemisia vulgaris var. vulgaris L. – accepted – common wormwood
  Arum L. – accepted
  Arum colocasia L. – not accepted
  Arum esculentum L. – not accepted
  Arum macrorrhizon L. – not accepted
  Arum maculatum L. – accepted – cuckoo pint
  Aruncus L. – accepted
  Arundo L. – accepted – giant reed, arundo
  Arundo arenaria L. – not accepted
  Arundo bambos L. – not accepted
  Arundo donax L. – accepted – giantreed, giant reed
  Arundo donax f. donax L. – accepted
  Arundo donax var. donax L. – accepted – giantreed
  Arundo epigeios L. – not accepted
  Arundo phragmites L. – not accepted
  Asarum L. – accepted – wildginger
  Asarum canadense L. – accepted – Canadian wild ginger, Canadian wildginger
  Asarum virginicum L. – not accepted
  Asclepias L. – accepted – milkweed
  Asclepias curassavica L. – accepted – wild ipecacuanha, bloodflower, hierba de la cucaracha, scarlet milkweed
  Asclepias exaltata L. – accepted – poke milkweed, asclépiade très grande
  Asclepias fruticosa L. – not accepted – African milkweed
  Asclepias incarnata L. – accepted – rose milkweed, swamp milkweed
  Asclepias incarnata ssp. incarnata L. – accepted – swamp milkweed
  Asclepias nivea L. – accepted – Caribbean milkweed, white milkweed
  Asclepias purpurascens L. – accepted – purple milkweed
  Asclepias rubra L. – accepted – red milkweed
  Asclepias syriaca L. – accepted – broadleaf milkweed, common milkweed
  Asclepias tuberosa L. – accepted – butterflyweed, butterfly milkweed
  Asclepias tuberosa ssp. tuberosa L. – accepted – butterfly milkweed
  Asclepias variegata L. – accepted – white milkweed, redring milkweed
  Asclepias verticillata L. – accepted – eastern whorled milkweed, whorled milkweed
  Ascyrum L. – not accepted
  Ascyrum crux-andreae L. – not accepted
  Ascyrum hypericoides L. – not accepted
  Aspalathus L. – accepted – aspalathus
  Aspalathus ebenus L. – not accepted
  Aspalathus quinquefolia L. – accepted
  Aspalatus ebenus L. – not accepted
  Asparagus L. – accepted – asparagus
  Asparagus aethiopicus L. – accepted – Sprenger's asparagus fern
  Asparagus officinalis L. – accepted – asparagus, garden-asparagus, garden asparagus
  Asparagus officinalis ssp. officinalis L. – not accepted
  Asperugo L. – accepted – German-madwort, madwort
  Asperugo procumbens L. – accepted – madwort, German mugwort, German-madwort
  Asperula L. – accepted – woodruff
  Asperula arvensis L. – accepted – blue woodruff
  Asperula odorata L. – not accepted
  Asperula tinctoria L. – not accepted
  Asphodelus L. – accepted – asphodel
  Asphodelus fistulosus L. – accepted – pink asphodel, onionweed
  Asplenium L. – accepted – spleenworts
  Asplenium adiantum-nigrum L. – accepted – black spleenwort
  Asplenium ceterach L. – accepted
  Asplenium dentatum L. – not accepted
  Asplenium erosum L. – not accepted – eared spleenwort
  Asplenium marinum L. – accepted
  Asplenium monanthes L. – accepted – single-sorus spleenwort, singlesorus spleenwort
  Asplenium nidus L. – accepted – Hawai'i birdnest fern
  Asplenium obtusifolium L. – accepted – bluntleaf spleenwort
  Asplenium radicans L. – accepted – dullgreen spleenwort
  Asplenium rhizophyllum L. – accepted – walking fern
  Asplenium ruta-muraria L. – not accepted
  Asplenium ruta-muraria L. – accepted – wallrue, wallrue spleenwort, doradille des murailles
  Asplenium salicifolium L. – accepted – willowleaf spleenwort
  Asplenium scolopendrium L. – not accepted
  Asplenium scolopendrium L. – accepted – Hart's tonguefern
  Asplenium scolopendrium var. scolopendrium L. – accepted – Hart's tonguefern
  Asplenium serratum L. – accepted – wild birdnest fern
  Asplenium trichomanes L. – accepted – maidenhair spleenwort
  Asplenium trichomanes ssp. trichomanes L. – accepted – maidenhair spleenwort
  Asplenium trichomanes-dentatum L. – accepted – maidenhair spleenwort, toothed spleenwort
  Asplenium trichomanes-ramosum L. – accepted – green spleenwort, brightgreen spleenwort
  Aster L. – accepted – aster
  Aster alpinus L. – accepted – alpine aster
  Aster alpinus L. – not accepted
  Aster alpinus var. alpinus L. – accepted – alpine aster
  Aster amellus L. – accepted – Italian aster, Italian starwort
  Aster chinensis L. – not accepted
  Aster concolor L. – not accepted – eastern silver aster
  Aster cordifolius L. – not accepted – common blue wood aster
  Aster cordifolius var. cordifolius L. – not accepted – common blue wood aster
  Aster divaricatus L. – not accepted
  Aster dumosus L. – not accepted – rice button aster
  Aster dumosus var. dumosus L. – not accepted – rice button aster
  Aster ericoides L. – not accepted – heath aster, white aster, white heath aster
  Aster ericoides var. ericoides L. – not accepted – heath aster
  Aster fruticosus L. – not accepted
  Aster grandiflorus L. – not accepted – largeflower aster
  Aster laevis L. – not accepted – smooth aster
  Aster laevis var. laevis L. – not accepted – smooth blue aster
  Aster linariifolius L. – not accepted – flaxleaf aster, aster à feuilles de linaire
  Aster linariifolius var. linariifolius L. – not accepted – flaxleaf aster
  Aster macrophyllus L. – not accepted – bigleaf aster
  Aster macrophyllus var. macrophyllus L. – not accepted – bigleaf aster
  Aster novae-angliae L. – not accepted – New England aster
  Aster novi-belgii L. – not accepted – New Belgium aster
  Aster novi-belgii var. novi-belgii L. – not accepted – New Belgium aster
  Aster puniceus L. – not accepted – purplestem aster
  Aster puniceus var. puniceus L. – not accepted – purplestem aster
  Aster sedifolius L. – accepted
  Aster sibiricus L. – not accepted – Siberian aster
  Aster sibiricus L. – not accepted
  Aster sibiricus var. sibiricus L. – not accepted
  Aster tardiflorus L. – not accepted
  Aster tenuifolius L. – not accepted – saline aster
  Aster tradescantii L. – not accepted
  Aster tradescantii L. – not accepted
  Aster tripolium L. – not accepted – sea aster
  Aster undulatus L. – not accepted – waxyleaf aster
  Aster undulatus var. undulatus L. – not accepted – waxyleaf aster
  Astragalus L. – accepted – milkvetch, astragales, locoweed
  Astragalus alopecuroides L. – accepted
  Astragalus alpinus L. – accepted – alpine milkvetch
  Astragalus alpinus var. alpinus L. – accepted – alpine milkvetch
  Astragalus arenarius L. – accepted
  Astragalus boeticus L. – accepted
  Astragalus canadensis L. – accepted – Canadian milkvetch, Canada milkvetch, Canadian milk-vetch
  Astragalus canadensis var. canadensis L. – accepted – Canadian milkvetch, Canadian milk-vetch
  Astragalus carolinianus L. – not accepted
  Astragalus cicer L. – accepted – chickpea milkvetch, cicer milkvetch
  Astragalus contortuplicatus L. – accepted – Hungarian milkvetch
  Astragalus depressus L. – accepted
  Astragalus epiglottis L. – accepted
  Astragalus galegiformis L. – accepted
  Astragalus glaux L. – accepted
  Astragalus glycyphyllos L. – accepted – licorice milkvetch
  Astragalus hamosus L. – accepted – European milkvetch, milkvetch
  Astragalus incanus L. – accepted
  Astragalus monspessulanus L. – accepted
  Astragalus onobrychis L. – accepted
  Astragalus pentaglottis L. – not accepted
  Astragalus sesameus L. – accepted
  Astragalus sinicus L. – accepted – Chinese milk-vetch
  Astragalus sulcatus L. – accepted
  Astragalus trimestris L. – accepted
  Astragalus vesicarius L. – accepted
  Astrantia L. – accepted – masterwort
  Astrantia major L. – accepted – greater masterwort
  Atragene alpina L. – not accepted
  Atriplex L. – accepted – saltbush
  Atriplex glauca L. – accepted – waxy saltbush
  Atriplex halimus L. – accepted – saltbush
  Atriplex hastata L. – not accepted
  Atriplex hortensis L. – accepted – garden orach, garden orache, mountain-spinach, bledos moles, armuelle mole
  Atriplex hortensis var. rubra L. – not accepted
  Atriplex laciniata L. – accepted – frosted orache
  Atriplex littoralis L. – accepted – grassleaf orache
  Atriplex patula L. – accepted – halberd-leaf orache, spear saltweed, spear saltbush, spear orach, spear-scale, spreading orache
  Atriplex patula ssp. patula L. – not accepted – spear saltbush
  Atriplex patula var. patula L. – not accepted – spear oracle
  Atriplex portulacoides L. – accepted
  Atriplex rosea L. – accepted – redscale saltbush, tumbling orache, redscale saltweed, tumbling saltweed
  Atriplex sibirica L. – accepted – Siberian saltbush
  Atriplex tatarica L. – accepted – Tatarian orache
  Atropa L. – accepted – belladonna
  Atropa bella-donna L. – accepted – belladonna
  Atropa belladonna L. – not accepted
  Atropa physalodes L. – not accepted
  Avena L. – accepted – oat, oats
  Avena elatior L. – not accepted
  Avena elatior var. elatior L. – not accepted
  Avena fatua L. – accepted – wild oat, wild oats, flaxgrass, oatgrass, wheat oats
  Avena fatua ssp. fatua L. – accepted
  Avena fatua var. fatua L. – not accepted
  Avena flavescens L. – not accepted
  Avena fragilis L. – not accepted
  Avena nuda L. – accepted – naked oat
  Avena pensylvanica L. – not accepted
  Avena sativa L. – accepted – common oat, oat, oats, wild oats, Common oats, oatgrass (common)
  Avena spicata L. – not accepted
  Avena sterilis L. – accepted – animated oat
  Avena sterilis ssp. sterilis L. – accepted – animated oat
  Averrhoa L. – accepted
  Averrhoa bilimbi L. – accepted – bilimbi
  Averrhoa carambola L. – accepted – carambola
  Avicennia L. – accepted – black mangrove, mangrove
  Axyris L. – accepted – Russian pigweed
  Axyris amaranthoides L. – accepted – Russian-pigweed, Russian pigweed
  Ayenia L. – accepted
  Azalea lutea L. – not accepted
  Azalea nudiflora L. – not accepted
  Azalea procumbens L. – not accepted
  Azalea procunbens L. – not accepted
  Azalea viscosa L. – not accepted
  Baccharis L. – accepted – baccharis
  Baccharis halimifolia L. – accepted – eastern baccharis
  Baccharis halimifolia L. – not accepted
  Baccharis halimifolia var. halimifolia L. – not accepted
  Baeckea L. – accepted
  Baeckea frutescens L. – accepted
  Ballota L. – accepted – horehound
  Ballota nigra L. – accepted – black horehound
  Ballota nigra var. nigra L. – accepted – black horehound
  Baltimora L. – accepted – baltimora
  Baltimora recta L. – accepted – beautyhead
  Banisteria laurifolia L. – not accepted
  Banisteria lupuloides L. – not accepted
  Banisteria purpurea L. – not accepted
  Barleria L. – accepted – Philippine violet
  Barleria coccinea L. – not accepted
  Barleria cristata L. – accepted – crested Philippine violet
  Barleria prionitis L. – accepted – porcupine flower
  Barleria solanifolia L. – not accepted
  Bartramia indica L. – not accepted
  Bartsia L. – accepted – velvetbells
  Bartsia alpina L. – accepted – velvetbells
  Bartsia trixago L. – not accepted
  Basella L. – accepted
  Basella alba L. – accepted – Ceylon spinach
  Basella rubra L. – not accepted
  Batis maritima L. – accepted – turtleweed, saltwort
  Bauhinia L. – accepted – bauhinia
  Bauhinia aculeata L. – accepted
  Bauhinia divaricata L. – accepted
  Bauhinia purpurea L. – accepted – butterfly tree
  Bauhinia tomentosa L. – accepted – St. Thomas tree
  Bauhinia ungulata L. – accepted – orchidtree
  Bauhinia variegata L. – accepted – mountain ebony, butterfly tree, orchid tree, purple orchid tree
  Befaria aestuans L. – not accepted
  Befaria asturans L. – not accepted
  Begonia L. – accepted – begonias
  Bejaria aestuans L. – accepted
  Bellis L. – accepted – bellis
  Bellis perennis L. – accepted – lawndaisy, English daisy, European daisy, lawn daisy
  Bellonia aspera L. – accepted
  Berberis L. – accepted – holly grape, Oregon-grape, barberry, algerita, berbéris
  Berberis vulgaris L. – accepted – European barberry, epine-vinette, epine-vinette commune, vinetteier, berbéris vulgaire, épine-vinette, common barberry
  Bergia L. – accepted
  Besleria cristata L. – not accepted
  Besleria lutea L. – accepted
  Besleria melittifolia L. – not accepted
  Beta L. – accepted – beet
  Beta maritima L. – not accepted
  Beta vulgaris L. – accepted – common beet
  Beta vulgaris ssp. vulgaris L. – accepted – common beet
  Beta vulgaris var. cicla L. – not accepted
  Betonica officinalis L. – not accepted
  Betula L. – accepted – birch
  Betula alba L. – not accepted
  Betula alnus var. glutinosa L. – not accepted
  Betula lenta L. – accepted – sweet birch
  Betula nana L. – accepted – shrub birch, bog birch, dwarf birch
  Betula nana ssp. nana L. – accepted – swamp birch, Arctic dwarf birch, dwarf birch
  Betula nigra L. – accepted – river birch
  Betula pumila L. – accepted – swamp birch, bog birch
  Betula pumila var. pumila L. – not accepted – bog birch
  Bidens L. – accepted – beggarticks, Spanish needles, beggartick, devil's sticktight
  Bidens bipinnata L. – accepted – Spanish needles, spanish-needles
  Bidens cernua L. – accepted – nodding beggartick, nodding bur-marigold, nodding burr-marigold, bur marigold, nodding beggarticks, nodding bur marigold, sticktight, nodding burmarigold
  Bidens cernua var. cernua L. – not accepted
  Bidens frondosa L. – accepted – devil's beggartick, devil's-pitchfork, sticktight, bur marigold, devil's beggarticks, devil's bootjack, pitchfork weed, sticktights, tickseed sunflower
  Bidens nivea L. – not accepted
  Bidens pilosa L. – accepted – hairy beggarticks, common beggarticks, romerillo, spanish-needles, beggar's ticks, cobbler's pegs, fisi`uli, kofe tonga, matakaro, Spanish needles
  Bidens pilosa var. pilosa L. – not accepted
  Bidens scandens L. – not accepted
  Bidens tripartita L. – accepted – threelobe beggarticks, three-lobe beggarticks
  Bignonia L. – accepted
  Bignonia aequinoctialis L. – not accepted
  Bignonia capreolata L. – accepted – cross vine, crossvine
  Bignonia paniculata L. – not accepted
  Bignonia paniculatum L. – not accepted
  Bignonia radicans L. – not accepted
  Bignonia sempervirens L. – not accepted
  Bignonia stans L. – not accepted
  Bignonia unguis-cati L. – not accepted
  Bignonia unguiscata L. – not accepted
  Bigonia sempervirens L. – not accepted
  Biserrula L. – accepted
  Biserrula pelecinus L. – accepted
  Bixa L. – accepted
  Bixa orellana L. – accepted – lipsticktree, annatto, annatto, roucou
  Blasia L. – accepted
  Blasia pusilla L. – accepted
  Blechnum L. – accepted – midsorus fern
  Blechnum occidentale L. – accepted – hammock fern
  Blechnum orientale L. – not accepted
  Blechnum radicans L. – not accepted
  Blitum capitatum L. – not accepted
  Blitum chenopodioides L. – not accepted
  Blitum virgatum L. – not accepted
  Bocconia L. – accepted
  Bocconia frutescens L. – accepted – parrotweed, sea oxeye daisy, tree poppy, plume poppy
  Boerhavia L. – accepted – spiderling
  Boerhavia diffusa L. – accepted – red spiderling
  Boerhavia erecta L. – accepted – erect spiderling
  Boerhavia repens L. – accepted – anena
  Boerhavia scandens L. – not accepted – wishbone vine, climbing spiderling, climbing wartclub
  Bombax L. – accepted – cottontree
  Bombax ceiba L. – accepted – red silk cottontree
  Bombax pentandrum L. – not accepted
  Bontia L. – accepted
  Bontia daphnoides L. – accepted – white alling
  Bontia germinans L. – not accepted
  Borago L. – accepted – borage
  Borago officinalis L. – accepted – common borage
  Borassus L. – accepted – borassus palm
  Borassus flabellifer L. – accepted – toddy palm
  Brassica L. – accepted – mustard
  Brassica arvensis L. – not accepted
  Brassica campestris L. – not accepted
  Brassica campestris ssp. campestris L. – not accepted
  Brassica chinensis L. – not accepted – pak choi
  Brassica eruca L. – not accepted
  Brassica erucastrum L. – not accepted
  Brassica napus L. – accepted – turnip, rape
  Brassica napus var. napus L. – not accepted – rape, winter rape, summer rape
  Brassica oleracea L. – accepted – cabbage
  Brassica oleracea var. botrytis L. – not accepted – broccoli
  Brassica oleracea var. capitata L. – not accepted – cabbage
  Brassica oleracea var. gongylodes L. – not accepted – kohlrabi
  Brassica oleracea var. oleracea L. – not accepted – cabbage
  Brassica orientalis L. – not accepted
  Brassica rapa L. – accepted – rape mustard, rape, bird's rape, birdsrape mustard, wild mustard, wild rutabaga, wild turnip, turnip rape, field mustard
  Brassica rapa ssp. rapa L. – not accepted
  Brassica rapa var. rapa L. – not accepted – field mustard, bird's rape, common mustard, rape
  Briza L. – accepted – quakinggrass
  Briza eragrostis L. – not accepted
  Briza maxima L. – accepted – big quakinggrass
  Briza media L. – accepted – perennial quakinggrass
  Briza minor L. – accepted – little quakinggrass
  Briza virens L. – not accepted
  Bromelia L. – accepted – bromelia
  Bromelia ananas L. – not accepted
  Bromelia comosa L. – not accepted
  Bromelia pinguin L. – accepted – Piñuela timbiriche, pinguin
  Bromus L. – accepted – brome, brome spp.
  Bromus arvensis L. – accepted – field brome
  Bromus ciliatus L. – accepted – fringed brome
  Bromus ciliatus var. ciliatus L. – not accepted – fringed brome
  Bromus cristatus L. – not accepted
  Bromus distachyos L. – not accepted
  Bromus geniculatus L. – not accepted
  Bromus giganteus L. – not accepted
  Bromus hordeaceus L. – accepted – soft brome, soft chess
  Bromus hordeaceus ssp. hordeaceus L. – accepted – soft brome, downy brome
  Bromus madritensis L. – accepted – compact brome, Spanish brome
  Bromus matritensis L. – not accepted
  Bromus mollis L. – not accepted – soft brome, soft cheat, soft chess
  Bromus pinnatus L. – not accepted
  Bromus purgans L. – not accepted
  Bromus racemosus L. – accepted – bald brome
  Bromus rubens L. – accepted – red brome, foxtail brome
  Bromus scoparius L. – accepted – broom brome
  Bromus scoparius var. scoparius L. – accepted
  Bromus secalinus L. – accepted – rye brome, chess, chess brome, ryebrome, bromegrass, cheat
  Bromus squarrosus L. – accepted – corn brome
  Bromus sterilis L. – accepted – poverty brome, barren bromegrass, sterile brome
  Bromus tectorum L. – accepted – cheatgrass, cheat grass, downy brome, early chess, military grass, wild oats
  Bromus tectorum var. tectorum L. – not accepted – cheatgrass
  Browallia L. – accepted
  Browallia americana L. – accepted – Jamaican forget-me-not
  Brunfelsia L. – accepted – raintree
  Brunfelsia americana L. – accepted – American brunfelsia
  Brunsfelsia L. – not accepted – raintree
  Brunsfelsia americana L. – not accepted – lady of the night
  Bryonia L. – accepted – bryony
  Bryonia alba L. – accepted – white bryony
  Bryonia cretica L. – accepted – Cretan bryony
  Bryonia grandis L. – not accepted
  Bucephalon racemosum L. – not accepted
  Buchnera L. – accepted – bluehearts
  Buchnera americana L. – accepted – bupleurum, American bluehearts
  Bucida L. – accepted
  Bucida buceras L. – not accepted – gregorywood
  Buddleja L. – accepted – butterfly bush, butterflybush
  Bulbocodium serotinum L. – not accepted
  Bunias L. – accepted – wartycabbage
  Bunias erucago L. – accepted – crested wartycabbage
  Bunias orientalis L. – accepted – Turkish wartycabbage
  Bunium L. – accepted – earth-nut
  Bunium bulbocastanum L. – accepted – great pignut, earth-nut
  Buphthalmum L. – accepted – ox eye
  Buphthalmum arborescens L. – not accepted
  Buphthalmum salicifolium L. – accepted – ox-eye
  Bupleurum L. – accepted
  Bupleurum odontites L. – accepted – narrowleaf thorow wax
  Bupleurum ranunculoides L. – accepted
  Bupleurum rotundifolium L. – accepted – hare's-ear, hare's ear
  Burmannia L. – accepted – bluethread
  Burmannia biflora L. – accepted – northern bluethread
  Butomus L. – accepted – butomus
  Butomus umbellatus L. – accepted – flowering rush
  Buxus L. – accepted – boxwood
  Buxus sempervirens L. – accepted – common box
  Cacalia L. – not accepted – cacalia
  Cacalia atriplicifolia L. – not accepted
  Cacalia porophyllum L. – not accepted
  Cacalia sonchifolia L. – not accepted
  Cacalia suaveolens L. – not accepted
  Cactus L. – not accepted
  Cactus cochenilifer L. – not accepted
  Cactus cochenillifera L. – not accepted
  Cactus cochenilliferus L. – not accepted
  Cactus ficus-indica L. – not accepted
  Cactus flagelliformis L. – not accepted
  Cactus melocactus L. – not accepted
  Cactus pentagonus L. – not accepted
  Cactus pereskia L. – not accepted
  Cactus repandus L. – not accepted
  Cactus robinii L. – not accepted
  Caesalpinia L. – accepted – nicker, caesalpinia, poinciana
  Caesalpinia crista L. – accepted – gray nicker
  Caesalpinia sappan L. – accepted – sappanwood
  Calamus L. – accepted – calamus
  Calamus rotang L. – accepted – rattan
  Calceolaria L. – accepted – slipperwort, slipper flower
  Calea oppositifolia L. – not accepted
  Calendula L. – accepted – marigold
  Calendula arvensis L. – accepted – field marigold
  Calendula officinalis L. – accepted – pot marigold, Scotch-marigold, calendula
  Calepina alyssoides L. – not accepted
  Calla L. – accepted – callalily
  Calla aethiopica L. – not accepted
  Calla palustris L. – accepted – water arum, water-dragon
  Callicarpa L. – not accepted
  Callicarpa L. – accepted – beautyberry
  Callicarpa americana L. – accepted – American beautyberry
  Calligonum L. – accepted
  Callitriche L. – not accepted
  Callitriche L. – accepted – water-starwort
  Callitriche autumnalis L. – not accepted
  Callitriche hermaphroditica L. – accepted – northern water-starwort, autumn waterstarwort, autumn water-starwort, northern waterstarwort, scarlet waterstarwort
  Callitriche palustris L. – accepted – vernal water-starwort, spring waterstarwort, spiny waterstarwort, vernal waterstarwort
  Callitriche verna L. – not accepted
  Calophyllum L. – accepted – calophyllum
  Calophyllum calaba L. – accepted
  Calophyllum calabra L. – not accepted
  Calophyllum inophyllum L. – accepted – mastwood, Alexandrian laurel
  Caltha L. – accepted – marsh marigold
  Caltha palustris L. – accepted – yellow marsh-marigold, yellow marshmarigold, yellow marsh marigold
  Caltha palustris var. palustris L. – not accepted – yellow marsh marigold, yellow marsh-marigold
  Calycanthus L. – accepted – sweetshrub
  Calycanthus floridus L. – accepted – eastern sweetshrub, Carolina-allspice
  Calycanthus floridus var. floridus L. – accepted – eastern sweetshrub
  Camellia L. – accepted – tea
  Camellia japonica L. – accepted – camellia
  Campanula L. – accepted – bellflower
  Campanula americana L. – accepted – American bellflower
  Campanula bononiensis L. – accepted – European bellflower
  Campanula cervicaria L. – accepted
  Campanula glomerata L. – accepted – Dane's-blood, Dane's blood
  Campanula latifolia L. – accepted – giant bellflower
  Campanula linifolia L. – not accepted
  Campanula medium L. – accepted – Canterbury bells
  Campanula patula L. – accepted – spreading bellflower
  Campanula persicifolia L. – accepted – peachleaf bellflower
  Campanula rapunculoides L. – accepted – creeping bellflower, rover bellflower, rampion bellflower
  Campanula rotundifolia L. – accepted – bluebell-of-Scotland, roundleaf harebell, bluebell, bluebell bellflower
  Campanula trachelium L. – accepted – bats in the belfry
  Campanula uniflora L. – accepted – arctic bellflower
  Camphorosma L. – accepted
  Camphorosma monspeliaca L. – accepted
  Canarina L. – accepted
  Canarium L. – accepted
  Canarium commune L. – not accepted
  Canarium indicum L. – accepted – Java almond
  Canna L. – accepted – canna
  Canna glauca L. – accepted – maraca amarilla
  Canna indica L. – accepted – purple arrowroot, edible canna, ali'iope, li'iope, poloka, Indian shot
  Cannabis L. – accepted – hemp
  Cannabis sativa L. – accepted – hemp, grass, hashish, Mary Jane, pot, marijuana
  Cannabis sativa ssp. sativa L. – accepted – hemp, grass, hashish, Mary Jane, pot, marijuana
  Cannabis sativa ssp. sativa var. sativa L. – not accepted – marijuana, hemp, grass, hashish, Mary Jane, pot
  Cannabis sativa var. sativa L. – accepted – marijuana
  Capparis L. – accepted – caper
  Capparis baducca L. – not accepted – church blossom, caper
  Capparis cynophallophora L. – not accepted – Jamaican caper
  Capparis spinosa L. – accepted – caper
  Capraria L. – accepted
  Capraria biflora L. – accepted – goatweed
  Capraria crustacea L. – not accepted
  Capraria durantifolia L. – not accepted
  Capsicum L. – accepted – pepper
  Capsicum annuum L. – accepted – cayenne pepper
  Capsicum annuum var. annuum L. – accepted – cayenne pepper
  Capsicum baccatum L. – accepted – locoto
  Capsicum baccatum var. baccatum L. – accepted – locoto, cayenne pepper
  Capsicum frutescens L. – not accepted
  Cardamine L. – accepted – bittercress
  Cardamine bellidifolia L. – accepted – alpine bittercress
  Cardamine bellidifolia var. bellidifolia L. – not accepted – alpine bittercress
  Cardamine hirsuta L. – accepted – hairy bittercress
  Cardamine impatiens L. – accepted – narrowleaf bittercress
  Cardamine parviflora L. – accepted – smallflowered bittercress, sand bittercress
  Cardamine parviflora var. parviflora L. – not accepted – sand bittercress
  Cardamine pratensis L. – accepted – cuckoo flower
  Cardamine pratensis var. pratensis L. – not accepted – cuckoo flower
  Cardamine virginica L. – not accepted
  Cardiospermum L. – accepted – balloonvine
  Cardiospermum corindum L. – accepted – faux-persil, faux persil
  Cardiospermum halicacabum L. – accepted – balloonvine, love in a puff
  Carduus L. – accepted – plumeless thistle
  Carduus acanthoides L. – accepted – spiny plumeless thistle, plumeless thistle, spiny plumeless-thistle
  Carduus acanthoides ssp. acanthoides L. – accepted
  Carduus altissimus L. – not accepted
  Carduus crispus L. – accepted – curly plumeless thistle, curly plumeless-thistle, curled thistle, welted thistle
  Carduus helenioides L. – not accepted
  Carduus lanceolatus L. – not accepted
  Carduus marianus L. – not accepted
  Carduus nutans L. – accepted – nodding plumeless thistle, nodding thistle, musk thistle, nodding plumeless-thistle, chardon penche, plumeless thistle
  Carduus nutans ssp. nutans L. – not accepted – nodding plumeless thistle, musk thistle, nodding thistle
  Carduus pycnocephalus L. – accepted – Italian plumeless thistle, Italian thistle, compact-headed thistle
  Carduus virginianus L. – not accepted
  Carex L. – accepted – laîches, rouches, sedge species, carex, sedges, sedge
  Carex arenaria L. – accepted – sand sedge
  Carex atrata L. – accepted
  Carex canescens L. – accepted – silver sedge, silvery sedge
  Carex canescens ssp. canescens L. – accepted – silvery sedge
  Carex capillaris L. – accepted – hairlike sedge, hair sedge, hair-like sedge
  Carex capitata L. – accepted – arctic sedge, capitate sedge
  Carex capitata ssp. capitata L. – not accepted – capitate sedge
  Carex dioica L. – accepted
  Carex distans L. – accepted – distant sedge
  Carex flava L. – accepted – yellow sedge
  Carex folliculata L. – accepted – long sedge, northern long sedge
  Carex hirta L. – accepted – hammer sedge
  Carex limosa L. – accepted – mud sedge
  Carex loliacea L. – accepted – ryegrass sedge
  Carex muricata L. – accepted – rough sedge
  Carex pallescens L. – accepted – pale sedge
  Carex panicea L. – accepted – grasslike sedge, grass-like sedge
  Carex paniculata L. – accepted
  Carex pilulifera L. – accepted
  Carex pseudocyperus L. – accepted – cypresslike sedge, cypress-like sedge
  Carex pulicaris L. – accepted
  Carex remota L. – accepted
  Carex saxatilis L. – accepted – rock sedge
  Carex saxatilis var. saxatilis L. – not accepted – russet sedge
  Carex squarrosa L. – accepted – squarrose sedge
  Carex tomentosa L. – accepted
  Carex vesicaria L. – accepted – inflated sedge, blister sedge
  Carex vesicaria var. vesicaria L. – not accepted – blister sedge, lesser bladder sedge
  Carex vulpina L. – accepted
  Carica L. – accepted – papaya
  Carica papaya L. – accepted – papaya, pawpaw
  Carissa L. – accepted
  Carissa carandas L. – accepted – karanda
  Carlina L. – accepted – carline thistle
  Carlina vulgaris L. – accepted – carline thistle
  Carlina vulgaris ssp. vulgaris L. – accepted – carline thistle
  Carpinus L. – accepted – hornbeam
  Carpinus betulus L. – accepted – European hornbeam
  Carthamus L. – accepted – distaff thistle
  Carthamus creticus L. – accepted – woolly distaff thistle
  Carthamus lanatus L. – accepted – woolly distaff thistle, distaff thistle, saffron thistle
  Carthamus lanatus ssp. lanatus L. – not accepted – woolly distaff thistle
  Carthamus tinctorius L. – accepted – safflower
  Carum L. – accepted
  Carum carvi L. – accepted – wild caraway, caraway
  Caryocar L. – accepted
  Caryocar nuciferum L. – accepted – souari nut
  Caryophyllus aromaticus L. – not accepted
  Caryota L. – accepted – fishtail palm
  Caryota urens L. – accepted – jaggery palm, solitary fishtail palm
  Cassia L. – accepted – cassia
  Cassia absus L. – not accepted
  Cassia alata L. – not accepted
  Cassia auriculata L. – not accepted – avaram
  Cassia bicapsularis L. – not accepted
  Cassia chamaecrista L. – not accepted
  Cassia diphylla L. – not accepted
  Cassia emarginata L. – not accepted
  Cassia fistula L. – accepted – golden shower
  Cassia flexuosa L. – not accepted
  Cassia glandulosa L. – not accepted
  Cassia hirsuta L. – not accepted
  Cassia javanica L. – accepted – apple blossom
  Cassia javanica var. javanica L. – accepted – apple blossom
  Cassia ligustrina L. – not accepted
  Cassia marilandica L. – not accepted
  Cassia mimosoides L. – not accepted
  Cassia nictitans L. – not accepted
  Cassia obtusifolia L. – not accepted – Java bean, sicklepod
  Cassia occidentalis L. – not accepted – coffee senna, septicweed
  Cassia pilosa L. – not accepted
  Cassia senna L. – not accepted
  Cassia senna L. – not accepted
  Cassia serpens L. – not accepted
  Cassia sophera L. – not accepted
  Cassia tora L. – not accepted
  Cassine L. – accepted
  Cassytha L. – accepted
  Cassytha filiformis L. – accepted – devil's gut
  Casuarina L. – accepted – she-oak
  Casuarina equisetifolia L. – accepted – Australian pine, common ironwood, horsetail casuarina, beach she-oak, Australian-pine, coast she-oak
  Catananche L. – accepted
  Catananche caerulea L. – accepted
  Catesbaea L. – accepted – lilythorn
  Cathamus L. – not accepted
  Cathamus lanatus L. – not accepted
  Cathamus tinctorius L. – not accepted
  Caucalis L. – accepted – burr parsley, bur parsley
  Caucalis latifolia L. – not accepted
  Caucalis platycarpos L. – accepted – carrot burr parsley, carrot bur parsley
  Ceanothus L. – accepted
  Ceanothus americanus L. – accepted – céanothe d'Amérique, Jersey tea, New Jersey tea
  Cedrela odorata L. – accepted – Spanish cedar
  Celastrus L. – accepted – bittersweet
  Celastrus myrtifolius L. – not accepted
  Celastrus scandens L. – accepted – staffvine, waxwork, American bittersweet
  Celosia L. – accepted – cock's comb
  Celosia argentea L. – accepted – silver cock's comb
  Celosia argentea var. argentea L. – not accepted – celosia
  Celosia cristata L. – accepted – crested cock's comb
  Celosia margaritacea L. – not accepted
  Celosia paniculata L. – not accepted
  Celosia trigyna L. – accepted – woolflower
  Celtis L. – accepted – hackberry
  Celtis australis L. – accepted – Mediterranean hackberry, European hackberry, European nettletree, honey-berry
  Celtis occidentalis L. – accepted – hackberry, common hackberry, micocoulier occidental, western hackberry
  Celtis occidentalis var. occidentalis L. – not accepted – common hackberry, western hackberry
  Cenchrus L. – accepted – sandbur, fountaingrass, Kikuyu grass, kikuyugrass
  Cenchrus ciliaris L. – accepted – buffelgrass
  Cenchrus echinatus L. – accepted – southern sandbur, field sandbur, sandburr, burgrass, common sandbur, konpeito-gusa, se mbulabula, vao tui tui
  Cenchrus granularis L. – not accepted
  Cenchrus racemosus L. – not accepted
  Cenchrus tribuloides L. – accepted – sanddune sandbur
  Centaurea L. – accepted – knapweed, star thistle
  Centaurea aspera L. – accepted – rough star-thistle
  Centaurea calcitrapa L. – accepted – red star-thistle, purple starthistle, red star thistle
  Centaurea calcitrapoides L. – accepted – smallhead star-thistle
  Centaurea cineraria L. – accepted – dusty miller
  Centaurea cyanus L. – accepted – garden cornflower, cornflower, bachelor's button
  Centaurea eriophora L. – accepted – wild sandheath
  Centaurea jacea L. – accepted – brownray knapweed, brown knapweed
  Centaurea melitensis L. – accepted – Maltese star-thistle, Malta starthistle, spotted knapweed, tocalote, Maltese star thistle, Napa thistle
  Centaurea montana L. – accepted – mountain knapweed, perennial cornflower, mountain-bluet
  Centaurea moschata L. – not accepted
  Centaurea muricata L. – not accepted
  Centaurea nigra L. – accepted – lesser knapweed, black knapweed
  Centaurea orientalis L. – accepted
  Centaurea paniculata L. – accepted – Jersey knapweed
  Centaurea phrygia L. – accepted – wig knapweed
  Centaurea repens L. – not accepted – Russian knapweed, hardheads
  Centaurea salmantica L. – not accepted
  Centaurea scabiosa L. – accepted – greater knapweed, scabious knapweed, greater centaury
  Centaurea solstitialis L. – accepted – yellow star-thistle, yellow starthistle, yellow star thistle
  Centaurea stoebe L. – accepted – spotted knapweed
  Centaurea stoebe ssp. stoebe L. – accepted – spotted knapweed
  Centella L. – accepted
  Centella villosa L. – accepted
  Centunculus L. – not accepted
  Centunculus minimus L. – not accepted
  Cephalanthus L. – accepted – buttonbush
  Cephalanthus occidentalis L. – accepted – buttonbush, common buttonbush
  Cerastium L. – accepted – chickweed, mouse-ear chickweed
  Cerastium alpinum L. – accepted – alpine chickweed
  Cerastium alpinum ssp. alpinum L. – accepted – alpine chickweed
  Cerastium alpinum ssp. alpinum var. alpinum L. – not accepted – alpine chickweed
  Cerastium aquaticum L. – not accepted
  Cerastium arvense L. – accepted – field mouse-ear chickweed, starry chickweed, field chickweed
  Cerastium arvense ssp. arvense L. – accepted – field chickweed
  Cerastium dichotomum L. – accepted – forked chickweed
  Cerastium latifolium L. – not accepted
  Cerastium maximum L. – accepted – great chickweed
  Cerastium semidecandrum L. – accepted – fivestamen chickweed
  Cerastium strictum L. – not accepted
  Cerastium tomentosum L. – accepted – snow in summer
  Ceratonia L. – accepted
  Ceratonia siliqua L. – accepted – St. John's bread, carob
  Ceratophyllum L. – accepted – hornwort
  Ceratophyllum demersum L. – accepted – coon's-tail, coontail, hornwort, common hornwort, coon's tail
  Ceratophyllum submersum L. – accepted – soft hornwort
  Cerbera L. – accepted
  Cerbera manghas L. – accepted – reva
  Cerbera thevetia L. – not accepted
  Cercis L. – accepted – redbud
  Cercis canadensis L. – accepted – eastern redbud, redbud
  Cercis canadensis var. canadensis L. – accepted – eastern redbud, redbud
  Cercis siliquastrum L. – accepted – Judas-tree, lovetree
  Cerinthe L. – accepted – honeywort
  Cerinthe major L. – accepted – honeywort
  Ceropegia L. – accepted
  Ceropegia candelabrum L. – accepted
  Ceropegia candelabrum var. candelabrum L. – accepted
  Cestrum L. – accepted – jessamine, flowering jessamine
  Cestrum diurnum L. – accepted – day jessamine, day flowering jessamine, day cestrum, day jasmine, inkberry, tentanchinu, thauthau, tintan china
  Cestrum diurnum var. diurnum L. – not accepted – day jessamine, day flowering jessamine
  Cestrum nocturnum L. – accepted – night jessamine, dama-de-noche, iki he po, night cestrum, night jasmine, queen of the night, thauthau ni mbongi, night flowering jessamine
  Chaerophyllum L. – accepted – chervil
  Chaerophyllum aromaticum L. – accepted
  Chaerophyllum bulbosum L. – accepted – turniproot chervil, turnip-root chervil
  Chaerophyllum sylvestre L. – not accepted
  Chaerophyllum temulum L. – accepted – rough chervil
  Chamaecyparis cupressus L. – not accepted
  Chamaerops L. – accepted – fan palm
  Chamaerops humilis L. – accepted – European fan palm
  Cheiranthus cheiri L. – not accepted
  Chelidonium L. – accepted – celandine
  Chelidonium corniculatum L. – not accepted
  Chelidonium majus L. – accepted – celandine
  Chelidonium majus var. majus L. – not accepted – celandine
  Chelone L. – accepted – turtlehead
  Chelone glabra L. – accepted – white turtlehead
  Chelone glabra var. glabra L. – not accepted – white turtlehead
  Chelone obliqua L. – accepted – red turtlehead
  Chelone obliqua var. obliqua L. – accepted – red turtlehead
  Chenopodium L. – accepted – goosefoot
  Chenopodium album L. – accepted – common lambsquarters, lambsquarters goosefoot, white goosefoot, lambsquarters
  Chenopodium album ssp. album L. – not accepted – lambsquarters
  Chenopodium album var. album L. – not accepted – common lambsquarters, white goosefoot, lambsquarters
  Chenopodium ambrosioides L. – not accepted – Mexican-tea, Mexican tea
  Chenopodium ambrosioides var. ambrosioides L. – not accepted – Mexican tea
  Chenopodium aristatum L. – not accepted – wormseed
  Chenopodium bonus-henricus L. – accepted – good King Henry
  Chenopodium botrys L. – not accepted – Jerusalem-oak, Jerusalem oak, Jerusalem oak goosefoot
  Chenopodium glaucum L. – accepted – oak-leaf goosefoot, oakleaf goosefoot
  Chenopodium glaucum var. glaucum L. – accepted – oakleaf goosefoot
  Chenopodium multifidum L. – not accepted – cutleaf goosefoot
  Chenopodium murale L. – accepted – nettle-leaf goosefoot, nettleleaf goosefoot
  Chenopodium polyspermum L. – accepted – manyseed goosefoot
  Chenopodium polyspermum var. polyspermum L. – accepted – manyseed goosefoot
  Chenopodium rubrum L. – accepted – red goosefoot
  Chenopodium rubrum var. rubrum L. – accepted – red goosefoot
  Chenopodium urbicum L. – accepted – city goosefoot
  Chenopodium viride L. – not accepted
  Chenopodium vulvaria L. – accepted – stinking goosefoot
  Chiococca racemosa L. – not accepted
  Chionanthus L. – accepted – fringetree
  Chionanthus virginicus L. – accepted – fringetree, white fringetree
  Chionanthus virginicus var. virginicus L. – not accepted – white fringetree
  Chironia dodecandra L. – not accepted
  Chlidonium L. – not accepted
  Chlidonium majus L. – not accepted
  Chondrilla L. – not accepted
  Chondrilla L. – accepted – chondrilla
  Chondrilla juncea L. – accepted – rush skeletonweed, hogbite, skeletonweed
  Chrysanthemum L. – accepted – daisy
  Chrysanthemum alpinum L. – not accepted
  Chrysanthemum arcticum L. – accepted – arctic daisy
  Chrysanthemum arcticum ssp. arcticum L. – not accepted
  Chrysanthemum bipinnatum L. – not accepted
  Chrysanthemum coronarium L. – not accepted – crowndaisy
  Chrysanthemum coronarium var. coronarium L. – not accepted – garland chrysanthemum
  Chrysanthemum corymbosum L. – not accepted
  Chrysanthemum frutescens L. – not accepted – marguerite
  Chrysanthemum indicum L. – not accepted
  Chrysanthemum leucanthemum L. – not accepted – ox-eye daisy, oxeye daisy
  Chrysanthemum segetum L. – not accepted – corndaisy
  Chrysanthemum serotinum L. – not accepted
  Chrysobalanus L. – accepted
  Chrysobalanus icaco L. – accepted – icaco coco plum, icaco, coco plum
  Chrysobalanus icaco ssp. icaco L. – accepted – icaco, coco plum
  Chrysocoma graminifolia L. – not accepted
  Chrysogonum L. – accepted – chrysogonum
  Chrysogonum virginianum L. – accepted – green and gold
  Chrysogonum virginianum var. virginianum L. – accepted – green and gold
  Chrysophyllum L. – accepted – goldenleaf
  Chrysophyllum cainito L. – accepted – star apple
  Chrysophyllum oliviforme L. – accepted – saffron-tree, damson-plum, satinleaf
  Chrysosplenium L. – accepted – golden saxifrage
  Cicca disticha L. – not accepted
  Cicer L. – accepted
  Cicer arietinum L. – accepted – chick pea
  Cichorium L. – accepted – chicory, chickory
  Cichorium endivia L. – accepted – cultivated endive
  Cichorium intybus L. – accepted – chicory, French endive, succory, chickory, blue sailors, coffeeweed, common chicory
  Cicuta L. – accepted – water hemlock
  Cicuta bulbifera L. – accepted – bulb waterhemlock, bulblet-bearing water-hemlock, bulblet-bearing water hemlock
  Cicuta maculata L. – accepted – water hemlock, common water hemlock, poison parsnip, spotted cowbane, spotted parsley, spotted water-hemlock, spotted waterhemlock, spotted water hemlock
  Cicuta maculata var. maculata L. – accepted – water hemlock, common water hemlock, poison parsnip, spotted cowbane, spotted parsley, spotted water-hemlock, spotted water hemlock
  Cicuta virosa L. – accepted – Mackenzie's water hemlock
  Cinchona L. – accepted
  Cinchona officinalis L. – accepted – quinine
  Cineraria L. – accepted – cineraria
  Cinna L. – accepted – woodreed
  Cinna arundinacea L. – accepted – sweet woodreed, stout wood reed-grass, stout woodreed, sweet wood-reed
  Cinna arundinacea var. arundinacea L. – not accepted – sweet woodreed
  Circaea L. – accepted – enchanter's nightshade
  Circaea alpina L. – accepted – alpine circaea, small enchanter's-nightshade, small enchanter's nightshade
  Circaea alpina ssp. alpina L. – accepted – small enchanter nightshade, small enchanter's-nightshade, small enchanter's nightshade
  Circaea lutetiana L. – accepted – broadleaf enchanter's nightshade
  Circaea lutetiana L. – not accepted
  Circaea lutetiana var. canadensis L. – not accepted
  Cissampelos L. – accepted
  Cissampelos pareira L. – accepted – pareira brava, velvetleaf
  Cissus L. – accepted – treebind, treebine
  Cissus quadrangularis L. – accepted – veldt-grape
  Cissus sicyoides L. – not accepted
  Cistus L. – accepted – rockrose
  Cistus canadensis L. – not accepted
  Cistus creticus L. – not accepted
  Cistus guttatus L. – not accepted
  Cistus incanus L. – accepted – hairy rockrose
  Cistus incanus ssp. incanus L. – not accepted – hairy rockrose
  Cistus ladanifer L. – accepted – common gum cistus, labdanum, jara
  Cistus ladaniferus L. – not accepted – gum rockrose
  Cistus monspeliensis L. – accepted – Montpelier cistus
  Cistus salviifolius L. – accepted – salvia cistus
  Citharexylum L. – accepted – fiddlewood
  Citharexylum caudatum L. – accepted – juniper berry
  Citharexylum fruticosum L. – not accepted – Florida fiddlewood
  Citharexylum fruticosum var. fruticosum L. – not accepted – Florida fiddlewood
  Citharexylum spinosum L. – accepted – fiddlewood, spiny fiddlewood
  Citrus L. – accepted – citrus
  Citrus aurantium L. – not accepted – sour orange
  Citrus aurantium ssp. aurantium L. – not accepted – sour orange
  Citrus aurantium var. sinensis L. – not accepted
  Citrus medica L. – accepted – citron
  Citrus trifoliata L. – not accepted
  Citrus X aurantium ssp. aurantium L. – not accepted – sour orange
  Claytonia L. – accepted – springbeauty
  Claytonia sibirica L. – accepted – Siberian springbeauty
  Claytonia sibirica var. sibirica L. – not accepted – Siberian springbeauty
  Claytonia virginica L. – accepted – narrow-leaved spring beauty, claytonie de Virginie, Spring beauty, Virginia springbeauty
  Claytonia virginica var. virginica L. – not accepted – Virginia springbeauty
  Clematis L. – accepted – clematis, leather flower
  Clematis cirrhosa L. – accepted
  Clematis crispa L. – accepted – curly virginsbower, swamp leather flower
  Clematis dioica L. – accepted – cabellos de angel
  Clematis flammula L. – accepted – fragrant clematis
  Clematis integrifolia L. – accepted
  Clematis orientalis L. – accepted – oriental virginsbower, Chinese clematis
  Clematis recta L. – accepted – ground virginsbower
  Clematis viorna L. – accepted – vasevine
  Clematis virginiana L. – accepted – virgin's bower, devil's-darning-needles, Virginia bower, devil's darning needles
  Clematis vitalba L. – accepted – traveler's-joy, old-man's-beard, evergreen clematis
  Clematis viticella L. – accepted – Italian leather flower
  Cleome L. – accepted – spider flower, beeplant, spiderflower
  Cleome aculeata L. – not accepted – prickly spiderflower
  Cleome gynandra L. – not accepted – spider whisp, spiderflower, spiderwisp
  Cleome icosandra L. – not accepted
  Cleome ornithopodioides L. – accepted – bird spiderflower
  Cleome pentaphylla L. – not accepted
  Cleome viscosa L. – not accepted – Asian spiderflower
  Clerodendrum L. – accepted – glorybower
  Clethra L. – accepted – sweet pepperbush, sweetpepperbush
  Clethra alnifolia L. – accepted – summersweet, summersweet clethra, coastal sweetpepperbush, coastal sweet pepperbush
  Clethra alnifolia L. – not accepted
  Clibadium L. – accepted – clibadium
  Clibadium surinamense L. – accepted
  Clinopodium L. – accepted
  Clinopodium incanum L. – not accepted
  Clinopodium vulgare L. – accepted – wild basil
  Clitoria L. – accepted – pigeonwings
  Clitoria mariana L. – accepted – Atlantic pigeonwings, butterfly-pea, pigeonwings
  Clitoria mariana var. mariana L. – accepted – Atlantic pigeonwings, butterfly-pea
  Clitoria ternatea L. – accepted – Asian pigeonwings
  Clitoria ternatea var. ternatea L. – accepted – Asian pigeonwings
  Clusia L. – not accepted
  Clusia L. – accepted – attorney
  Clusia minor L. – accepted – cupey de monte
  Clutia cascarilla L. – not accepted
  Clutia eluteria L. – not accepted
  Clypeola alyssoides L. – not accepted
  Clypeola maritima L. – not accepted
  Clypeola minor L. – not accepted
  Clypeola minus L. – not accepted
  Cnicus L. – not accepted – cnicus
  Cnicus benedictus L. – not accepted – blessed thistle, blessed-thistle
  Coccoloba pubescens L. – accepted – grandleaf seagrape
  Coccoloba tenuifolia L. – accepted – Bahama pigeonplum
  Coccoloba venosa L. – accepted – false chiggergrape
  Cochlearia L. – accepted – scurvygrass
  Cochlearia armoracia L. – not accepted
  Cochlearia danica L. – accepted – early scurvygrass
  Cochlearia groenlandica L. – accepted – Danish scurvygrass
  Cochlearia officinalis L. – accepted – common scurvygrass, spoonwort
  Cocos L. – accepted – coconut palm
  Cocos nucifera L. – accepted – niu, ololani, cocotier, coconut palm, Palma de Coco
  Coffea L. – accepted – coffee
  Coffea arabica L. – accepted – Arabian coffee
  Coix L. – accepted – Job's tears
  Coix dactyloides L. – not accepted
  Coix lacryma L. – not accepted
  Coix lacryma-jobi L. – accepted – Job's tears
  Coix lacryma-jobi var. lacryma-jobi L. – accepted
  Colchicum L. – accepted – colchicum
  Colchicum autumnale L. – accepted – autumn crocus
  Coldenia L. – accepted
  Collinsonia L. – accepted – horsebalm
  Collinsonia canadensis L. – accepted – richweed
  Columnea L. – accepted
  Columnea scandens L. – accepted – tibey parasito
  Colutea L. – accepted
  Colutea arborescens L. – accepted – bladder senna, bladdersenna
  Comarum L. – accepted
  Comarum palustre L. – accepted – purple marshlocks
  Commelina L. – accepted – commelina, dayflower
  Commelina benghalensis L. – accepted – day flower, hairy honohono, Benghal dayflower, jio
  Commelina communis L. – accepted – common dayflower, Asiatic dayflower
  Commelina communis var. communis L. – not accepted – Asiatic dayflower
  Commelina erecta L. – accepted – erect dayflower, whitemouth dayflower
  Commelina erecta var. erecta L. – not accepted – whitemouth dayflower
  Commelina nudiflora L. – not accepted
  Commelina spirata L. – not accepted
  Commelina tuberosa L. – accepted – commelina
  Commelina virginica L. – accepted – Virginia dayflower
  Commelina zanonia L. – not accepted
  Conium L. – accepted – poison hemlock
  Conium maculatum L. – accepted – cigue maculee, cigue tachetee, deadly hemlock, poison parsley, poison-hemlock, poison hemlock
  Connarus L. – accepted
  Conocarpus L. – accepted – mangrove
  Conocarpus erectus L. – accepted – button mangrove
  Conocarpus racemosa L. – not accepted
  Convallaria L. – accepted – lily of the valley, convallaria
  Convallaria fruticosa L. – not accepted
  Convallaria majalis L. – accepted – lily-of-the-valley, European lily of the valley
  Convallaria majalis var. majalis L. – accepted – European lily of the valley
  Convallaria racemosa L. – not accepted
  Convallaria stellata L. – not accepted
  Convallaria trifolia L. – not accepted
  Convolvulus L. – accepted – field bindweed, bindweed
  Convolvulus althaeoides L. – accepted – mallow bindweed
  Convolvulus arvensis L. – accepted – creeping jenny, European bindweed, perennial morningglory, smallflowered morningglory, field bindweed
  Convolvulus batatas L. – not accepted – sweet potato
  Convolvulus carolinus L. – not accepted
  Convolvulus corymbosus L. – not accepted
  Convolvulus hederaceus L. – not accepted
  Convolvulus muricatus L. – not accepted
  Convolvulus nil L. – not accepted
  Convolvulus nummularius L. – not accepted
  Convolvulus pes-caprae L. – not accepted
  Convolvulus purpureus L. – not accepted – tall morningglory
  Convolvulus repens L. – not accepted
  Convolvulus scammonia L. – accepted – scammony
  Convolvulus sepium L. – not accepted – hedge false bindweed
  Convolvulus soldanella L. – not accepted
  Convolvulus spithamaeus L. – not accepted
  Convolvulus tricolor L. – accepted – dwarf morning-glory
  Convolvulus umbellatus L. – not accepted
  Conyza asteroides L. – not accepted
  Conyza cinerea L. – not accepted
  Conyza linifolia L. – not accepted
  Conyza lobata L. – not accepted
  Conyza odorata L. – not accepted
  Copaifera L. – accepted
  Corchorus L. – accepted
  Corchorus aestuans L. – accepted – jute, East Indian mallow, West African mallow
  Corchorus capsularis L. – accepted – jute
  Corchorus hirsutus L. – accepted – jackswitch, woolly corchorus, mallet, cadillo
  Corchorus hirtus L. – accepted – Orinoco jute, red jute
  Corchorus hirtus var. hirtus L. – not accepted
  Corchorus olitorius L. – accepted – nalta jute
  Corchorus siliquosus L. – accepted – slippery burr, broomweed
  Corchorus tridens L. – accepted – wild jute, horn-fruited jute
  Corchorus trilocularis L. – accepted – threelocule corchorus
  Cordia L. – accepted
  Cordia collococca L. – accepted – clammy cherry, red manjack
  Cordia gerascanthus L. – accepted – yauco
  Cordia myxa L. – accepted – Assyrian plum
  Cordia sebestena L. – accepted – largeleaf geigertree
  Coreopsis L. – accepted – tickseed, coreopsis
  Coreopsis alba L. – not accepted
  Coreopsis auriculata L. – accepted – lobed tickseed
  Coreopsis lanceolata L. – accepted – lanceleaf tickseed, lance coreopsis
  Coreopsis reptans L. – not accepted
  Coreopsis tripteris L. – accepted – tall tickseed, Atlantic coreopsis
  Coreopsis verticillata L. – accepted – whorled tickseed
  Coriandrum L. – accepted – coriander
  Coriandrum sativum L. – accepted – Chinese-parsley, Chinese parsley, coriander
  Coriospermum L. – not accepted
  Coriospermum hyssopifolium L. – not accepted
  Corispermum L. – accepted – bugseed
  Corispermum hyssopifolium L. – accepted – hyssop-leaved bugseed
  Cornus L. – accepted – dogwood
  Cornus alba L. – not accepted – Tatarian dogwood, Siberian dogwood
  Cornus canadensis L. – accepted – Canadian bunchberry, bunchberry dogwood
  Cornus florida L. – accepted – flowering dogwood
  Cornus mas L. – accepted – Cornelian cherry, sorbet, cornejo macho
  Cornus sanguinea L. – accepted – bloodtwig dogwood, dogberry, common dogwood, pegwood
  Cornus sericea L. – accepted – redosier, redosier dogwood
  Cornus sericea ssp. sericea L. – accepted – redosier dogwood, Tatarian dogwood, Siberian dogwood
  Cornus suecica L. – accepted – Lapland cornel
  Cornutia L. – accepted
  Cornutia pyramidata L. – accepted – azulejo
  Coronilla L. – accepted – crownvetch
  Coronilla argentea L. – not accepted
  Coronilla coronata L. – accepted
  Coronilla cretica L. – not accepted – Cretan crownvetch
  Coronilla emerus L. – not accepted – scorpion senna
  Coronilla juncea L. – accepted
  Coronilla minima L. – accepted
  Coronilla securidaca L. – not accepted – goat pea
  Coronilla valentina L. – accepted – Mediterranean crownvetch
  Coronilla varia L. – not accepted – crownvetch, purple crownvetch, purple crown-vetch, Varia crownvetch
  Corrigiola L. – accepted
  Corrigiola litoralis L. – accepted – strapwort
  Corrigiola litoralis ssp. litoralis L. – accepted – strapwort
  Corylus L. – accepted – hazelnut
  Corylus avellana L. – accepted – common filbert
  Corylus colurna L. – accepted – Turkish hazelnut
  Corylus colurna var. colurna L. – not accepted – Turkish hazelnut
  Costus L. – accepted – costus
  Cotula L. – accepted – waterbuttons, water buttons
  Cotula coronopifolia L. – accepted – common brassbuttons, brassbuttons
  Cotula verbesina L. – not accepted
  Cotula viscosa L. – not accepted
  Cotyledon L. – accepted – pig's ear
  Cotyledon orbiculata L. – accepted – pig's ear
  Cracca purpurea L. – not accepted
  Cracca virginiana L. – not accepted
  Crambe L. – accepted
  Crambe hispanica L. – accepted – Hispanic crambe
  Crambe maritima L. – accepted – sea kale
  Craniolaria L. – accepted
  Craniolaria annua L. – accepted – escorzonera
  Craniolaria fruticosa L. – not accepted
  Crassula L. – accepted – pygmyweed
  Crassula perfoliata L. – accepted
  Crassula tetragona L. – accepted
  Crataegus L. – accepted – hawthorns, aubépines
  Crataegus azarolus L. – accepted – azarole, Mediterranean-medlar
  Crataegus coccinea L. – accepted – scarlet hawthorn, red-fruited hawthorn, red haw
  Crataegus coccinea L. – not accepted
  Crataegus coccinea var. coccinea L. – accepted – scarlet hawthorn
  Crataegus crus-galli L. – accepted – aubépine ergot-de-coq, bush hawthorn, cockspur hawthorn
  Crataegus crus-galli var. crus-galli L. – accepted – cockspur hawthorn
  Crataegus torminalis L. – not accepted
  Crataegus viridis L. – not accepted
  Crataegus viridis L. – accepted – green hawthorn
  Crataegus viridis var. viridis L. – accepted – green hawthorn
  Crateva L. – accepted
  Crateva tapia L. – accepted
  Crepis L. – accepted – hawksbeard
  Crepis barbata L. – not accepted
  Crepis biennis L. – accepted – rough hawksbeard
  Crepis bursifolia L. – accepted – Italian hawksbeard
  Crepis foetida L. – accepted – stinking hawksbeard
  Crepis foetida var. foetida L. – not accepted
  Crepis pulchra L. – accepted – smallflower hawksbeard, hawksbeard
  Crepis rubra L. – accepted – red hawksbeard
  Crepis tectorum L. – accepted – narrowleaf hawksbeard, narrowleaved hawk's beard, narrow-leaf hawk's-beard
  Crepis vesicaria L. – accepted – beaked hawksbeard
  Crepis vesicaria ssp. vesicaria L. – not accepted
  Crepis vesicaria var. vesicaris L. – not accepted
  Crescentia L. – accepted
  Crescentia cujete L. – accepted – common calabash tree
  Cressa L. – not accepted
  Cressa L. – accepted – alkaliweed
  Crinum L. – accepted – swamplily
  Crinum americanum L. – accepted – seven sisters
  Crinum americanum var. americanum L. – accepted – seven sisters
  Crinum asiaticum L. – accepted – poisonbulb
  Crocus L. – accepted – crocus
  Crocus sativus L. – accepted – saffron crocus
  Crotalaria L. – accepted – rattlebox
  Crotalaria alba L. – not accepted
  Crotalaria biflora L. – accepted – twoflower rattlebox
  Crotalaria incana L. – accepted – shakeshake
  Crotalaria juncea L. – accepted – sunn hemp
  Crotalaria laburnifolia L. – accepted
  Crotalaria lotifolia L. – accepted – cascabelillo axilar
  Crotalaria quinquefolia L. – accepted
  Crotalaria retusa L. – accepted – rattleweed
  Crotalaria sagittalis L. – accepted – arrowhead rattlebox, arrow crotalaria
  Crotalaria verrucosa L. – accepted – blue rattlesnake
  Croton L. – accepted
  Croton argenteus L. – accepted – silver July croton
  Croton aromaticus L. – accepted
  Croton castaneifolius L. – not accepted
  Croton flavens L. – accepted – yellow balsam, yellow croton
  Croton glabellus L. – accepted
  Croton glabellus ssp. glabellus L. – accepted
  Croton glandulosus L. – accepted – tropic croton, tooth-leaved croton, sand croton, vente conmigo
  Croton glandulosus var. glandulosus L. – accepted – vente conmigo
  Croton hastatus L. – not accepted
  Croton humilis L. – accepted – low croton, pepperbush
  Croton laccifer L. – accepted
  Croton lobatus L. – not accepted – lobed croton
  Croton lobatus var. seemannii L. – not accepted
  Croton lobatus var. sericeus L. – not accepted
  Croton lucidus L. – accepted – firebush
  Croton moluccanus L. – not accepted
  Croton palustris L. – not accepted
  Croton ricinocarpus L. – not accepted
  Croton sebiferum L. – not accepted
  Croton spinosus L. – not accepted
  Croton subtomentosus L. – not accepted
  Croton tiglium L. – accepted – purging croton
  Croton tinctoria L. – not accepted
  Croton tinctorius L. – not accepted
  Croton urens L. – not accepted
  Croton variegatus L. – not accepted
  Crucianella L. – accepted
  Crucianella angustifolia L. – accepted – narrowleaf crucianella
  Cucubalus sibiricus L. – not accepted
  Cucubertia citrullus L. – not accepted
  Cucumis L. – accepted – melon
  Cucumis acutangulus L. – not accepted
  Cucumis anguria L. – accepted – West Indian gherkin, bur gherkin
  Cucumis anguria var. anguria L. – accepted – West Indian gherkin
  Cucumis colocynthis L. – not accepted
  Cucumis melo L. – accepted – cantaloupe, honeydew, muskmelon
  Cucumis melo ssp. melo L. – accepted
  Cucumis prophetarum L. – accepted – cucumis
  Cucumis sativus L. – accepted – garden cucumber
  Cucumis sativus var. sativus L. – accepted
  Cucurbita L. – accepted – gourd
  Cucurbita lagenaria L. – not accepted
  Cucurbita melopepo L. – accepted – spaghetti squash, summer squash, straight squash, acorn squash, crookneck squash, pattypan squash, scallop squash
  Cucurbita melopepo ssp. melopepo L. – accepted – scallop squash, pattypan squash, crookneck squash, acorn squash, straight squash, summer squash, spaghetti squash
  Cucurbita melopepo var. melopepo L. – accepted
  Cucurbita ovifera L. – not accepted
  Cucurbita pepo L. – accepted – vegetable marrow, field pumpkin, jack-o-lantern pumpkin, zucchini, cocozelle, citrouille
  Cucurbita pepo ssp. pepo L. – accepted
  Cucurbita pepo var. pepo L. – not accepted – field pumpkin
  Cumimum L. – not accepted
  Cumimum cyminum L. – not accepted
  Cuminum L. – accepted – cumin
  Cuminum cyminum L. – accepted – cumin
  Cunila mariana L. – not accepted
  Cunila marina L. – not accepted
  Cunila pulegioides L. – not accepted
  Cupania L. – accepted
  Cupania americana L. – accepted – wild ackee
  Cupressus L. – accepted – cypress
  Cupressus disticha L. – not accepted
  Cupressus sempervirens L. – accepted – Italian cypress
  Cupressus thyoides L. – not accepted
  Curcuma L. – accepted – hidden-lily
  Curcuma longa L. – accepted – turmeric, common turmeric
  Cuscuta L. – accepted – dodder
  Cuscuta americana L. – accepted – American dodder
  Cuscuta europaea L. – accepted – greater dodder
  Cyathea pygmaea L. – accepted
  Cycas L. – accepted – cycad
  Cycas circinalis L. – accepted – queen sago
  Cycas circinalis var. circinalis L. – not accepted
  Cyclamen L. – accepted
  Cyclamen europaeum L. – not accepted
  Cymanchum L. – not accepted
  Cynanchum L. – accepted – swallowwort, swallow-wort
  Cynara L. – accepted – cynara
  Cynara cardunculus L. – accepted – cardoon, artichoke, artichoke thistle, wild artichoke
  Cynara cardunculus ssp. cardunculus L. – accepted – cardoon, artichoke, artichoke thistle
  Cynara scolymus L. – accepted – globe artichoke
  Cynoglossum L. – accepted – hound's tongue
  Cynoglossum linifolium L. – not accepted
  Cynoglossum officinale L. – accepted – houndstongue, gypsy-flower, common houndstongue, hound's tongue, gypsyflower
  Cynoglossum virginianum L. – accepted – blue houndstongue, wild comfrey
  Cynoglossum virginianum var. virginianum L. – accepted – wild comfrey
  Cynometra L. – accepted
  Cynometra ramiflora L. – accepted
  Cynosurus L. – accepted – dogstail grass
  Cynosurus aegyptius L. – not accepted
  Cynosurus aureus L. – not accepted
  Cynosurus coracanus L. – not accepted
  Cynosurus cristatus L. – accepted – crested dogstail grass
  Cynosurus durus L. – not accepted
  Cynosurus echinatus L. – accepted – bristly dogstail grass
  Cynosurus indicus L. – not accepted
  Cynosurus virgatus L. – not accepted
  Cyperus L. – accepted – nutgrass, flatsedge
  Cyperus articulatus L. – accepted – jointed flatsedge
  Cyperus compressus L. – accepted – poorland flatsedge
  Cyperus difformis L. – accepted – smallflower umbrella sedge, variable flatsedge
  Cyperus elegans L. – accepted – sticky flatsedge, royal flatsedge
  Cyperus esculentus L. – accepted – chufa flatsedge, chufa, yellow nutgrass, yellow nutsedge
  Cyperus esculentus L. – not accepted
  Cyperus esculentus var. esculentus L. – accepted – yellow nutsedge, chufa flatsedge
  Cyperus flavescens L. – accepted – pale flatsedge, yellow flatsedge
  Cyperus fuscus L. – accepted – brown flatsedge
  Cyperus haspan L. – accepted – haspan flatsedge
  Cyperus iria L. – accepted – ricefield flatsedge
  Cyperus laevigatus L. – accepted – smooth nutgrass, smooth flatsedge
  Cyperus ligularis L. – accepted – Alabama swamp flatsedge
  Cyperus monostachyos L. – not accepted
  Cyperus odoratus L. – accepted – rusty flat sedge, fragrant flatsedge
  Cyperus papyrus L. – accepted – papyrus
  Cyperus pumilus L. – accepted – low flatsedge
  Cyperus rotundus L. – accepted – chaguan humatag, cocograss, kili'o'opu, pakopako, purple nutsedge, nutgrass
  Cyperus squarrosus L. – accepted – bearded flatsedge, awned flat sedge, bearded nutgrass
  Cyperus strigosus L. – accepted – stawcolored flatsedge, strawcolored nutgrass, strawcolor flatsedge, strawcolor nutgrass, strawcolored flatsedge
  Cypripedium L. – accepted – lady's slipper
  Cypripedium calceolus L. – accepted
  Cyrilla racemiflora L. – accepted – swamp cyrilla, swamp titi
  Cyrilla racemiflora var. racemiflora L. – not accepted
  Cytiscus L. – not accepted
  Cytiscus monspessulanus L. – not accepted
  Cytisus hirsutus L. – not accepted
  Cytisus monspessulanus L. – not accepted – French broom
  Cytisus nigricans L. – accepted
  Cytisus sessilifolius L. – not accepted
  Cytisus supinus L. – not accepted
  Dactylis L. – accepted – orchardgrass
  Dactylis cynosuroides L. – not accepted
  Dactylis glomerata L. – accepted – cocksfoot, orchardgrass, orchard grass
  Dactylis glomerata ssp. glomerata L. – accepted – orchardgrass
  Dactylis glomerata var. glomerata L. – not accepted
  Dactylus L. – not accepted
  Dalea L. – accepted – prairie clover, prairieclovers, prairieclover
  Dalechampia L. – accepted
  Dalechampia scandens L. – accepted – spurgecreeper
  Dalibarda L. – accepted
  Dalibarda repens L. – not accepted – robin runaway
  Daphne L. – accepted
  Daphne cneorum L. – accepted
  Daphne laureola L. – accepted – spurge-laurel, spurgelaurel, February daphne
  Daphne mezereum L. – accepted – paradise-plant, mezereon
  Datisca L. – accepted
  Datisca cannabina L. – accepted – akalbir
  Datisca hirta L. – not accepted
  Datura L. – accepted – jimsonweed, datura
  Datura arborea L. – not accepted
  Datura metel L. – accepted
  Datura stramonium L. – accepted – jimsonweed, Jamestown weed, mad apple, moonflower, stinkwort, thorn apple
  Datura stramonium var. stramonium L. – not accepted – jimsonweed
  Datura tatula L. – not accepted
  Daucus L. – accepted – carrot, wild carrot
  Daucus carota L. – accepted – bird's nest, wild carrot, Queen Anne's lace
  Daucus carota ssp. carota L. – not accepted – wild carrot, bird's nest, Queen Anne's lace
  Decumaria L. – accepted
  Decumaria barbara L. – accepted – woodvamp
  Delphinium L. – accepted – larkspur
  Delphinium ajacis L. – not accepted
  Delphinium ambiguum L. – not accepted
  Delphinium consolida L. – not accepted
  Delphinium elatum L. – accepted – candle larkspur
  Delphinium grandiflorum L. – accepted – Siberian larkspur
  Dentaria L. – not accepted
  Dialium L. – accepted
  Dianthera americana L. – not accepted
  Dianthera comata L. – not accepted
  Dianthus L. – accepted – pink
  Dianthus arenarius L. – accepted – Finnish pink, sand pink
  Dianthus armeria L. – accepted – Deptford pink
  Dianthus armeria ssp. armeria L. – accepted – grass pink, Deptford pink
  Dianthus barbatus L. – accepted – sweetwilliam
  Dianthus barbatus ssp. barbatus L. – accepted – sweetwilliam
  Dianthus carthusianorum L. – accepted – clusterhead
  Dianthus caryophyllus L. – accepted – carnation
  Dianthus chinensis L. – accepted – rainbow pink
  Dianthus deltoides L. – accepted – maiden pink
  Dianthus deltoides ssp. deltoides L. – accepted – meadow pink, maiden pink
  Dianthus plumarius L. – accepted – laced pink, cottage pink, garden pink, feathered pink
  Dianthus prolifer L. – not accepted
  Dianthus superbus L. – accepted – fringed pink
  Diapensia L. – accepted – pincushion plant
  Diapensia lapponica L. – accepted – pincushion plant
  Diapensia lapponica var. lapponica L. – not accepted – pincushion plant
  Dictamnus L. – accepted
  Dictamnus albus L. – accepted – gasplant
  Digitalis L. – accepted – foxglove
  Digitalis ferruginea L. – accepted – rusty foxglove
  Digitalis lutea L. – accepted – straw foxglove
  Digitalis purpurea L. – accepted – purple foxglove
  Digitalis purpurea ssp. purpurea L. – accepted – purple foxglove
  Digitalis purpurea var. purpurea L. – not accepted – purple foxglove
  Dillenia L. – accepted
  Dillenia indica L. – accepted – chulta
  Diodia L. – accepted – buttonweed
  Diodia virginiana L. – accepted – Virginia buttonweed
  Diodia virginiana var. virginiana L. – accepted – Virginia buttonweed
  Dioscorea L. – accepted – yam
  Dioscorea alata L. – accepted – winged yam, water yam
  Dioscorea bulbifera L. – accepted – potato yam, aerial yam, air potato, bitter yam, air yam
  Dioscorea oppositifolia L. – accepted
  Dioscorea pentaphylla L. – accepted – fiveleaf yam
  Dioscorea villosa L. – accepted – wild yam
  Diospyros L. – accepted – persimmons
  Diospyros lotus L. – accepted – date plum
  Diospyros virginiana L. – accepted – eastern persimmon, common persimmon
  Dipsacus L. – accepted – teasel
  Dipsacus fullonum L. – accepted – venuscup teasle, common teasel, teasel, Fuller's teasel
  Dipsacus fullonum ssp. fullonum L. – not accepted – Fuller's teasel, common teasel, teasel
  Dipsacus laciniatus L. – accepted – cutleaf teasel
  Dirca L. – accepted – leatherwood
  Dirca palustris L. – accepted – moosewood, eastern leatherwood, wicopy, bois de plomb, dirca des marais
  Dodecatheon L. – not accepted – shootingstar
  Dodecatheon meadia L. – not accepted – pride of Ohio, common shootingstar
  Dodecatheon meadia ssp. meadia L. – not accepted – pride of Ohio, darkthroat shootingstar
  Dodecatheon meadia var. meadia L. – not accepted – pride of Ohio
  Dolichos L. – accepted
  Dolichos biflorus L. – not accepted
  Dolichos ensiformis L. – not accepted
  Dolichos lablab L. – not accepted
  Dolichos lignosus L. – not accepted
  Dolichos minimus L. – not accepted
  Dolichos sesquipedalis L. – not accepted
  Dolichos soja L. – not accepted
  Dolichos trilobus L. – accepted
  Doronicum L. – accepted – false leopardbane
  Doronicum paralianches L. – not accepted
  Doronicum pardalianches L. – accepted – great false leopardbane
  Doronicum plantagineum L. – accepted – plantain false leopardbane
  Dorstenia L. – accepted
  Dorstenia contrajerva L. – accepted – tusilla
  Draba L. – accepted – draves, whitlowgrass
  Draba alpina L. – accepted – alpine draba
  Draba incana L. – accepted – twisted draba
  Draba incana var. incana L. – not accepted – twisted whitlowgrass
  Draba nemorosa L. – accepted – woodland whitlowgrass, woods draba, woodland draba
  Draba nemorosa var. nemorosa L. – not accepted – woodland whitlowgrass
  Draba verna L. – accepted – spring whitlowgrass, spring draba
  Dracaena L. – accepted – dracaena
  Dracocephalum L. – accepted – dragonhead
  Dracocephalum moldavica L. – accepted – Moldavian dragonhead
  Dracocephalum peltatum L. – not accepted
  Dracocephalum thymiflorum L. – accepted – thyme-leaf dragonhead, thymeleaf dragonhead
  Dracocephalum virginianum L. – not accepted
  Dracontium L. – accepted
  Dracontium polyphyllum L. – accepted – guapa
  Drosera L. – accepted – sundew, catch-fly, dew-threads, rossolis, droséra
  Drosera capensis L. – accepted – Cape sundew
  Drosera longifolia L. – not accepted
  Drosera rotundifolia L. – accepted – roundleaf sundew, droséra à feuilles rondes
  Drosera rotundifolia var. rotundifolia L. – not accepted – roundleaf sundew
  Dryas L. – accepted – mountain-avens
  Dryas octopetala L. – accepted – eightpetal mountain-avens
  Dryas octopetala ssp. octopetala L. – not accepted – eightpetal mountain-avens
  Dryas octopetala ssp. octopetala var. octopetala L. – not accepted – eightpetal mountain-avens
  Dryas octopetala ssp. punctata var. punctata L. – not accepted
  Dryas octopetala var. octopetala L. – not accepted – eightpetal mountain-avens
  Dryas pentapetala L. – not accepted
  Duranta L. – accepted
  Duranta erecta L. – accepted – golden dewdrops
  Duranta repens L. – not accepted
  Ebenus L. – accepted
  Echinops L. – accepted – globethistle
  Echinops fruticosa L. – not accepted
  Echinops fruticosus L. – not accepted
  Echinops rito L. – not accepted – southern globethistle
  Echinops rito ssp. rito L. – not accepted
  Echinops ritro L. – accepted – southern globethistle
  Echinops ritro ssp. ritro L. – accepted
  Echinops ritro var. ritro L. – not accepted
  Echinops sphaerocephalus L. – accepted – great globethistle
  Echites scholaris L. – not accepted
  Echium L. – accepted – viper's bugloss
  Echium creticum L. – accepted – Cretan vipersbugloss, Cretan viper's bugloss
  Echium italicum L. – accepted – Italian vipersbugloss, Italian viper's bugloss, Italian bugloss
  Echium lusitanicum L. – accepted – violet-vein viper's bugloss
  Echium lycopsis L. – not accepted
  Echium plantagineum L. – accepted – salvation jane
  Echium vulgare L. – accepted – blueweed, common vipersbugloss, common echium, common viper's bugloss
  Eclipta L. – accepted – eclipta
  Eclipta erecta L. – not accepted
  Eclipta punctata L. – not accepted
  Elaeagnus L. – accepted – silverberry, oleaster
  Elaeagnus angustifolia L. – accepted – Russian olive, Russian-olive, Trebizond-date, oleaster
  Elaeagnus orientalis L. – not accepted – Oriental olive
  Elaeocarpus L. – accepted
  Elatine L. – accepted – waterwort
  Elatine hydropiper L. – accepted
  Elephantopus L. – accepted – elephantsfoot
  Elephantopus scaber L. – accepted
  Elephantopus tomentosus L. – accepted – devil's grandmother, hairy elephantfoot
  Ellisia L. – accepted
  Elymus L. – accepted – wildrye
  Elymus arenarius L. – not accepted
  Elymus canadensis L. – accepted – Canada wildrye
  Elymus canadensis f. canadensis L. – not accepted
  Elymus canadensis ssp. canadensis L. – not accepted
  Elymus canadensis var. canadensis L. – accepted – Canada wildrye
  Elymus caput-medusae L. – not accepted
  Elymus hystrix L. – accepted – eastern bottlebrush grass, eastern bottle-brush grass
  Elymus hystrix f. hystrix L. – not accepted
  Elymus hystrix var. hystrix L. – accepted – eastern bottlebrush grass, eastern bottle-brush grass
  Elymus philadelphicus L. – not accepted
  Elymus sibiricus L. – accepted – Siberian wildrye
  Elymus virginicus L. – accepted – Virginia wild rye, Virginia wildrye
  Elymus virginicus f. virginicus L. – not accepted
  Elymus virginicus var. virginicus L. – accepted – Virginia wildrye, Virginia wild rye
  Empetrum L. – accepted – crowberry
  Empetrum nigrum L. – accepted – black crowberry
  Empetrum nigrum ssp. nigrum L. – not accepted
  Ephedra L. – accepted – Mormon tea, ephedra, jointfir
  Ephedra distachya L. – accepted – sea-grape, jointfir
  Epidendrum L. – accepted – star orchid
  Epidendrum ciliare L. – accepted – Epidendrum ciliado, fringed star orchid
  Epidendrum cochleatum L. – not accepted
  Epidendrum cucullatum L. – not accepted
  Epidendrum nodosum L. – not accepted
  Epigaea L. – accepted – trailing arbutus
  Epigaea repens L. – accepted – ground-laurel, mayflower, trailing arbutus
  Epilobium L. – accepted – willow weed, willowweed, willowherb
  Epilobium alpinum L. – not accepted
  Epilobium angustifolium L. – not accepted – fireweed, blooming sally, willowherb, rosebay willowherb, great willowherb, French-willow
  Epilobium angustifolium ssp. angustifolium L. – not accepted – fireweed
  Epilobium hirsutum L. – accepted – hairy willow herb, codlins and cream
  Epilobium latifolium L. – not accepted – dwarf fireweed
  Epilobium montanum L. – accepted
  Epilobium palustre L. – accepted – marsh willowweed, marsh willowherb
  Epimedium L. – accepted
  Equisetum L. – accepted – scouring rush, prêle, scouringrush, horsetail
  Equisetum (Equisetum) L. – accepted
  Equisetum arvense L. – accepted – prêle des champs, common horsetail, field horsetail, scouringrush, western horsetail
  Equisetum fluviatile L. – accepted – water horsetail, prêle fluviatile, pipes, river horsetail
  Equisetum giganteum L. – accepted – giant horsetail
  Equisetum hyemale L. – accepted – horsetail, scouring horsetail, scouringrush, tall scouring-rush, western scouringrush, prêle d'hiver, scouringrush horsetail
  Equisetum limosum L. – not accepted
  Equisetum palustre L. – accepted – prêle des marais, marsh horsetail
  Equisetum sylvaticum L. – accepted – woodland horsetail, prêle des bois
  Eranthemum L. – accepted
  Erica L. – accepted – heath
  Erica arborea L. – accepted – briar root, tree heath
  Erica cinerea L. – accepted – gray heath, bell heather, Scotch heath
  Erica tetralix L. – accepted – crossleaf heath
  Erica vagans L. – accepted – Cornish heath
  Erica vulgaris L. – not accepted
  Erigeron L. – accepted – fleabane, vergerettes, daisy
  Erigeron acris L. – accepted – bitter fleabane, bitter daisy, blue fleabane
  Erigeron acris ssp. acris L. – not accepted
  Erigeron acris ssp. acris var. acris L. – not accepted
  Erigeron acris var. acris L. – accepted
  Erigeron alpinus L. – accepted
  Erigeron bonariensis L. – not accepted
  Erigeron canadensis L. – not accepted
  Erigeron jamaicensis L. – accepted – Jamaican fleabane
  Erigeron philadelphicus L. – accepted – Philadelphia fleabane, Philadelphia daisy
  Erigeron philadelphicus var. philadelphicus L. – accepted – Philadelphia fleabane, Philadelphia daisy
  Erigeron uniflorus L. – accepted – oneflower fleabane
  Erigeron uniflorus var. uniflorus L. – accepted – oneflower fleabane
  Erinus L. – accepted
  Erinus alpinus L. – accepted – liver balsam, alpine balsam
  Eriocaulon L. – accepted – pipewort
  Eriocaulon decangulare L. – accepted – tenangle pipewort
  Eriocaulon decangulare var. decangulare L. – not accepted – tenangle pipewort
  Eriophorum L. – accepted – cottongrass
  Eriophorum alpinum L. – not accepted – alpine cottongrass
  Eriophorum vaginatum L. – accepted – tussock cottongrass
  Eriophorum vaginatum var. vaginatum L. – not accepted – tussock cottongrass
  Eriophorum virginicum L. – accepted – tawny cottongrass
  Erithalis fruticosa L. – accepted – blacktorch
  Ervum ervilia L. – not accepted
  Ervum lens L. – not accepted
  Eryngium L. – accepted – eryngo
  Eryngium amethystinum L. – accepted – amethyst eryngo
  Eryngium aquaticum L. – accepted – rattlesnakemaster
  Eryngium aquaticum var. aquaticum L. – accepted – rattlesnakemaster
  Eryngium campestre L. – accepted – field eryngo
  Eryngium foetidum L. – accepted – spiritweed
  Eryngium maritimum L. – accepted – seaside eryngo
  Eryngium planum L. – accepted – plains eryngo
  Erysimum L. – accepted – wallflower
  Erysimum alliaria L. – not accepted
  Erysimum cheiranthoides L. – accepted – wallflower mustard, wormseed mustard, treacle wallflower, worm-seed wallflower, wormseed wallflower
  Erysimum cheiranthoides var. cheiranthoides L. – not accepted
  Erysimum hieraciifolium L. – accepted – European wallflower
  Erysimum hieracilifolium L. – not accepted
  Erysimum officinale L. – not accepted
  Erysimum repandum L. – accepted – repand wallflower, spreading wallflower
  Erythrina L. – accepted – coraltrees, koraalbome
  Erythrina corallodendron L. – accepted – coral erythrina
  Erythrina corallodendron var. corallodendron L. – accepted
  Erythrina corallodendrum var. corallodendrum L. – not accepted
  Erythrina crista-galli L. – accepted – cockspur coral tree, crybabytree
  Erythrina herbacea L. – accepted – redcardinal, eastern coralbean
  Erythrina variegata L. – accepted – tiger's claw
  Erythronium L. – accepted – fawnlily
  Erythroxylum areolatum L. – accepted – swamp-redwood
  Ethulia sparganophora L. – not accepted
  Eugenia L. – accepted – eugenias, stoppers
  Eugenia jambos L. – not accepted
  Eugenia jamboscensis L. – not accepted
  Eugenia malaccensis L. – not accepted
  Eugenia uniflora L. – accepted – pitanga, Suriname cherry
  Euonymus L. – accepted – burningbush, spindletree
  Euonymus americana L. – not accepted – strawberry bush, strawberrybush
  Euonymus americanus L. – accepted – strawberry bush, hearts-bustin'-with-love, bursting-heart
  Euonymus europaea L. – not accepted – European spindletree
  Euonymus europaeus L. – accepted – European spindletree, spindletree
  Eupatorium L. – accepted – thoroughwort
  Eupatorium album L. – accepted – white thoroughwort
  Eupatorium album var. album L. – accepted – white thoroughwort
  Eupatorium altissimum L. – accepted – tall thoroughwort, tall joepyeweed
  Eupatorium aromaticum L. – not accepted
  Eupatorium cannabinum L. – accepted – hemp agrimony
  Eupatorium coelestinum L. – not accepted – blue mistflower
  Eupatorium hyssopifolium L. – accepted – hyssopleaf thoroughwort
  Eupatorium hyssopifolium var. hyssopifolium L. – accepted – hyssopleaf thoroughwort
  Eupatorium ivifolium L. – not accepted – ivyleaf thoroughwort
  Eupatorium macrophyllum L. – not accepted – largeleaf thoroughwort
  Eupatorium maculatum L. – not accepted – spotted joepyeweed, spotted joe-pye-weed
  Eupatorium maculatum var. maculatum L. – not accepted – spotted joepyeweed
  Eupatorium odoratum L. – not accepted – Jack in the bush
  Eupatorium perfoliatum L. – accepted – common boneset, Chapman's thoroughwort, boneset
  Eupatorium perfoliatum var. perfoliatum L. – not accepted – common boneset
  Eupatorium purpureum L. – not accepted – sweetscented joepyeweed
  Eupatorium purpureum var. purpureum L. – not accepted – sweetscented joepyeweed
  Eupatorium rotundifolium L. – accepted – roundleaf thoroughwort, roundleaf eupatorium
  Eupatorium rotundifolium var. rotundifolium L. – accepted – roundleaf thoroughwort
  Eupatorium sessilifolium L. – accepted – upland boneset
  Eupatorium sessilifolium var. sessilifolium L. – not accepted – upland boneset
  Eupatorium trifoliatum L. – not accepted
  Euphorbia L. – accepted – spurge
  Euphorbia aleppica L. – accepted
  Euphorbia amygdaloides L. – accepted
  Euphorbia amygdaloides ssp. amygdaloides L. – accepted
  Euphorbia antiquorum L. – accepted
  Euphorbia apios L. – accepted
  Euphorbia canariensis L. – accepted
  Euphorbia canescens L. – not accepted
  Euphorbia caput-medusae L. – accepted
  Euphorbia cereiformis L. – accepted
  Euphorbia chamaesyce L. – accepted
  Euphorbia characias L. – accepted – Albanian spurge
  Euphorbia characias ssp. characias L. – accepted
  Euphorbia corallioides L. – accepted
  Euphorbia corollata L. – accepted – floweringspurge euphorbia, flowering spurge
  Euphorbia cotinifolia L. – accepted – Mexican shrubby spurge
  Euphorbia cyparissias L. – accepted – cypress spurge, graveyard spurge
  Euphorbia dendroides L. – accepted – tree spurge
  Euphorbia dulcis L. – accepted
  Euphorbia epithymoides L. – accepted – cushion spurge
  Euphorbia esula L. – accepted – spurge, wolf's milk, wolf's-milk, leafy spurge
  Euphorbia esula ssp. esula L. – accepted
  Euphorbia esula var. esula L. – accepted – spurge, wolf's milk, wolf's-milk, leafy spurge
  Euphorbia exigua L. – accepted – dwarf spurge, ésula meno, hierbecilla traidora, small spurge
  Euphorbia exigua ssp. exigua L. – accepted
  Euphorbia exigua var. acuta L. – not accepted
  Euphorbia exigua var. retusa L. – not accepted
  Euphorbia falcata L. – accepted – sickle spurge
  Euphorbia falcata ssp. falcata L. – accepted
  Euphorbia falcata var. falcata L. – accepted
  Euphorbia helioscopia L. – accepted – madwoman's milk, summer spurge, sun spurge, wartweed
  Euphorbia helioscopia ssp. helioscopia L. – accepted
  Euphorbia heptagona L. – accepted
  Euphorbia heterophylla L. – accepted – Mexican fireplant, painted euphorbia
  Euphorbia hirsuta L. – accepted
  Euphorbia hirta L. – accepted – pillpod sandmat, pillpod spurge, asthma spurge
  Euphorbia hyberna L. – accepted
  Euphorbia hyberna ssp. hyberna L. – accepted
  Euphorbia hypericifolia L. – accepted – graceful sandmat
  Euphorbia hyssopifolia L. – accepted – hyssopleaf sandmat
  Euphorbia ipecacuanhae L. – accepted – American ipecac, Carolina ipecac
  Euphorbia lathyris L. – accepted – moleplant, cañamón purgante, gopher plant, caper spurge
  Euphorbia lathyrus L. – not accepted
  Euphorbia maculata L. – accepted – milk purslane, prostrate spurge, spotted spurge, spotted sandmat
  Euphorbia mammillaris L. – accepted
  Euphorbia mauritanica L. – accepted
  Euphorbia myrsinites L. – accepted – myrtle spurge, donkey tail, blue spurge, creeping spurge
  Euphorbia myrtillifolia L. – accepted
  Euphorbia neriifolia L. – accepted – Indian spurgetree
  Euphorbia ocymoidea L. – accepted
  Euphorbia officinarum L. – accepted
  Euphorbia officinarum ssp. officinarum L. – accepted
  Euphorbia orientalis L. – accepted
  Euphorbia origanoides L. – accepted
  Euphorbia palustris L. – accepted – marsh spurge
  Euphorbia paralias L. – accepted – sea spurge
  Euphorbia parviflora L. – accepted
  Euphorbia peplis L. – accepted
  Euphorbia peplus L. – accepted – petty spurge
  Euphorbia peplus var. peplus L. – accepted
  Euphorbia pilosa L. – accepted
  Euphorbia pilulifera L. – not accepted
  Euphorbia pinea L. – not accepted
  Euphorbia pithyusa L. – accepted
  Euphorbia pithyusa ssp. pithyusa L. – accepted
  Euphorbia platyphylla L. – not accepted
  Euphorbia platyphyllos L. – accepted – broadleaf spurge
  Euphorbia platyphyllos ssp. platyphyllos L. – accepted
  Euphorbia polygonifolia L. – accepted – seaside sandmat
  Euphorbia portlandica L. – accepted
  Euphorbia portulacoides L. – accepted
  Euphorbia portulacoides ssp. portulacoides L. – accepted
  Euphorbia segetalis L. – accepted – grainfield spurge
  Euphorbia segetalis var. segetalis L. – accepted
  Euphorbia serrata L. – accepted – serrate spurge, toothed spurge, saw-toothed spurge
  Euphorbia spinosa L. – accepted
  Euphorbia spinosa ssp. spinosa L. – accepted
  Euphorbia stricta L. – accepted
  Euphorbia sylvatica L. – not accepted
  Euphorbia terracina L. – accepted – Geraldton carnation weed, Terracina spurge, carnation spurge
  Euphorbia thymifolia L. – accepted – gulf sandmat
  Euphorbia tirucalli L. – accepted – Indiantree spurge
  Euphorbia tithymaloides L. – accepted – redbird flower
  Euphorbia tithymaloides ssp. tithymaloides L. – accepted – redbird flower, Pedilanthus
  Euphorbia tithymaloides var. myrtifolia L. – not accepted
  Euphorbia tithymaloides var. padifolia L. – not accepted
  Euphorbia tuberosa L. – accepted
  Euphorbia verrucosa L. – accepted
  Euphrasia L. – accepted – eyebright
  Euphrasia officinalis L. – accepted
  Evolvulus L. – accepted – dwarf morningglory, dwarf morning-glory
  Evolvulus linifolius L. – not accepted
  Excoecaria L. – accepted
  Excoecaria agallocha L. – accepted
  Fagonia L. – accepted – fagonbush
  Fagus L. – accepted – beech
  Fagus sylvatica L. – accepted – European beech
  Ferula L. – accepted
  Ferula assa-foetida L. – accepted – asafetida, asafoetida
  Festuca L. – accepted – fescue
  Festuca amethystina L. – accepted
  Festuca barbata L. – not accepted
  Festuca bromoides L. – not accepted
  Festuca cristata L. – not accepted
  Festuca decumbens L. – not accepted
  Festuca duriuscula L. – not accepted
  Festuca elatior L. – not accepted
  Festuca elatior f. elatior L. – not accepted
  Festuca fluitans L. – not accepted
  Festuca fusca L. – not accepted
  Festuca myuros L. – not accepted
  Festuca myuros var. myuros L. – not accepted
  Festuca ovina L. – accepted – sheep fescue
  Festuca ovina f. ovina L. – not accepted
  Festuca ovina ssp. ovina L. – not accepted
  Festuca ovina var. ovina L. – not accepted – sheep fescue
  Festuca ovina var. vivipara L. – not accepted
  Festuca phoenicoides L. – not accepted
  Festuca reptatrix L. – not accepted
  Festuca rubra L. – accepted – red fescue, ravine fescue
  Festuca rubra f. rubra L. – not accepted
  Festuca rubra ssp. rubra L. – accepted – red fescue
  Festuca rubra var. rubra L. – not accepted
  Fevillea L. – accepted
  Fevillea cordifolia L. – accepted – antidote caccoon
  Ficus L. – accepted – fig
  Ficus L. – not accepted
  Ficus benghalensis L. – accepted – Indian banyan
  Ficus benjamina L. – accepted – weeping fig
  Ficus carica L. – accepted – fiku, piku, common fig, edible fig
  Ficus perforata L. – not accepted
  Ficus pumila L. – accepted – climbingfig
  Ficus racemosa L. – accepted – clustertree
  Ficus religiosa L. – accepted – peepul tree
  Ficus sycomorus L. – accepted – sycamore fig
  Ficus trigonata L. – accepted – jaguey blanco
  Filago L. – accepted – cottonrose
  Filago arvensis L. – not accepted – field cottonrose
  Filago gallica L. – not accepted – narrowleaf cottonrose
  Filago pyramidata L. – accepted – broadleaf cottonrose
  Filago pyramidata var. pyramidata L. – accepted – cottonrose, filzkraut
  Flagellaria L. – accepted
  Flagellaria indica L. – accepted
  Fothergilla L. – accepted – witchalder
  Fothergilla gardenii L. – accepted – dwarf witch-alder
  Fragaria L. – accepted – strawberry
  Fragaria sterilis L. – not accepted
  Fragaria vesca L. – accepted – woodland strawberry
  Fragaria vesca ssp. vesca L. – accepted – woodland strawberry
  Frankenia L. – accepted – seaheath
  Frankenia pulverulenta L. – accepted – European sea-heath, European seaheath, wisp-weed
  Fraxinus L. – accepted – ash
  Fraxinus americana L. – accepted – white ash
  Fraxinus excelsior L. – accepted – European ash
  Fraxinus ornus L. – accepted – flowering ash
  Fritillaria L. – accepted – mission bells, fritillary
  Fritillaria imperialis L. – accepted – imperial fritillary
  Fritillaria meleagris L. – accepted – chequered lily
  Fuchsia L. – accepted – fuchsia
  Fumaria L. – accepted – fumitory
  Fumaria capreolata L. – accepted – white ramping fumitory
  Fumaria officinalis L. – accepted – drug fumitory
  Fumaria officinalis ssp. officinalis L. – not accepted – drug fumitory
  Galanthus L. – accepted – snowdrop
  Galanthus nivalis L. – accepted – snowdrop
  Galega L. – accepted – professor-weed
  Galega officinalis L. – accepted – professor-weed, professorweed, goat's rue, goatsrue
  Galenia L. – accepted – galenia
  Galeopsis L. – not accepted
  Galeopsis L. – accepted – hempnettle
  Galeopsis ladanum L. – accepted – red hempnettle
  Galeopsis ladanum var. ladanum L. – accepted – red hempnettle
  Galeopsis tetrahit L. – accepted – bristlestem hempnettle, brittle-stem hemp-nettle, brittlestem hempnettle
  Galeopsis tetrahit var. tetrahit L. – accepted – brittlestem hempnettle
  Galium L. – accepted – gaillet, bedstraw
  Galium aparine L. – accepted – bedstraw, cleavers, cleaverwort, scarthgrass, white hedge, catchweed bedstraw, goose grass, sticky-willy, stickywilly
  Galium aristatum L. – accepted – awned bedstraw
  Galium bermudense L. – accepted
  Galium boreale L. – accepted – northern bedstraw
  Galium boreale var. boreale L. – not accepted
  Galium glaucum L. – accepted – waxy bedstraw
  Galium mollugo L. – accepted – false baby's breath
  Galium palustre L. – accepted – common marsh bedstraw
  Galium parisiense L. – accepted – wall bedstraw
  Galium purpureum L. – not accepted
  Galium rubioides L. – accepted – European bedstraw
  Galium saxatile L. – accepted – heath bedstraw
  Galium spurium L. – not accepted – Marin County bedstraw
  Galium sylvaticum L. – accepted – scotchmist
  Galium tinctorium L. – accepted – dye bedstraw, stiff marsh bedstraw
  Galium tinctorium var. tinctorium L. – not accepted
  Galium trifidum L. – accepted – three-petal bedstraw, small bedstraw, threepetal bedstraw
  Galium trifidum ssp. trifidum L. – accepted – threepetal bedstraw
  Galium uliginosum L. – accepted – fen bedstraw
  Galium verum L. – accepted – Yellow Spring bedstraw
  Galium verum var. verum L. – accepted – Yellow Spring bedstraw
  Garcinia L. – accepted – saptree
  Garcinia mangostana L. – accepted – mangosteen
  Gardenia florida L. – not accepted
  Gaultheria L. – accepted – snowberry, wintergreen
  Gaultheria procumbens L. – accepted – checkerberry, eastern wintergreen, eastern teaberry
  Gaura L. – not accepted – beeblossom
  Gaura biennis L. – not accepted – biennial beeblossom
  Genipa L. – accepted
  Genipa americana L. – accepted – jagua
  Genista L. – accepted – broom
  Genista canariensis L. – accepted – Canary broom
  Genista linifolia L. – accepted – Mediterranean broom
  Genista tinctoria L. – accepted – dyer's greenweed, woadwaxen, woodwaxen, dyer's broom
  Genista tridentata L. – accepted
  Gentiana L. – accepted – gentian
  Gentiana acaulis L. – accepted – gentian
  Gentiana aurea L. – not accepted
  Gentiana autumnalis L. – accepted – pine barren gentian
  Gentiana cruciata L. – accepted – star gentian
  Gentiana lutea L. – accepted – yellow gentian
  Gentiana nivalis L. – accepted – snow gentian
  Gentiana quinquefolia L. – not accepted
  Gentiana saponaria L. – accepted – harvestbells, moss gentian
  Gentiana saponaria var. saponaria L. – accepted – harvestbells
  Gentiana verna L. – accepted – spring gentian
  Gentiana verticillata L. – not accepted
  Gentiana villosa L. – accepted – striped gentian
  Geranium L. – accepted – geranium
  Geranium carolinianum L. – accepted – Carolina crane's-bill, Carolina geranium
  Geranium carolinianum var. carolinianum L. – accepted – Carolina geranium
  Geranium columbinum L. – accepted – longstalk cranesbill
  Geranium dissectum L. – accepted – cutleaf geranium
  Geranium lucidium L. – not accepted
  Geranium lucidum L. – accepted – shining geranium
  Geranium maculatum L. – accepted – wild crane's-bill, spotted crane's-bill, spotted geranium
  Geranium molle L. – accepted – awnless geranium, dovefoot geranium
  Geranium pratense L. – accepted – meadow geranium
  Geranium pusillum L. – accepted – small-flower crane's-bill, small geranium
  Geranium robertianum L. – accepted – Robert's geranium
  Geranium robertianum ssp. robertianum L. – accepted – Robert's geranium
  Geranium rotundifolium L. – accepted – roundleaf geranium
  Geranium sanguineum L. – accepted – bloody geranium
  Geranium sibiricum L. – accepted – Siberian geranium
  Geranium striatum L. – not accepted
  Geranium sylvaticum L. – accepted – woodland geranium
  Geranium versicolor L. – accepted – veiny geranium
  Gerardia flava L. – not accepted
  Gerardia pedicularia L. – not accepted
  Gerardia purpurea L. – not accepted
  Gerardia tuberosa L. – not accepted
  Gesneria acaulis L. – accepted
  Gesneria acaulis var. acaulis L. – accepted
  Gesneria humilis L. – accepted
  Geum L. – accepted – avens
  Geum rivale L. – accepted – water avens, purple avens
  Geum urbanum L. – accepted – herb bennet
  Geum virginianum L. – accepted – cream avens
  Gingko L. – not accepted
  Gingkyo L. – not accepted
  Ginkgo L. – accepted – ginkgo
  Ginkgo biloba L. – accepted – maidenhair tree, common ginkgo
  Ginko L. – not accepted
  Ginkyo L. – not accepted
  Gisekia L. – accepted
  Gisekia pharnacioides L. – accepted – oldmaid
  Gladiolus L. – accepted – gladiolus
  Gladiolus communis L. – accepted – cornflag
  Gladiolus communis ssp. communis L. – not accepted – cornflag
  Gladiolus tristis L. – accepted – ever-flowering gladiolus
  Glaux L. – not accepted – milkwort
  Glaux maritima L. – not accepted – sea-milkwort
  Glaux maritima ssp. maritima L. – not accepted – sea-milkwort
  Glechoma L. – accepted
  Glechoma hederacea L. – accepted – creeping charlie, gill-over-the-ground, haymaids, groundivy, ground ivy
  Glechoma hederacea var. hederacea L. – not accepted – groundivy
  Glecoma L. – not accepted
  Glecoma hederacea L. – not accepted
  Gleditsia L. – accepted – locust, honeylocust
  Gleditsia triacanthos L. – accepted – honeylocust, honey-locust, common honeylocust, honey locust
  Glinus L. – accepted – sweetjuice, sweet juice
  Glinus latoides L. – not accepted
  Glinus lotoides L. – accepted – damascisa, lotus sweetjuice
  Gloriosa L. – accepted – flame lily
  Gloriosa superba L. – accepted – flame lily
  Gluta L. – accepted
  Gluta renghas L. – accepted – rengas
  Glycine abrus L. – not accepted
  Glycine apios L. – not accepted
  Glycine bracteata L. – not accepted
  Glycine comosa L. – not accepted
  Glycine javanica L. – not accepted
  Glycine subterranea L. – not accepted
  Glycine tomentosa L. – not accepted
  Glycyrrhiza L. – accepted – licorice
  Glycyrrhiza echinata L. – accepted – Chinese licorice, hedgehog liquorice, licorice, regaliz espinoso
  Glycyrrhiza glabra L. – accepted – cultivated licorice
  Gmelina L. – accepted
  Gmelina asiatica L. – accepted – Asian bushbeech
  Gnaphalium L. – accepted – cudweed
  Gnaphalium alpinum L. – not accepted
  Gnaphalium arvense L. – not accepted
  Gnaphalium dioicum L. – not accepted
  Gnaphalium luteoalbum L. – not accepted
  Gnaphalium margaritaceum L. – not accepted
  Gnaphalium obtusifolium L. – not accepted
  Gnaphalium obtusifolium var. obtusifolium L. – not accepted – rabbit tobacco
  Gnaphalium plantaginifolium L. – not accepted
  Gnaphalium purpureum L. – not accepted – catfoot, chafe weed, everlasting, purple cudweed, rabbit tobacco, spoonleaf purple everlasting
  Gnaphalium supinum L. – not accepted
  Gnaphalium sylvaticum L. – not accepted
  Gnaphalium uliginosum L. – accepted – marsh cudweed, low cudweed
  Gnaphalium virgatum L. – not accepted
  Gnetum L. – accepted – jointfir
  Gnetum gnemon L. – accepted – buko
  Gomphrena L. – accepted – globe amaranth
  Gomphrena brasiliana L. – not accepted
  Gomphrena globosa L. – accepted – common globe amaranth
  Gomphrena serrata L. – accepted – arrasa con todo
  Gomphrena sessilis L. – not accepted
  Gomphrena vermicularis L. – not accepted
  Gossypium L. – accepted – cotton
  Gossypium arboreum L. – accepted – tree cotton
  Gossypium barbadense L. – accepted – Creole cotton
  Gossypium herbaceum L. – accepted – Levant cotton
  Gossypium hirsutum L. – accepted – upland cotton, algodón
  Gossypium hirsutum var. hirsutum L. – not accepted – upland cotton
  Gossypium religiosum L. – not accepted
  Gratiola L. – accepted – hedge hyssop, hedgehyssop
  Gratiola dubia L. – not accepted
  Gratiola officinalis L. – accepted – hedgehyssop
  Gratiola virginiana L. – accepted – roundfruit hedgehyssop, Virginia hedgehyssop
  Gratiola virginiana var. virginiana L. – accepted – roundfruit hedgehyssop
  Grewia L. – accepted
  Grewia asiatica L. – accepted – phalsa
  Grewia occidentalis L. – accepted – crossberry
  Guaiacum L. – accepted – lignum-vitae
  Guaiacum officinale L. – accepted – lignum vitae, lignum-vitae
  Guaiacum sanctum L. – accepted – roughbark lignumvitae, holywood
  Guajacum L. – not accepted – lignum-vitae, lignumvitae
  Guajacum officinale L. – not accepted – lignum-vitae
  Guajacum sanctum L. – not accepted – holywood
  Guarea trichilioides L. – not accepted
  Guettarda L. – accepted
  Guettarda speciosa L. – accepted
  Guilandina L. – accepted
  Guilandina bonduc L. – accepted
  Gundelia L. – accepted – gundelia
  Gundelia tournefortii L. – accepted – Tournefort's gundelia
  Gunnera L. – accepted – gunnera
  Gypsophila L. – accepted – babysbreath, baby's-breath
  Gypsophila muralis L. – accepted – low babysbreath, low baby's-breath
  Gypsophila paniculata L. – accepted – bachelor's button, babysbreath gypsophila, babysbreath, perfoliate baby's breath, baby's breath
  Gypsophila paniculata var. paniculata L. – not accepted – baby's breath
  Gypsophila perfoliata L. – accepted – perfoliate babysbreath, perfoliate baby's-breath
  Gypsophila perfoliata var. perfoliata L. – not accepted – perfoliate baby's-breath, perfoliate babysbreath
  Gypsophila repens L. – accepted – creeping babysbreath, creeping baby's-breath
  Haematoxylum L. – accepted
  Haematoxylum campechianum L. – accepted – bloodwoodtree
  Halesia carolina L. – accepted – silverbell, Carolina silverbell
  Hamamelis L. – accepted – witchhazel
  Hamamelis virginiana L. – accepted – witch-hazel, witchhazel, American witchhazel
  Hedera L. – accepted – ivy
  Hedera helix L. – accepted – English ivy
  Hedera quinquefolia L. – not accepted
  Hedyotis L. – accepted – starviolet
  Hedyotis herbacea L. – not accepted
  Hedysarum L. – accepted – sweetvetch, sweet vetch
  Hedysarum alpinum L. – accepted – alpine sweetvetch
  Hedysarum coronarium L. – accepted – sulla
  Hedysarum flexuosum L. – accepted
  Hedysarum hamatum var. viscosum L. – not accepted – poorman's friend, viscid pencil-flower
  Hedysarum humile L. – accepted
  Hedysarum onobrychis L. – not accepted
  Hedysarum repens L. – not accepted
  Hedysarum spinosissimum L. – accepted
  Hedysarum violaceum L. – not accepted
  Helenium L. – accepted – sneezeweed
  Helenium autumnale L. – accepted – common sneezeweed, fall sneezeweed, mountain sneezeweed, bitterweed, false sunflower
  Helenium autumnale var. autumnale L. – not accepted – common sneezeweed
  Helianthus L. – accepted – sunflower
  Helianthus agustifolius L. – not accepted
  Helianthus angustifolius L. – accepted – swamp sunflower, swamp sneezeweed
  Helianthus annuus L. – accepted – common sunflower, sunflower, wild sunflower, annual sunflower
  Helianthus atrorubens L. – accepted – purpledisk sunflower
  Helianthus decapetalis L. – not accepted
  Helianthus decapetalus L. – accepted – thinleaf sunflower
  Helianthus divaricatus L. – accepted – woodland sunflower, hélianthe à feuilles étalées
  Helianthus giganteus L. – accepted – giant sunflower
  Helianthus laevis L. – not accepted
  Helianthus strumosus L. – accepted – paleleaf woodland sunflower
  Helianthus tuberosus L. – accepted – Jerusalem artichoke, girasole, Jerusalem sunflower, Jerusalem-artichoke
  Heliconia L. – accepted – heliconia
  Helicteres L. – accepted
  Heliocarpus L. – accepted
  Heliocarpus americanus L. – accepted
  Heliotropium L. – accepted – heliotrope
  Heliotropium arborescens L. – accepted – garden heliotrope
  Heliotropium curassavicum L. – accepted – quail plant, seaside heliotrope, salt heliotrope
  Heliotropium curassavicum var. curassavicum L. – accepted – salt heliotrope
  Heliotropium europaeum L. – accepted – European heliotrope
  Heliotropium fruticosum L. – not accepted – Key West heliotrope
  Heliotropium indicum L. – accepted – India heliotrope, Indian heliotrope
  Heliotropium parviflorum L. – not accepted
  Heliotropium peruvianum L. – not accepted
  Heliotropium supinum L. – accepted – dwarf heliotrope
  Helleborus L. – accepted – hellebore
  Helleborus foetidus L. – accepted – setterwort
  Helleborus hyemalis L. – not accepted
  Helleborus niger L. – accepted – black hellebore, Christmas-rose
  Helleborus viridis L. – accepted – green hellebore
  Helonias L. – accepted – helonias
  Helonias asphodeloides L. – not accepted
  Helonias bullata L. – accepted – swamp pink, swamppink
  Hemerocallis L. – accepted – daylily
  Hemerocallis lilioasphodelus L. – accepted – yellow daylily, lemon lily, lemon daylily
  Hemerocallis lilioasphodelus var. flava L. – not accepted
  Hemionitis L. – accepted
  Hemionitis palmata L. – accepted – starfern
  Heracleum L. – accepted – cow parsnip, cowparsnip
  Heracleum sibiricum L. – not accepted
  Heracleum sphondylium L. – accepted – eltrot
  Hermandia L. – not accepted
  Hermandia sonora L. – not accepted
  Hermannia L. – accepted – burstworts
  Hernandia L. – accepted
  Hernandia sonora L. – accepted – mago
  Herniaria L. – accepted – rupturewort
  Herniaria glabra L. – accepted – smooth rupturewort
  Herniaria hirsuta L. – accepted – hairy rupturewort
  Herniaria hirsuta ssp. hirsuta L. – not accepted – hairy rupturewort
  Herniaria hirsuta var. hirsuta L. – accepted – hairy rupturewort
  Hesperis L. – accepted – rocket
  Hesperis matronalis L. – accepted – dame's rocket, dames violet, mother-of-the-evening, dames rocket
  Heuchera L. – accepted – alumroot
  Heuchera americana L. – accepted – American alumroot, alumroot
  Heuchera americana var. americana L. – accepted – American alumroot
  Hibiscus L. – accepted – rosemallow, rose-mallow
  Hibiscus abelmoschus L. – not accepted
  Hibiscus cannabinus L. – accepted – brown Indianhemp
  Hibiscus clypeatus L. – accepted – Congo mahoe
  Hibiscus clypeatus ssp. clypeatus L. – accepted
  Hibiscus esculentus L. – not accepted
  Hibiscus malvaviscus L. – not accepted
  Hibiscus manihot L. – not accepted
  Hibiscus moscheutos L. – accepted – swamp rosemallow, crimsoneyed rosemallow, common rose-mallow
  Hibiscus moscheutos ssp. moscheutos L. – accepted – crimsoneyed rosemallow
  Hibiscus mutabilis L. – accepted – Dixie rosemallow, confederate-rose, changeable-rose
  Hibiscus palustris L. – not accepted
  Hibiscus pentacarpos L. – not accepted
  Hibiscus populneus L. – not accepted
  Hibiscus rosa-sinensis L. – accepted – Chinese hibiscus, shoe-black plant
  Hibiscus sabbariffa L. – not accepted
  Hibiscus sabdariffa L. – accepted – roselle
  Hibiscus simplex L. – not accepted
  Hibiscus spinifex L. – not accepted
  Hibiscus syriacus L. – accepted – shrub althea, althea, rose of Sharon, Korean hibiscus, Rose-of-Sharon
  Hibiscus tiliaceus L. – not accepted – mahoe, sea hibiscus
  Hibiscus trionum L. – accepted – flower-of-an-hour, bladder ketmia, rosemallow, Venice mallow, flower of an hour, ketmie trilobée
  Hibiscus vitifolius L. – not accepted – tropical rose mallow
  Hieracium L. – accepted – hawkweed
  Hieracium alpinum L. – accepted – alpine hawkweed
  Hieracium aurantiacum L. – accepted – orange hawkweed
  Hieracium gronovii L. – accepted – queendevil, Gronovis hawkweed
  Hieracium kalmii L. – not accepted – Kalm's hawkweed
  Hieracium kalmii var. kalmii L. – not accepted – Kalm's hawkweed
  Hieracium murorum L. – accepted – wall hawkweed
  Hieracium paniculatum L. – accepted – Allegheny hawkweed
  Hieracium pilosella L. – accepted – mouseear hawkweed
  Hieracium pilosella var. pilosella L. – not accepted – mouseear hawkweed
  Hieracium sabaudum L. – accepted – New England hawkweed
  Hieracium umbellatum L. – accepted – narrowleaf hawkweed, Canadian hawkweed, smooth hawkweed, Kalm's hawkweed, narrow-leaf hawkweed
  Hieracium unbellatum L. – not accepted
  Hieracium venosum L. – accepted – rattlesnakeweed
  Hieracium venosum var. venosum L. – not accepted – rattlesnakeweed
  Hippocratea L. – accepted
  Hippocratea volubilis L. – accepted – medicine vine
  Hippocrepis L. – accepted
  Hippocrepis comosa L. – accepted – horseshoe vetch
  Hippocrepis multisiliquosa L. – accepted
  Hippocrepis unisiliquosa L. – accepted
  Hippomane L. – accepted
  Hippomane mancinella L. – accepted – manchineel
  Hippophae L. – accepted – seabuckthorn, seaberry
  Hippophae rhamnoides L. – accepted – seaberry, seabuckthorn
  Hippuris L. – accepted – mare's-tail
  Hippuris vulgaris L. – accepted – common mare's-tail, common mare's tail
  Hirtella L. – accepted
  Hirtella americana L. – accepted
  Holcus L. – accepted – velvetgrass, velvet grass
  Holcus bicolor L. – not accepted
  Holcus halepensis L. – not accepted
  Holcus lanatus L. – accepted – velvetgrass, Yorkshire fog, common velvetgrass
  Holcus laxus L. – not accepted
  Holcus mollis L. – accepted – creeping velvetgrass
  Holcus odoratus L. – not accepted
  Holcus pertusus L. – not accepted
  Holcus saccharatus L. – not accepted
  Holcus sorghum L. – not accepted
  Holcus spicatus L. – not accepted
  Holcus striatus L. – not accepted
  Holosteum L. – accepted
  Holosteum cordata L. – not accepted
  Holosteum umbelatum L. – not accepted
  Holosteum umbellatum L. – accepted – jagged chickweed
  Holosteum umbellatum ssp. umbellatum L. – accepted – jagged chickweed
  Hordeum L. – accepted – barley
  Hordeum bulbosum L. – accepted – bulbous barley
  Hordeum distichon L. – not accepted
  Hordeum distichum L. – not accepted
  Hordeum hexastichon L. – not accepted
  Hordeum hexastichum L. – not accepted
  Hordeum jubatum L. – accepted – foxtail barley
  Hordeum jubatum ssp. jubatum L. – accepted – foxtail barley, fox-tail barley, bobtail barley
  Hordeum jubatum var. jubatum L. – not accepted
  Hordeum murinum L. – accepted – mouse barley, bulbous barley
  Hordeum murinum ssp. murinum L. – accepted – wall barley
  Hordeum nodosum L. – not accepted
  Hordeum vulgare L. – accepted – common barley, barley, cereal barley
  Hottonia L. – accepted
  Hottonia indica L. – not accepted
  Houstonia L. – accepted – bluet
  Houstonia caerulea L. – accepted – azure bluet
  Houstonia purpurea L. – accepted – Venus' pride, purple bluets
  Houstonia purpurea var. purpurea L. – accepted – Venus' pride
  Hudsonia L. – not accepted
  Hudsonia L. – accepted – goldenheather
  Hudsonia ericoides L. – accepted – pinebarren goldenheather, pine barren goldenheather
  Humulus L. – accepted – hop
  Humulus lupulus L. – accepted – common hops, hops, common hop
  Humulus lupulus var. lupulus L. – accepted – common hop
  Hura L. – accepted – sandbox tree
  Hura crepitans L. – accepted – sandbox tree
  Hyacinthus L. – accepted – hyacinth
  Hyacinthus botryoides L. – not accepted
  Hyacinthus orientalis L. – accepted – garden hyacinth
  Hydrangea L. – accepted – hydrangea
  Hydrangea arborescens L. – accepted – smooth hydrangea, wild hydrangea
  Hydrastis L. – accepted
  Hydrastis canadensis L. – accepted – goldenseal
  Hydrocharis L. – accepted
  Hydrocharis morsus-ranae L. – accepted – common frogbit
  Hydrocotyle L. – accepted
  Hydrocotyle americana L. – accepted – American marshpennywort
  Hydrocotyle asiatica L. – not accepted
  Hydrocotyle umbellata L. – accepted – umbrella pennyroyal, manyflower marshpennywort
  Hydrocotyle vulgaris L. – accepted
  Hydrolea L. – accepted – hydrolea, false fiddleleaf
  Hydrolea spinosa L. – accepted – spiny false fiddleleaf
  Hydrophyllum L. – accepted – waterleaf
  Hydrophyllum canadense L. – accepted – blunt-leaf waterleaf, bluntleaf waterleaf
  Hydrophyllum virginianum L. – accepted – Shawnee-salad, eastern waterleaf, Virginia waterleaf, Shawnee salad
  Hydrophyllum virginianum var. virginianum L. – accepted – eastern waterleaf
  Hymenaea L. – accepted
  Hymenaea courbaril L. – accepted – stinkingtoe
  Hyoscyamus L. – accepted – henbane
  Hyoscyamus albus L. – accepted – white henbane
  Hyoscyamus muticus L. – accepted – henbane
  Hyoscyamus niger L. – accepted – black henbane, henbane
  Hyoseris minima L. – not accepted
  Hyoseris virginica L. – not accepted
  Hypecoum L. – accepted
  Hypecoum pendulum L. – accepted – nodding hypecoum
  Hypericum L. – accepted – St. Johnswort
  Hypericum aegypticum L. – accepted
  Hypericum androsaemum L. – accepted – tutsan, sweet-amber
  Hypericum ascyron L. – accepted – great St. Johnswort
  Hypericum calycinum L. – accepted – Aaron's beard
  Hypericum canadense L. – accepted – lesser Canadian St. Johnswort
  Hypericum canariense L. – accepted – Canary Island St. Johnswort
  Hypericum coris L. – accepted
  Hypericum hircinum L. – accepted
  Hypericum humifusum L. – accepted – trailing St. Johnswort
  Hypericum kalmianum L. – accepted – kalm's st. john's-wort, millepertuis de Kalm, Kalm's St. Johnswort
  Hypericum mutilum L. – accepted – dwarf St. Johnswort
  Hypericum mutilum ssp. mutilum L. – accepted – dwarf St. Johnswort
  Hypericum perforatum L. – accepted – St. John's wort, common St. John's wort, Klamathweed, Klamath weed, St. Johnswort, common St. Johnswort
  Hypericum prolificum L. – accepted – shrubby St. Johnswort
  Hypericum pulchrum L. – accepted
  Hypericum setosum L. – accepted – hairy St. Johnswort
  Hypericum virginicum L. – not accepted
  Hypochaeris L. – accepted – cat's ear, catsear
  Hypochaeris glabra L. – accepted – smooth cat's ear, smooth catsear
  Hypochaeris radicata L. – accepted – hairy cat's ear, common cat's-ear, false dandelion, frogbit, gosmore, spotted catsear, hairy catsear
  Hypochoeris L. – not accepted – catsear
  Hypoxis L. – accepted – star-grass
  Hypoxis decumbens L. – not accepted
  Hypoxis sessilis L. – accepted – glossyseed yellow star-grass
  Hyssopus L. – accepted
  Hyssopus officinalis L. – accepted – hyssop
  Iberis L. – accepted – candytuft
  Iberis amara L. – accepted – annual candytuft
  Iberis gibraltarica L. – accepted – Gibraltar candytuft
  Iberis nudicaulis L. – not accepted
  Iberis sempervirens L. – accepted – evergreen candytuft
  Iberis umbellata L. – accepted – globe candytuft
  Ilex L. – accepted – hollies, holly
  Ilex aquifolium L. – accepted – English holly
  Ilex cassine L. – accepted – dahoon
  Ilex cassine var. cassine L. – not accepted – dahoon
  Illecebrum L. – accepted – coral necklace
  Illecebrum verticillatum L. – accepted – coral necklace
  Illicium L. – accepted – anisetree
  Impatiens L. – accepted – touch-me-not
  Impatiens balsamina L. – accepted – spotted snapweed
  Impatiens noli-tangere L. – accepted – western touch-me-not
  Imperatoria ostruthia L. – not accepted
  Indigofera L. – accepted – indigo
  Indigofera hirsuta L. – accepted – roughhairy indigo
  Indigofera tinctoria L. – accepted – true indigo
  Indigofera trifoliata L. – accepted – threeleaf indigo
  Inula L. – accepted – yellowhead
  Inula britannica L. – accepted – British yellowhead
  Inula brittanica L. – not accepted
  Inula dysenterica L. – not accepted
  Inula helenium L. – accepted – elecampane inula
  Inula mariana L. – not accepted
  Inula salicina L. – accepted – willowleaf yellowhead
  Ipomoea L. – accepted – morningglory, morning-glory
  Ipomoea aegyptia L. – not accepted
  Ipomoea alba L. – accepted – tropical white morningglory, tropical white morning-glory
  Ipomoea bona-nox L. – not accepted
  Ipomoea carolina L. – accepted
  Ipomoea coccinea L. – accepted – Mexican morningglory, red morningglory, starglory, woolly tidestromia, scarlet morningglory, redstar
  Ipomoea hederifolia L. – accepted – scarlet creeper, scarletcreeper
  Ipomoea lacunosa L. – accepted – pitted morningglory, white morningglory, whitestar
  Ipomoea pes-tigridis L. – accepted – morningglory
  Ipomoea quamoclit L. – accepted – cypressvine morningglory, cypressvine
  Ipomoea quinquefolia L. – not accepted
  Ipomoea solanifolia L. – not accepted
  Ipomoea tamnifolia L. – not accepted
  Ipomoea triloba L. – accepted – littlebell, three-lobed morning-glory
  Ipomoea tuberosa L. – not accepted
  Ipomoea violacea L. – accepted – heavenlyblue morning-glory, heavenlyblue morningglory, beach moonflower, ololiuqui, sea moonflower
  Iresine celosia L. – not accepted
  Iresine celosioides L. – not accepted
  Iris L. – accepted – iris
  Iris aphylla L. – accepted – stool iris
  Iris florentina L. – not accepted
  Iris foetidissima L. – accepted – stinking iris
  Iris germanica L. – accepted – orris, German iris
  Iris ochroleuca L. – not accepted
  Iris pseudacorus L. – accepted – yellow flag, paleyellow iris
  Iris pumila L. – accepted – dwarf iris
  Iris sibirica L. – accepted – Siberian iris
  Iris spuria L. – accepted – wild iris, seashore iris
  Iris variegata L. – accepted – Hungarian iris
  Iris verna L. – accepted – dwarf violet iris
  Iris verna var. verna L. – accepted – dwarf violet iris
  Iris versicolor L. – accepted – harlequin blueflag
  Iris versicolor var. versicolor L. – not accepted – harlequin blueflag
  Iris virginica L. – accepted – Virginia iris
  Iris virginica var. virginica L. – not accepted – Virginia iris
  Iris xiphium L. – accepted – Spanish iris
  Isatis L. – accepted – woad
  Isatis tinctoria L. – accepted – dyer's woad
  Ischaemum L. – accepted – murainagrass
  Isnardia palustris L. – not accepted
  Isoetes L. – accepted – isoète, quillwort
  Isoetes lacustris L. – accepted – isoète lacustre, lake quillwort
  Itea L. – accepted – sweetspire
  Itea virginica L. – accepted – Virginia sweetspire
  Iva L. – accepted – marsh elder, iva, marshelder, sumpweed
  Iva annua L. – accepted – annual marsh elder, annual marsh-elder, annual marshelder, seacoast sumpweed
  Iva annua var. annua L. – not accepted – annual marsh-elder, annual marshelder
  Iva frutescens L. – accepted – Jesuit's bark, bigleaf sumpweed
  Iva frutescens ssp. frutescens L. – not accepted – Jesuit's bark
  Ixia L. – accepted – African cornlily
  Ixia maculata L. – accepted – spotted African cornlily
  Ixia polystachya L. – accepted – white-and-yellow-flower cornlily
  Ixia rosea L. – not accepted
  Ixora L. – accepted
  Ixora coccinea L. – accepted – scarlet jungleflame
  Ixora occidentalis L. – not accepted
  Jacquinia L. – accepted
  Jaquinia L. – not accepted – jaguinias
  Jasione L. – accepted
  Jasione montana L. – accepted – sheepbit
  Jasminum L. – accepted – jasmine
  Jasminum grandiflorum L. – accepted
  Jasminum officinale L. – accepted – poet's jasmine
  Jatropha L. – accepted – nettlespurge
  Jatropha curcas L. – accepted – physic nut, Barbados nut
  Jatropha gossypiifolia L. – accepted – bellyache bush
  Jatropha gossypiifolia var. gossypiifolia L. – accepted – bellyache bush
  Jatropha manihot L. – not accepted
  Jatropha multifida L. – accepted – coralbush
  Jatropha urens L. – not accepted
  Juglans L. – accepted – nogal, walnut
  Juglans alba L. – not accepted
  Juglans cinerea L. – accepted – noyer cendré, white walnut, butternut
  Juglans nigra L. – accepted – black walnut, noyer noir
  Juglans regia L. – accepted – English walnut
  Juncus L. – accepted – jonc, rush
  Juncus acutus L. – accepted – spiny rush
  Juncus acutus ssp. acutus L. – accepted
  Juncus articulatus L. – accepted – jointed rush, jointleaf rush
  Juncus biglumis L. – accepted – twoflowered rush
  Juncus bufonius L. – accepted – toad rush
  Juncus bufonius var. bufonius L. – not accepted – toad rush
  Juncus bulbosus L. – accepted – bulbous rush
  Juncus conglomeratus L. – accepted – common rush
  Juncus effusus L. – accepted – lamp rush, common rush
  Juncus effusus ssp. effusus L. – accepted – common rush
  Juncus effusus var. effusus L. – not accepted – common rush
  Juncus filiformis L. – accepted – thread rush
  Juncus inflexus L. – accepted – European meadow rush
  Juncus nodosus L. – accepted – jointed rush, knotted rush
  Juncus nodosus var. nodosus L. – not accepted – knotted rush, jointed rush
  Juncus squarrosus L. – accepted – mosquito rush
  Juncus stygius L. – accepted – moor rush
  Juncus stygius var. stygius L. – accepted
  Juncus trifidus L. – accepted – highland rush
  Juncus trifidus ssp. trifidus L. – not accepted – highland rush
  Juncus triglumis L. – accepted – threehulled rush, three-hulled rush
  Juncus triglumis var. triglumis L. – accepted – three-hulled rush
  Jungermannia L. – accepted
  Jungermannia bicuspidata L. – not accepted
  Jungermannia cilare L. – not accepted
  Jungermannia ciliaris L. – not accepted
  Jungermannia epiphylla L. – not accepted
  Jungermannia furcata L. – not accepted
  Jungermannia julacea L. – not accepted
  Jungermannia lanceolata L. – not accepted
  Jungermannia multifida L. – not accepted
  Jungermannia pinguis L. – not accepted
  Jungermannia reptans L. – not accepted
  Jungermannia trilobata L. – not accepted
  Juniperus L. – accepted – juniper, cedar, cedro, redcedar, sabino
  Juniperus bermudiana L. – accepted – Bermuda cedar
  Juniperus chinensis L. – accepted – Chinese juniper
  Juniperus communis L. – accepted – dwarf juniper, common juniper, genévrier commun
  Juniperus communis var. communis L. – accepted – common juniper
  Juniperus oxycedrus L. – accepted – cade juniper, enebro de bayas rojas, prickly juniper, redberry juniper
  Juniperus phoenicea L. – accepted – Phoenician juniper
  Juniperus sabina L. – accepted – savin
  Juniperus virginiana L. – accepted – eastern red-cedar, genévrier rouge, red cedar juniper, eastern redcedar
  Juniperus virginiana var. virginiana L. – accepted – cèdre rouge, eastern redcedar
  Jussiaea L. – not accepted
  Jussiaea erecta L. – not accepted
  Jussiaea peruviana L. – not accepted
  Jussiaea repens L. – not accepted
  Justicia L. – accepted – water-willow
  Justicia adhatoda L. – accepted – Malabar nut
  Justicia assurgens L. – not accepted
  Justicia betonica L. – accepted – squirrel's tail
  Justicia echioides L. – not accepted
  Justicia gangetica L. – not accepted
  Kaempferia L. – accepted – kaempferia
  Kaempferia galanga L. – accepted – galanga, aromatic ginger
  Kaempferia rotunda L. – accepted – kaempferia, resurrection-lily
  Kaempferia rotundata L. – not accepted
  Kalmia L. – accepted – kalmia, laurel
  Kalmia amgustifolia L. – not accepted
  Kalmia angustifolia L. – accepted – sheep laurel
  Kalmia angustifolia var. angustifolia L. – accepted – sheep laurel
  Kalmia latifolia L. – accepted – mountain laurel
  Kleinhovia L. – accepted
  Kleinhovia hospita L. – accepted – guest tree
  Knautia L. – accepted
  Koenigia L. – accepted
  Koenigia islandica L. – accepted – island purslane
  Krameria L. – accepted – ratany
  Krameria ixine L. – accepted – abrojo colorado
  Kuhnia eupatorioides L. – not accepted
  Lactuca L. – accepted – lettuce
  Lactuca canadensis L. – accepted – Canada lettuce, Florida blue lettuce, wild lettuce
  Lactuca canadensis var. canadensis L. – not accepted – Canada lettuce
  Lactuca indica L. – accepted – Indian lettuce
  Lactuca saligna L. – accepted – willowleaf lettuce, willow-leaf lettuce
  Lactuca sativa L. – accepted – garden lettuce, lettuce
  Lactuca scariola L. – not accepted
  Lactuca serriola L. – accepted – prickly lettuce, China lettuce, wild lettuce
  Lactuca virosa L. – accepted – bitter lettuce
  Lagerstroemia L. – accepted
  Lagerstroemia indica L. – accepted – crapemyrtle
  Lagurus L. – not accepted
  Lagurus L. – accepted – harestail grass
  Lagurus cylindricus L. – not accepted
  Lagurus ovatus L. – accepted – harestail grass
  Lamium L. – accepted – deadnettle
  Lamium album L. – accepted – white deadnettle
  Lamium album var. maculatum L. – not accepted
  Lamium amplexicaule L. – accepted – common henbit, henbit, giraffehead, henbit deadnettle
  Lamium maculatum L. – accepted – spotted henbit
  Lamium purpureum L. – accepted – red deadnettle, purple deadnettle
  Lamium purpureum var. purpureum L. – accepted – purple deadnettle
  Lantana L. – accepted
  Lantana aculeata L. – not accepted
  Lantana camara L. – accepted – largeleaf lantana
  Lantana involucrata L. – accepted – buttonsage
  Lantana involucrata var. involucrata L. – accepted – buttonsage
  Lantana trifolia L. – accepted – threeleaf shrubverbena
  Lapsana L. – accepted – nipplewort
  Lapsana communis L. – accepted – common nipplewort, nipplewort
  Lathyrus L. – accepted – sweet pea, vetchling, peavine, pea
  Lathyrus angulatus L. – accepted – angled pea
  Lathyrus annuus L. – accepted – annual vetchling, cicércula anual
  Lathyrus aphaca L. – accepted – yellow pea
  Lathyrus articulatus L. – not accepted
  Lathyrus cicera L. – accepted – red pea
  Lathyrus clymenum L. – accepted – cicercha purpurina, Spanish vetchling
  Lathyrus hirsutus L. – accepted – Caley pea, Singletary pea
  Lathyrus inconspicuus L. – accepted – inconspicuous pea
  Lathyrus latifolius L. – accepted – perennial pea, everlasting-pea, everlasting peavine, perennial peavine, perennial sweetpea
  Lathyrus nissolia L. – accepted – grass pea
  Lathyrus odoratus L. – accepted – sweetpea
  Lathyrus palustris L. – accepted – marsh pea, marsh vetchling
  Lathyrus pratensis L. – accepted – meadow pea
  Lathyrus sativus L. – accepted – white pea
  Lathyrus sylvestris L. – accepted – flat pea
  Lathyrus tingitanus L. – accepted – Tangier pea
  Lathyrus tuberosus L. – accepted – tuberous sweetpea, earth-nut pea
  Laurus L. – accepted – laurel
  Laurus camphora L. – not accepted
  Laurus cinnamomum L. – not accepted
  Laurus nobilis L. – accepted – sweet bay
  Laurus persea L. – not accepted
  Laurus sassafras L. – not accepted
  Laurus winterana L. – not accepted
  Laurus winteriana L. – not accepted
  Lavandula L. – accepted – lavender
  Lavandula spica L. – not accepted
  Lavandula stoechas L. – accepted – French lavender
  Lavatera L. – accepted – tree mallow, rose mallow
  Lavatera arborea L. – not accepted – tree mallow
  Lavatera cretica L. – not accepted – Cornish mallow
  Lavatera olbia L. – accepted – tree lavatera, tree mallow
  Lavatera thuringiaca L. – accepted – tree lavatera
  Lavatera trimestris L. – accepted – annual mallow
  Lawsonia L. – accepted
  Lawsonia inermis L. – accepted – henna
  Lechea L. – accepted – pinweed
  Lechea major L. – not accepted
  Lechea minor L. – accepted – thymeleaf pinweed, thymeleaved pinweed
  Lecythis ollaria L. – accepted – coco de mono, monkeypod, lecythis
  Ledum L. – not accepted – Labrador tea
  Ledum palustre L. – not accepted – marsh Labrador tea
  Lemna L. – accepted – duckweed
  Lemna gibba L. – accepted – swollen duckweed, inflated duckweed
  Lemna minor L. – accepted – common duckweed, least duckweed, lesser duckweed
  Lemna polyrrhiza L. – not accepted
  Lemna trisulca L. – accepted – star duckweed, ivy-leaf duckweed
  Leontice leontopetaloides L. – not accepted
  Leontodon L. – accepted – hawkbit, leontodon
  Leontodon autumnalis L. – accepted – fall dandelion
  Leontodon autumnalis ssp. autumnalis L. – not accepted – fall dandelion
  Leontodon hastilis L. – not accepted
  Leontodon hispidus L. – accepted – bristly hawkbit, rough hawkbit
  Leontodon hispidus ssp. hispidus L. – not accepted – bristly hawkbit
  Leontodon taraxacum L. – not accepted
  Leonurus L. – accepted – motherwort
  Leonurus cardiaca L. – accepted – motherwort, common motherwort
  Leonurus cardiaca ssp. cardiaca L. – accepted – common motherwort
  Leonurus marrubiastrum L. – not accepted – lion's tail
  Leonurus sibiricus L. – accepted – honeyweed
  Lepidium L. – accepted – pepperweed
  Lepidium bonariense L. – accepted – Argentine pepperweed
  Lepidium chalepensis L. – accepted – lenspod whitetop
  Lepidium didymum L. – accepted – lesser swinecress
  Lepidium draba L. – accepted – whitetop, hoary cress
  Lepidium draba ssp. draba L. – not accepted
  Lepidium graminifolium L. – accepted – grassleaf pepperweed
  Lepidium latifolium L. – accepted – perennial pepperweed, broadleaved peppergrass, tall whitetop, Virginia pepperweed, broadleaf pepperweed, perennial peppercress, peppergrass mustard, broadleaved pepperweed
  Lepidium perfoliatum L. – accepted – clasping pepperwort, claspingleaf pepperweed, clasping pepperweed
  Lepidium ruderale L. – accepted – roadside pepperweed
  Lepidium sativum L. – accepted – garden pepperwort, gardencress pepperweed
  Lepidium virginicum L. – accepted – poorman pepperweed, poorman's pepperwort, peppergrass, poorman's pepper, Virginian peppercress, Virginia pepperweed
  Lepidium virginicum ssp. virginicum L. – accepted – Virginia pepperweed
  Lepidium virginicum var. virginicum L. – not accepted – poorman's-pepperwort, Virginia pepperweed
  Leucojum L. – accepted – snowflake
  Leucojum aestivum L. – accepted – summer snowflake
  Leucojum aestivum ssp. aestivum L. – not accepted – summer snowflake
  Leucojum vernum L. – accepted – spring snowflake
  Ligusticum L. – accepted – privet, licorice-root
  Ligusticum scoticum L. – accepted – Scottish licorice-root
  Ligusticum scoticum ssp. scoticum L. – accepted – Scottish licorice-root
  Ligustrum L. – accepted – privet
  Ligustrum vulgare L. – accepted – wild privet, European privet
  Lilium L. – accepted – lily
  Lilium bulbiferum L. – accepted – orange lily
  Lilium camschatcense L. – not accepted
  Lilium canadense L. – accepted – Canada lily
  Lilium canadense ssp. canadense L. – not accepted – Canada lily
  Lilium candidum L. – accepted – Madonna lily
  Lilium martagon L. – accepted – martagon lily
  Lilium philadelphicum L. – accepted – wood lily
  Lilium philadelphicum var. philadelphicum L. – not accepted – wood lily
  Lilium philadephicum L. – not accepted
  Lilium superbum L. – accepted – turk's-cap lily
  Limodorum tuberosum L. – not accepted
  Limonia L. – accepted
  Limonia acidissima L. – accepted – Indian woodapple
  Limosella L. – accepted – mudwort
  Limosella aquatica L. – accepted – water mudwort, awlleaf mudwort, awl-leaf mudwort, northern mudwort
  Linnaea L. – accepted – twinflower
  Linnaea borealis L. – accepted – American twinflower, northern twinflower, twinflower
  Linnaea borealis ssp. borealis L. – not accepted – American twinflower, twinflower
  Linnaea borealis var. borealis L. – accepted – American twinflower, twinflower
  Linum L. – accepted – flax
  Linum austriacum L. – accepted – Asian flax
  Linum catharticum L. – accepted – fairy flax
  Linum gallicum L. – not accepted
  Linum narbonense L. – accepted – flax
  Linum perenne L. – accepted – blue flax
  Linum trigynum L. – accepted – French flax
  Linum usitatissimum L. – accepted – cultivated flax, common flax
  Linum usitatissimum var. usitatissimum L. – not accepted – cultivated flax
  Linum virginianum L. – accepted – woodland flax
  Linum virginianum var. virginianum L. – not accepted
  Lippia L. – accepted
  Liquidambar L. – accepted – sweetgum
  Liquidambar styraciflua L. – accepted – sweetgum
  Liriodendron L. – accepted – tuliptree
  Liriodendron tulipifera L. – accepted – yellow poplar, tulip poplar, yellow-poplar, tuliptree, bois-jaune, tulip-poplar
  Lithospermum L. – accepted – stoneseed
  Lithospermum arvense L. – not accepted – corn gromwell, puccoon
  Lithospermum officinale L. – accepted – European stoneseed
  Lobelia L. – accepted
  Lobelia assurgens L. – accepted
  Lobelia cardinalis L. – accepted – cardinalflower
  Lobelia cardinalis ssp. cardinalis L. – not accepted – cardinalflower
  Lobelia cardinalis ssp. cardinalis var. cardinalis L. – not accepted – cardinalflower
  Lobelia cliffortiana L. – accepted – cardenala azul
  Lobelia dortmanna L. – accepted – Dortmann's cardinalflower
  Lobelia erinoides L. – not accepted
  Lobelia erinus L. – accepted – edging lobelia
  Lobelia inflata L. – accepted – Indian tobacco, Indian-tobacco
  Lobelia kalmii L. – accepted – brook lobelia, Ontario lobelia
  Lobelia siphilitica L. – accepted – great blue lobelia
  Lobelia siphilitica var. siphilitica L. – accepted – great blue lobelia
  Loeflingia L. – accepted
  Loeselia L. – accepted – false calico
  Lolium L. – accepted – ryegrass
  Lolium perenne L. – accepted – perennial rye grass, perennial ryegrass, Italian ryegrass
  Lolium perenne ssp. perenne L. – not accepted – perennial rye grass, perennial ryegrass
  Lolium perenne var. perenne L. – not accepted
  Lolium temulentum L. – accepted – darnel, poison darnel, Darnel ryegrass
  Lolium temulentum var. temulentum L. – accepted
  Lolium tenue L. – not accepted
  Lonchitis L. – accepted
  Lonchitis hirsuta L. – accepted – tomato fern
  Lonicera L. – accepted – honeysuckle
  Lonicera alba L. – not accepted
  Lonicera alpigena L. – accepted – alpine honeysuckle
  Lonicera caerulea L. – accepted – sweetberry honeysuckle, blue honeysuckle, fly honeysuckle
  Lonicera caprifolium L. – accepted – Italian woodbine
  Lonicera dioica L. – accepted – limber honeysuckle
  Lonicera dioica var. dioica L. – not accepted – limber honeysuckle
  Lonicera periclymenum L. – accepted – European honeysuckle
  Lonicera sempervirens L. – accepted – trumpet honeysuckle
  Lonicera sempervirens var. sempervirens L. – not accepted – trumpet honeysuckle
  Lonicera tatarica L. – accepted – bush honeysuckle, Tatarian honeysuckle
  Lonicera xylosteum L. – accepted – dwarf honeysuckle
  Lotus L. – accepted – trefoil, deervetch
  Lotus angustissimus L. – accepted – slender bird's-foot trefoil
  Lotus arabicus L. – accepted
  Lotus conjugatus L. – accepted
  Lotus corniculatus L. – accepted – bird's-foot trefoil, birdsfoot trefoil, garden bird's-foot-trefoil, garden birdsfoot trefoil, bloomfell, cat's clover, crowtoes, ground honeysuckle, birdfoot deervetch
  Lotus corniculatus var. corniculatus L. – not accepted – bird's-foot trefoil, birdsfoot trefoil
  Lotus corniculatus var. tenuifolius L. – not accepted
  Lotus creticus L. – accepted – Cretan trefoil
  Lotus cytisoides L. – accepted
  Lotus edulis L. – accepted
  Lotus maritimus L. – accepted
  Lotus ornithopodioides L. – accepted
  Lotus peregrinus L. – accepted
  Lotus siliquosus L. – not accepted
  Lotus tetragonolobus L. – accepted – winged pea
  Ludwigia L. – accepted – seedbox, primrose-willow
  Ludwigia alternifolia L. – accepted – bushy seedbox, seedbox
  Lunaria L. – accepted
  Lunaria annua L. – accepted – annual honesty
  Lunaria rediviva L. – accepted – perennial honesty
  Lupinus L. – accepted – lupine, lupins
  Lupinus albus L. – accepted – white lupine
  Lupinus angustifolius L. – accepted – narrowleaf lupine, blue lupine, altramuz azul
  Lupinus luteus L. – accepted – European yellow lupine
  Lupinus perennis L. – accepted – sundial lupine
  Lupinus perennis ssp. perennis L. – accepted – sundial lupine
  Lupinus perennis ssp. perennis var. perennis L. – not accepted – sundial lupine
  Lupinus perennis var. perennis L. – accepted – sundial lupine
  Lupinus pilosus L. – accepted – blue lupine
  Lupinus varius L. – not accepted
  Lychnis L. – not accepted – campion
  Lychnis alpina L. – not accepted – red alpine campion
  Lychnis alpina var. alpina L. – not accepted – red alpine campion
  Lychnis apetala L. – not accepted
  Lychnis chalcedonica L. – not accepted – maltesecross
  Lychnis dioica L. – not accepted
  Lychnis flos-cuculi L. – not accepted – ragged robin
  Lychnis viscaria L. – not accepted – clammy campion
  Lycium L. – accepted – desert-thorn, wolfberry, wolfberry species
  Lycium barbarum L. – accepted – matrimony vine, matrimonyvine, matrimony-vine, common matrimonyvine
  Lycopodium L. – accepted – clubmosses, club moss, clubmoss
  Lycopodium alopecuroides L. – not accepted
  Lycopodium alpinum L. – not accepted – alpine club moss, alpine clubmoss
  Lycopodium annotinum L. – not accepted – clubmoss, stiff club moss, stiff clubmoss
  Lycopodium annotinum var. annotinum L. – not accepted – stiff clubmoss
  Lycopodium carolinianum L. – not accepted
  Lycopodium carolinianum var. carolinianum L. – not accepted
  Lycopodium cernuum L. – not accepted
  Lycopodium clavatum L. – accepted – running clubmoss, common club moss
  Lycopodium clavatum var. clavatum L. – not accepted – running clubmoss
  Lycopodium complanatum L. – not accepted – Christmas green, creeping jenny, groundcedar
  Lycopodium inundatum L. – not accepted
  Lycopodium linifolium L. – not accepted
  Lycopodium obscurum L. – not accepted – ground pine, tree club moss, flat-branched tree-clubmoss
  Lycopodium phlegmaria L. – not accepted
  Lycopodium rupestre L. – not accepted
  Lycopodium selago L. – not accepted
  Lycopsis L. – not accepted
  Lycopsis arvensis L. – not accepted
  Lycopus L. – accepted – water horehound, waterhorehound
  Lycopus europaeus L. – accepted – gypsywort
  Lycopus virginiana L. – not accepted
  Lycopus virginicus L. – accepted – lycope de Virginie, Virginia bugleweed, Virginia water horehound
  Lysimachia L. – accepted – loosestrife, yellow loosestrife
  Lysimachia ciliata L. – accepted – fringed loosestrife, fringed yellow-loosestrife
  Lysimachia monnieri L. – not accepted
  Lysimachia nummularia L. – accepted – moneywort, creeping jenny
  Lysimachia punctata L. – accepted – large yellow loosestrife, spotted loosestrife
  Lysimachia quadrifolia L. – accepted – whorled loosestrife, crosswort, whorled yellow loosestrife
  Lysimachia tenella L. – not accepted
  Lysimachia thyrsiflora L. – accepted – swamp loosestrife, tufted loosestrife, tufted yellow-loosestrife, water loosestrife
  Lysimachia vulgaris L. – accepted – garden yellow loosestrife, garden loosestrife
  Lythrum L. – accepted – loosestrife
  Lythrum hyssopifolia L. – accepted – hyssop loosestrife
  Lythrum hyssopifolium L. – not accepted – hyssop loosestrife
  Lythrum lineare L. – accepted – wand lythrum
  Lythrum salicaria L. – accepted – purple lythrum, rainbow weed, spiked loosestrife, purple loosestrife
  Lythrum thymifolia L. – accepted – thymeleaf loosestrife
  Lythrum virgatum L. – accepted – European wand loosestrife
  Magnolia L. – accepted
  Magnolia grandiflora L. – accepted – laurier tulipier, bull-bay, southern magnolia
  Magnolia virginiana L. – accepted – laurier doux, swamp-bay, sweetbay
  Magnolia virginiana var. tripetala L. – not accepted
  Malachra L. – accepted – leafbract
  Malachra radiata L. – accepted – tropical leafbract
  Malpighia L. – accepted
  Malpighia angustifolia L. – not accepted
  Malpighia coccigera L. – accepted – Singapore holly
  Malpighia crassifolia L. – not accepted
  Malpighia glabra L. – accepted – wild crapemyrtle, Barbados cherry
  Malva L. – accepted – cheeseweed, mallow
  Malva alcea L. – accepted – vervain mallow, hollyhock, mauve alcée
  Malva americana L. – not accepted
  Malva capensis L. – not accepted
  Malva caroliniana L. – not accepted
  Malva coromandeliana L. – not accepted
  Malva mauritiana L. – not accepted
  Malva moschata L. – accepted – musk mallow, mauve musquée
  Malva parviflora L. – accepted – small-whorl mallow, cheeseweed, cheeseweed mallow, small-flowered mallow, mauve parviflore
  Malva rotundifolia L. – not accepted – low mallow
  Malva rotundifolia L. – not accepted
  Malva spicata L. – not accepted
  Malva sylvestris L. – accepted – high mallow, garden mallow
  Malva verticillata L. – accepted – cluster mallow, whorled mallow, clustered mallow, Chinese mallow, curled mallow, mauve verticillée
  Malva verticillata var. crispa L. – not accepted
  Mammea L. – accepted – mamey, mammee
  Mammea americana L. – accepted – mamey, mammee apple
  Mandragora L. – accepted – mandrake
  Mandragora officinarum L. – accepted – mandrake
  Mangifera L. – accepted – mango
  Mangifera indica L. – accepted – mango
  Manisuris L. – accepted
  Manisuris granularis L. – not accepted
  Maranta L. – accepted – maranta
  Maranta arundinaacea L. – not accepted
  Maranta arundinacea L. – accepted – arrowroot
  Marcgravia L. – accepted
  Marchantia L. – accepted
  Marchantia chenopoda L. – accepted
  Marchantia polymorpha L. – accepted
  Marchantia polymorpha ssp. polymorpha L. – accepted
  Marrubium L. – accepted – horehound
  Marrubium candidissimum L. – not accepted
  Marrubium peregrinum L. – accepted – horehound
  Marrubium vulgare L. – accepted – white horehound, horehound
  Marsilea L. – accepted – pepperwort, cloven fern, waterclover
  Marsilea minuta L. – accepted – dwarf waterclover
  Marsilea natans L. – not accepted
  Marsilea quadrifolia L. – accepted – European waterclover
  Martynia L. – accepted
  Martynia annua L. – accepted – una de gato
  Martynia perennis L. – not accepted
  Matricaria L. – accepted – mayweed
  Matricaria chamomilla L. – accepted – German chamomile, crown mayweed
  Matricaria inodora L. – not accepted
  Matricaria maritima L. – not accepted
  Matricaria maritima ssp. maritima L. – not accepted – false mayweed
  Matricaria parthenium L. – not accepted
  Matricaria recutita L. – not accepted – mayweed, German chamomile
  Matricaria suaveolens L. – not accepted
  Matthiola scabra L. – not accepted
  Medeola L. – accepted – Indian cucumber
  Medeola virginiana L. – accepted – Indian cucumber
  Medicago L. – accepted – alfalfa
  Medicago arborea L. – accepted – moon trefoil, tree medic, alfalfa arbórea
  Medicago falcata L. – not accepted
  Medicago lupulina L. – accepted – black medick, black medic clover, black medic, hop clover, hop medic, nonesuch, yellow trefoil
  Medicago marina L. – accepted
  Medicago polymorpha L. – accepted – burclover, bur medick, toothed medick, California burclover, bur clover
  Medicago sativa L. – accepted – alfalfa
  Medicago sativa ssp. sativa L. – accepted – alfalfa
  Melaleuca L. – accepted
  Melampodium L. – accepted – blackfoot, melampodium
  Melampyrum L. – accepted – cowwheat
  Melanthium L. – accepted – bunchflower
  Melanthium virginicum L. – not accepted – Virginia bunchflower
  Melastoma L. – accepted
  Melastoma hirtum L. – not accepted
  Melastoma laevigatum L. – not accepted
  Melastoma malabathricum L. – accepted – Malabar melastome
  Melastoma scabrosum L. – not accepted
  Melia L. – accepted
  Melia azadirachta L. – not accepted
  Melia azedarach L. – accepted – Chinaberry tree, chinaberry, Indian lilac, lelah, paraiso, pride of India, white cedar
  Melianthus L. – accepted
  Melianthus major L. – accepted – honey-flower
  Melica L. – accepted – melic, melicgrass, oniongrass
  Melica altissima L. – accepted – Siberian melicgrass
  Melica ciliata L. – accepted
  Melica papilionacea L. – not accepted
  Melicoccus bijuga L. – not accepted
  Melissa L. – accepted – balm
  Melissa officinalis L. – accepted – common balm
  Melochia L. – accepted – broom-wood
  Melochia corchorifolia L. – accepted – chocolateweed, chocolate weed, hirsute melochia, redweed
  Melochia depressa L. – not accepted
  Melochia pyramidata L. – accepted – pyramidflower, pyramid bush
  Melochia pyramidata var. pyramidata L. – accepted
  Melochia tomentosa L. – accepted – teabush, woolly pyramid bush
  Melochia tomentosa var. tomentosa L. – accepted
  Melochia tormentosa L. – not accepted
  Melothria L. – accepted – melonette
  Melothria pendula L. – accepted – drooping melonette, Guadeloupe cucumber, creeping cucumber, meloncito, meloncito
  Melothria pendula var. pendula L. – not accepted – Guadeloupe cucumber
  Menispermum L. – accepted – moonseed
  Menispermum canadense L. – accepted – Canadian moonseed, common moonseed
  Mentha L. – accepted – mint
  Mentha aquatica L. – accepted – water mint
  Mentha arvensis L. – accepted – field mint, wild mint
  Mentha canadensis L. – not accepted – Canadian mint
  Mentha crispa L. – not accepted
  Mentha gentilis L. – not accepted
  Mentha pulegium L. – accepted – peppermint, pennyroyal
  Mentha sativa L. – not accepted
  Mentha spicata L. – accepted – bush mint, spearmint
  Mentha spicata var. longifolia L. – not accepted
  Mentha spicata var. spicata L. – not accepted – spearmint
  Mentha sylvestris L. – not accepted
  Mentha viridis L. – not accepted
  Mentha X gentilis L. – not accepted – red mint
  Mentha X piperita var. piperita L. – not accepted – peppermint
  Mentha X verticillata L. – accepted – mint
  Mentzelia L. – accepted – stickleaf, blazingstar
  Mentzelia aspera L. – accepted – tropical stickleaf, tropical blazingstar
  Menyanthes L. – accepted – bogbean, buckbean
  Menyanthes trifoliata L. – accepted – buck-bean, common bogbean, bog-bean, buckbean
  Mercurialis L. – accepted
  Mercurialis annua L. – accepted – annual mercury
  Mesembryanthemum L. – accepted – iceplant
  Mesembryanthemum acinaciforme L. – not accepted
  Mesembryanthemum crassifolium L. – not accepted
  Mesembryanthemum crystallinum L. – accepted – ice plant, common iceplant, crystalline iceplant
  Mesembryanthemum edule L. – not accepted
  Mesembryanthemum nodiflorum L. – accepted – slender-leaf iceplant, slenderleaf iceplant
  Mespilus L. – not accepted
  Mespilus arbutifolia L. – not accepted
  Mespilus canadensis L. – not accepted
  Mespilus germanica L. – not accepted – medlar, common medlar
  Mespilus pyracantha L. – not accepted
  Michelia L. – not accepted
  Michelia champaca L. – not accepted
  Michelia champaea L. – not accepted
  Micropus L. – not accepted
  Micropus L. – accepted – cottonseed
  Milium L. – accepted – milletgrass
  Milium capense L. – not accepted
  Milium cimicinum L. – not accepted
  Milium confertum L. – not accepted
  Milium effusum L. – accepted – American milletgrass
  Milium effusum var. effusum L. – accepted
  Milium lendigerum L. – not accepted
  Milium punctatum L. – not accepted
  Mimosa L. – accepted – sensitive plant, mimosa
  Mimosa asperata L. – accepted – Puerto Rico sensitive-briar, black mimosa
  Mimosa casta L. – accepted – graceful mimosa
  Mimosa ceratonia L. – accepted – black ambret
  Mimosa farnesiana L. – not accepted
  Mimosa lebbeck L. – not accepted
  Mimosa muricata L. – not accepted
  Mimosa nilotica L. – not accepted
  Mimosa pigra L. – accepted – black mimosa, amourette, bashful plant, catclaw mimosa, dormilona, giant mimosa, thorny sensitive plant
  Mimosa pigra var. pigra L. – not accepted – black mimosa
  Mimosa plena L. – not accepted
  Mimosa pudica L. – accepted – shameplant
  Mimosa pudica var. pudica L. – accepted – shameplant
  Mimosa quadrivalvis L. – accepted – fourvalve mimosa, mimosa
  Mimosa quadrivalvis var. quadrivalvis L. – accepted – fourvalve mimosa
  Mimosa tortuosa L. – not accepted
  Mimulus L. – not accepted
  Mimulus L. – accepted – monkey-flower, monkeyflower
  Mimulus luteus L. – accepted – blood-drop emlets, yellow monkey-flower, monkey musk
  Mimulus ringens L. – accepted – Allegheny monkey-flower, Allegheny monkeyflower
  Mimulus ringens var. ringens L. – accepted – Allegheny monkeyflower, Allegheny monkey-flower
  Mimusops L. – accepted
  Mimusops elengi L. – accepted – Spanish cherry
  Minuartia L. – accepted – sandwort, stitchwort
  Mirabilis L. – accepted – four-o'clock, four o'clock
  Mirabilis jalapa L. – accepted – common four o'clock, marvel-of-Peru, common four-o'clock, marvel of Peru
  Mirabilis jalapa var. jalapa L. – accepted – marvel of Peru
  Mirabilis longiflora L. – accepted – longtube four o'clock, sweet four o'clock
  Mirabilis longiflora var. longiflora L. – not accepted – sweet four o'clock
  Mitchella L. – accepted
  Mitchella repens L. – accepted – partridgeberry
  Mitella L. – accepted – bishop's-cap, miterwort
  Mitella diphylla L. – accepted – twoleaf miterwort
  Mitella nuda L. – accepted – bare-stem bishop's-cap, naked miterwort
  Mitreola L. – accepted – hornpod
  Mnium fissum L. – not accepted
  Moehringia L. – accepted – sandwort
  Mollugo L. – accepted – carpet-weed, carpetweed
  Mollugo pentaphylla L. – accepted – carpetweed, carpet-weed
  Mollugo tetraphylla L. – not accepted
  Mollugo verticillata L. – accepted – carpetweed, green carpetweed, alfombra, mollugine, Indian chickweed, green carpet-weed, carpet-weed
  Moluccella L. – accepted
  Moluccella laevis L. – accepted – shellflower
  Momordica L. – accepted – balsam-apple, bitter melon, cundeamor
  Momordica balsamina L. – accepted – southern balsampear
  Momordica charantia L. – accepted – balsampear, balsam pear
  Momordica charantia ssp. charantia L. – accepted
  Momordica elaterium L. – not accepted
  Momordica luffa L. – not accepted
  Monarda L. – accepted – beebalm
  Monarda clinopodia L. – accepted – white bergamot
  Monarda didyma L. – accepted – Oswego tea, monarde écarlate, scarlet beebalm
  Monarda fistulosa L. – accepted – wildbergamot horsemint, Oswego-tea, mintleaf beebalm, wildbergamot beebalm, wild bergamot
  Monarda fistulosa ssp. fistulosa L. – not accepted – Oswego-tea, wild bergamot beebalm, wild bergamot
  Monarda fistulosa ssp. fistulosa var. fistulosa L. – not accepted – wild bergamot, Oswego-tea, wildbergamot beebalm
  Monarda fistulosa var. fistulosa L. – accepted – wild bergamot
  Monarda mollis L. – not accepted
  Monarda punctata L. – accepted – spotted beebalm
  Monarda punctata ssp. punctata L. – not accepted – spotted beebalm
  Monarda punctata ssp. punctata var. punctata L. – not accepted – spotted beebalm
  Monarda punctata var. punctata L. – accepted – spotted beebalm
  Monotropa L. – accepted – Indian pipe
  Monotropa hypopithys L. – not accepted – pinesap
  Monotropa hypopitys L. – not accepted
  Monotropa uniflora L. – accepted – Indianpipe, ghost plant, Indian pipe
  Montia L. – accepted – miner's lettuce, water chickweed, minerslettuce
  Montia fontana L. – accepted – Fountain miner's lettuce, annual water minerslettuce
  Montia fontana ssp. fontana L. – not accepted – annual water minerslettuce
  Morinda L. – accepted
  Morinda citrifolia L. – accepted – Indian mulberry
  Morinda royoc L. – accepted – redgal
  Morinda umbellata L. – accepted – redgal
  Morisonia L. – accepted
  Morisonia americana L. – accepted – ratapple
  Morisonia flexuosa L. – not accepted
  Morus L. – accepted – mulberry
  Morus L. – not accepted
  Morus alba L. – accepted – mulberry, white mulberry
  Morus nigra L. – accepted – black mulberry
  Morus papyrifera L. – not accepted
  Morus rubra L. – accepted – red mulberry
  Morus rubra var. rubra L. – not accepted – red mulberry
  Morus tatarica L. – not accepted
  Morus tictoria L. – not accepted
  Morus tinctoria L. – not accepted
  Muntingia L. – accepted
  Muntingia calabura L. – accepted – strawberrytree, calabura, Jamaica cherry
  Murraya exotica L. – not accepted – Chinese box
  Musa L. – accepted – banana
  Musa sapientum L. – not accepted
  Musa troglodytarum L. – accepted – fe'i banana
  Musa X paradisiaca var. paradisiaca L. – not accepted – banana
  Musa X sapientum L. – not accepted
  Mussaenda L. – accepted
  Myagrum L. – accepted
  Myagrum paniculatum L. – not accepted
  Myagrum perfoliatum L. – accepted – bird's-eye cress, birdseye cress
  Myagrum rugosum L. – not accepted
  Myagrum sativum L. – not accepted
  Myosotis L. – accepted – forget-me-not
  Myosotis scorpioides L. – accepted – forget-me-not, yelloweye forget-me-not, true forget-me-not
  Myosotis scorpioides var. arvensis L. – not accepted
  Myosotis virginiana L. – not accepted
  Myosurus L. – accepted – mousetail
  Myosurus minimus L. – not accepted
  Myosurus minimus L. – accepted – tiny mousetail
  Myosurus minimus ssp. minimus L. – not accepted – tiny mousetail
  Myrica L. – accepted – sweetgale
  Myrica aspleniifolia L. – not accepted
  Myrica cerifera L. – not accepted – southern bayberry, wax myrtle
  Myrica cordifolia L. – not accepted – waxberry
  Myrica gale L. – accepted – sweetgale
  Myrica gale var. gale L. – not accepted – sweetgale
  Myriophyllum L. – accepted – water milfoil, watermilfoil
  Myriophyllum spicatum L. – accepted – Eurasian water-milfoil, myriophylle en epi, spiked water milfoil, Eurasian watermilfoil, spike watermilfoil
  Myriophyllum verticillatum L. – accepted – whorled water-milfoil, whorlleaf watermilfoil, whorl-leaf watermilfoil
  Myrsine L. – accepted – colicwood
  Myrtus L. – accepted
  Myrtus communis L. – accepted – myrtle
  Myrtus zuzygium L. – not accepted
  Najas L. – accepted – water nymph, waternymph
  Najas marina L. – accepted – holly-leaf waternymph, holly-leaved waternymph, spiny waternymph, spiny naiad
  Nama L. – accepted – fiddleleaf
  Nama jamaicense L. – not accepted – Jamaicanweed
  Nama jamaicensis L. – accepted – Jamaicanweed
  Napaea L. – accepted
  Napaea dioica L. – accepted – glademallow, glade mallow
  Napaea hermaphrodita L. – not accepted
  Narcissus L. – accepted – daffodil, narcissus
  Narcissus bulbocodium L. – accepted – petticoat daffodil
  Narcissus jonquilla L. – accepted – jonquil
  Narcissus poeticus L. – accepted – poet's narcissus
  Narcissus pseudonarcissus L. – accepted – daffodil, common daffodil
  Narcissus tazetta L. – accepted – cream narcissus
  Nardus L. – accepted – matgrass
  Nardus ciliaris L. – not accepted
  Nardus gangitis L. – not accepted
  Nardus stricta L. – accepted – matgrass
  Narenga porphyrocoma L. – not accepted
  Nepenthes L. – accepted – pitcher plants, pitcherplants
  Nepenthes distillatoria L. – accepted
  Nepeta L. – accepted – catnip
  Nepeta cataria L. – accepted – catmint, catwort, field balm, catnip
  Nephelium L. – accepted
  Nephelium lappaceum L. – accepted – pulasan, rambutan
  Nerium L. – accepted – oleander
  Nerium oleander L. – accepted – oleander
  Nicotiana L. – accepted – tobacco, tobacco
  Nicotiana glutinosa L. – accepted – tobacco
  Nicotiana paniculata L. – accepted – tobacco
  Nicotiana rustica L. – accepted – Aztec tobacco
  Nicotiana tabacum L. – accepted – cultivated tobacco
  Nigella L. – accepted
  Nigella damascena L. – accepted – devil in the bush, love in a mist
  Nigella hispanica L. – accepted – Spanish fennel
  Nigella sativa L. – accepted – black cumin
  Nymphaea L. – accepted – waterlily, water lily
  Nymphaea alba L. – accepted – European white waterlily
  Nymphaea lotus L. – accepted – white Egyptian lotus
  Nyssa L. – accepted – tupelo
  Nyssa aquatica L. – accepted – water tupelo
  Obolaria L. – accepted
  Obolaria virginica L. – accepted – Virginia pennywort
  Ochna L. – accepted
  Ochna jabotapita L. – accepted – bird's-eye bush
  Ocimum L. – accepted – basil
  Ocimum americanum L. – accepted – American basil, hoary basil
  Ocimum basilicum L. – accepted – sweet basil
  Ocimum gratissimum L. – accepted – African basil
  Ocimum sanctum L. – not accepted
  Ocimum tenuiflorum L. – accepted – holy basil
  Oenanthe L. – accepted – waterdropwort
  Oenanthe L. – not accepted
  Oenanthe fistulosa L. – accepted
  Oenanthe pimpenelloides L. – not accepted
  Oenanthe pimpinelloides L. – accepted – corkyfruit waterdropwort
  Oenothera L. – accepted – evening-primrose, eveningprimrose, evening primrose
  Oenothera biennis L. – accepted – hoary eveningprimrose, king's-cureall, common evening-primrose, common evening primrose
  Oenothera fruticosa L. – accepted – narrowleaf evening-primrose, narrowleaf evening primrose
  Oenothera fruticosa ssp. fruticosa L. – accepted – narrowleaf evening primrose, narrowleaf evening-primrose
  Oenothera mollissima L. – accepted – Argentine evening-primrose, Argentine evening primrose
  Oenothera muricata L. – not accepted
  Oenothera pariflora L. – not accepted
  Oenothera parviflora L. – accepted – northern evening-primrose, northern evening primrose
  Oenothera perennis L. – accepted – little evening-primrose, little evening primrose
  Oldenlandia L. – accepted
  Oldenlandia biflora L. – accepted – twoflower mille graines
  Oldenlandia corymbosa L. – accepted – flat-top mille graines, flattop mille graines
  Oldenlandia uniflora L. – accepted – clustered mille graines, oneflower oldenlandia
  Olea L. – not accepted
  Olea L. – accepted – olive
  Olea europaea L. – accepted – olive
  Olea europaea ssp. europaea L. – accepted – European olive
  Olyra L. – not accepted
  Olyra L. – accepted – carrycillo
  Olyra lartifolia L. – not accepted
  Olyra latifolia L. – accepted – carrycillo
  Olyra latifolia var. latifolia L. – not accepted
  Onoclea L. – accepted – sensitive fern
  Onoclea polypodioides L. – not accepted
  Onoclea sensibilis L. – accepted – sensitive fern
  Ononis L. – accepted – restharrow
  Ononis alopecuroides L. – accepted – foxtail restharrow
  Ononis arvensis L. – accepted – field restharrow
  Ononis fruticosa L. – accepted – shrubby restharrow
  Ononis mitissima L. – accepted
  Ononis natrix L. – accepted
  Ononis ornithopodioides L. – accepted
  Ononis pubescens L. – accepted
  Ononis pusilla L. – accepted
  Ononis reclinata L. – accepted
  Ononis repens L. – accepted – common restharrow
  Ononis rotundifolia L. – accepted
  Ononis spinosa L. – accepted – spiny restharrow
  Ononis viscosa L. – accepted
  Onopordum L. – accepted – cottonthistle, cotton thistle
  Onopordum acanthium L. – accepted – Scotch cottonthistle, cotton thistle, heraldic thistle, Scotch cotton thistle, Scotch thistle
  Onopordum acanthium ssp. acanthium L. – accepted – Scotch thistle
  Onopordum illyricum L. – accepted – Illyrian cottonthistle
  Onosma L. – accepted
  Onosma echioides L. – accepted
  Ophioglossum L. – accepted – adder's-tongue, adderstongue
  Ophioglossum lusitanicum L. – accepted – least adder's-tongue
  Ophioglossum lusitanicum var. lusitanicum L. – not accepted
  Ophioglossum palmatum L. – not accepted – hand fern
  Ophioglossum pendulum L. – not accepted – Old World adder's-tongue, Old World adderstongue
  Ophioglossum pendulum ssp. pendulum L. – not accepted – Old World adderstongue
  Ophioglossum reticulatum L. – accepted – netted adder's-tongue, netted adderstongue
  Ophioglossum scandens L. – not accepted
  Ophioglossum vulgatum L. – accepted – herbe sans couture, southern adderstongue, southern adder's-tongue
  Ophrys L. – accepted
  Ophrys cordata L. – not accepted
  Ophrys insectifera L. – accepted – fly orchid
  Orchis L. – accepted
  Orchis maculata L. – not accepted
  Orchis morio L. – accepted – green-winged orchid
  Orchis spectabilis L. – not accepted
  Origanum L. – accepted
  Origanum heracleoticum L. – not accepted
  Origanum majorana L. – accepted – sweet marjoram
  Origanum maru L. – not accepted – Egyptian marjoram
  Origanum onites L. – accepted – pot marjoram
  Origanum syriacum L. – accepted
  Origanum vulgare L. – accepted – oregano
  Ornithogalum L. – accepted – star of Bethlehem
  Ornithogalum bivalve L. – not accepted
  Ornithogalum hirsutum L. – not accepted
  Ornithogalum nutans L. – accepted – drooping star of Bethlehem
  Ornithogalum pyrenaicum L. – accepted – Pyrenees star of Bethlehem
  Ornithogalum umbellatum L. – accepted – Pyrenees Star of Bethlehem, Star-of-Bethlehem, sleepydick
  Ornithopus L. – accepted – bird's-foot
  Ornithopus compressus L. – accepted – yellow bird's-foot, yellow serradella, cornicabra, pie de pájaro
  Ornithopus perpusillus L. – accepted – little white bird's-foot
  Orobanche L. – accepted – broomrape
  Orobanche americana L. – not accepted
  Orobanche ramosa L. – accepted – branched broomrape, hemp broomrape
  Orobanche uniflora L. – accepted – naked broom-rape, naked broomrape, oneflowered broomrape
  Orobanche uniflora var. uniflora L. – not accepted
  Orontium L. – accepted – goldenclub
  Orontium aquaticum L. – accepted – goldenclub
  Oryza L. – accepted – rice
  Oryza sativa L. – accepted – rice
  Osmunda L. – accepted
  Osmunda adiantifolia L. – not accepted
  Osmunda cinnamomea L. – not accepted – cinnamon fern
  Osmunda cinnamomea var. cinnamomea L. – not accepted – cinnamon fern
  Osmunda claytoniana L. – not accepted – interrupted fern
  Osmunda hirsuta L. – not accepted
  Osmunda regalis L. – accepted – royal fern
  Osmunda spicant L. – not accepted
  Osmunda virginiana L. – not accepted
  Osmundum phyllitidis L. – not accepted
  Osteospermum L. – accepted – daisybush
  Osteospermum uvedalia L. – not accepted
  Oxalis L. – accepted – wood sorrel, woodsorrel
  Oxalis barrelieri L. – accepted – Barrelier's woodsorrel
  Oxalis corniculata L. – accepted – yellow oxalis, yellow wood sorrel, 'ihi, creeping oxalis, creeping woodsorrel
  Oxalis corniculata var. corniculata L. – not accepted
  Oxalis frutescens L. – accepted – shrubby oxalis, shrubby woodsorrel
  Oxalis frutescens ssp. frutescens L. – accepted
  Oxalis frutescens var. frutescens L. – not accepted
  Oxalis hirta L. – accepted – tropical woodsorrel
  Oxalis incarnata L. – accepted – crimson woodsorrel
  Oxalis pes-caprae L. – accepted – African woodsorrel, Bermuda buttercup
  Oxalis purpurea L. – accepted – purple woodsorrel
  Oxalis stricta L. – accepted – common yellow oxalis, sheep sorrel, sourgrass, toad sorrel, yellow woodsorrel, erect woodsorrel, upright yellow wood-sorrel, upright yellow woodsorrel
  Oxalis violacea L. – accepted – violet woodsorrel, violet wood-sorrel, purple woodsorrel
  Paederia L. – accepted – sewer vine
  Paederia foetida L. – accepted – skunk vine, stinkvine
  Paeonia L. – accepted – peony
  Paeonia officinalis L. – accepted – common peony
  Panax L. – accepted – ginseng
  Panax quinquefolius L. – accepted – ginseng à cinq folioles, American ginseng
  Panax trifolius L. – accepted – dwarf ginseng
  Pancratium L. – accepted – pancratium
  Pancratium caribaeum L. – not accepted
  Pancratium carolinianum L. – not accepted
  Pancratium maritimum L. – accepted – sea-daffodil
  Panicum L. – accepted – panicum, panicgrass
  Panicum alopecuroides L. – not accepted
  Panicum alopecuroideum L. – not accepted
  Panicum americanum L. – not accepted
  Panicum brevifolium L. – accepted
  Panicum capillare L. – accepted – panicgrass, ticklegrass, tumble panic, tumbleweed grass, witches hair, witchgrass, annual witchgrass, common panic grass, common witchgrass
  Panicum capillare ssp. capillare L. – not accepted
  Panicum capillare var. capillare L. – not accepted
  Panicum clandestinum L. – not accepted – deer-tongue witchgrass
  Panicum colonum L. – not accepted
  Panicum coloratum L. – accepted – klinegrass, kleingrass
  Panicum compositum L. – not accepted
  Panicum crus-galli L. – not accepted
  Panicum crusgalli L. – not accepted
  Panicum dactylon L. – not accepted
  Panicum dichotomum L. – not accepted
  Panicum dichotomum var. dichotomum L. – not accepted
  Panicum dimidiatum L. – not accepted
  Panicum dissectum L. – not accepted
  Panicum distachyon L. – not accepted
  Panicum divaricatum L. – not accepted
  Panicum filiforme L. – not accepted
  Panicum glaucum L. – not accepted
  Panicum grossarium L. – not accepted
  Panicum hirtellum L. – not accepted
  Panicum italicum L. – not accepted
  Panicum italicum var. italicum L. – not accepted
  Panicum latifolium L. – not accepted
  Panicum miliaceum L. – accepted – blackseeded proso millet, panic millet, proso, wild millet, wild proso millet, panicum, broomcorn millet, hog millet, proso millet, broomcorn panic
  Panicum miliaceum ssp. miliaceum L. – accepted – blackseeded proso millet, panic millet, proso, wild millet, wild proso millet, panicum, broomcorn millet, broomcorn panic
  Panicum miliaceum var. miliaceum L. – not accepted
  Panicum polystachion L. – not accepted
  Panicum ramosum L. – not accepted
  Panicum repens L. – accepted – couch panicum, creeping panic, panic rampant, wainaku grass, torpedo grass, torpedograss
  Panicum reptans L. – not accepted
  Panicum sanguinale L. – not accepted
  Panicum sanguinalis L. – not accepted
  Panicum verticillatum L. – not accepted
  Panicum virgatum L. – accepted – old switch panic grass, switchgrass
  Panicum virgatum var. virgatum L. – not accepted – switchgrass
  Panicum viride L. – not accepted
  Papaver L. – accepted – poppy
  Papaver alpinum L. – accepted – alpine poppy, dwarf poppy
  Papaver argemone L. – accepted – long pricklyhead poppy
  Papaver dubium L. – accepted – blindeyes
  Papaver hybridum L. – accepted – round pricklyhead poppy
  Papaver nudicaule L. – accepted – Arctic poppy, Icelandic poppy
  Papaver nudicaule ssp. nudicaule L. – accepted – Icelandic poppy
  Papaver orientale L. – accepted – Oriental poppy
  Papaver rhoeas L. – accepted – corn poppy
  Papaver somniferum L. – accepted – opium poppy
  Parietaria L. – accepted – pellitory
  Parietaria judaica L. – accepted – spreading pellitory
  Parietaria microphylla L. – not accepted
  Parietaria officinalis L. – accepted – upright pellitory
  Parietaria zeylanica L. – not accepted
  Parkinsonia L. – accepted – paloverde
  Parkinsonia aculeata L. – accepted – Jerusalem thorn, Mexican palo verde, Jerusalem-thorn, retama
  Parnassia L. – accepted – grass of Parnassus
  Parnassia palustris L. – accepted – northern grass of Parnassus, marsh grass-of-Parnassus, marsh grass of Parnassus
  Parnassia palustris var. palustris L. – not accepted – Alaska grass of Parnassus
  Parthenium L. – accepted – feverfew
  Parthenium hysterophorus L. – accepted – Santa Maria feverfew, ragweed parthenium, whitetop weed
  Parthenium integrifolium L. – accepted – wild quinine, American feverfew
  Parthenium integrifolium var. integrifolium L. – not accepted – wild quinine
  Paspalum L. – accepted – paspalum, crowngrass
  Paspalum dimidiatum L. – not accepted
  Paspalum distichum L. – accepted – knotgrass, knotroot paspalum
  Paspalum distinctum L. – not accepted
  Paspalum paniculatum L. – accepted – arrocillo
  Paspalum scrobiculatum L. – accepted – ricegrass paspalum, kodomillet, ricegrass, Kodo-millet
  Paspalum virgatum L. – accepted – talquezal
  Passiflora L. – accepted – passionflower
  Passiflora caerulea L. – accepted – blue passionflower, bluecrown passionflower
  Passiflora foetida L. – accepted – stinking passionflower, scarletfruit passionflower, fetid passionflower
  Passiflora foetida var. foetida L. – accepted – fetid passionflower
  Passiflora incarnata L. – accepted – purple passionflower
  Passiflora laurifolia L. – accepted – golden bellapple
  Passiflora lutea L. – accepted – passionflower, yellow passionflower
  Passiflora maliformis L. – accepted – conch apple
  Passiflora multiflora L. – accepted – whiteflower passionflower
  Passiflora murucuja L. – accepted – Virgin Island passionflower
  Passiflora pallida L. – accepted – corkystem passionflower
  Passiflora quadrangularis L. – accepted – giant granadilla
  Passiflora rubra L. – accepted – dutchman's laudanum
  Passiflora serrato-digitata L. – not accepted
  Passiflora serratodigitata L. – accepted – tagua tagua
  Passiflora suberosa L. – accepted – corky passionflower, devil's pumpkin, huehue haole, indigo berry, wild passionfruit, maypop, corkystem passionflower
  Pastinaca L. – accepted – parsnip
  Pastinaca sativa L. – accepted – wild parsnip
  Pastinaca sativa var. sativa L. – not accepted – wild parsnip
  Paullinia L. – accepted – bread and cheese
  Paullinia pinnata L. – accepted – bread and cheese
  Pavonia typhalaea L. – not accepted
  Pectis L. – accepted – chinchweed, fetid marigold, cinchweed, fetidmarigold
  Pectis ciliaris L. – accepted – donkeyweed
  Pectis linifolia L. – accepted – romero macho, narrowleaf lemonweed
  Pedicularis L. – accepted – lousewort
  Pedicularis canadensis L. – accepted – early lousewort, Canadian lousewort
  Pedicularis canadensis ssp. canadensis L. – not accepted – Canadian lousewort
  Pedicularis canadensis ssp. canadensis var. canadensis L. – not accepted – Canadian lousewort
  Pedicularis flammea L. – accepted – redrattle
  Pedicularis hirsuta L. – accepted – hairy lousewort
  Pedicularis lapponica L. – accepted – Lapland lousewort
  Pedicularis palustris L. – accepted – European purple lousewort, swamp-lousewort
  Pedicularis palustris ssp. palustris L. – accepted – European purple lousewort, swamp-lousewort
  Pedicularis sylvatica L. – accepted – small lousewort, lousewort
  Pedicularis verticillata L. – accepted – whorled lousewort
  Peganum L. – accepted
  Peganum harmala L. – accepted – African rue, harmal shrub, isband, ozallaik, steppenraute, Syrian rue, harmel, peganum, harmal peganum
  Pentapetes L. – accepted
  Pentapetes phoenica L. – not accepted
  Pentapetes phoenicea L. – accepted – flor impia
  Penthorum L. – accepted
  Penthorum sedoides L. – accepted – Virginia penthorum, ditch stonecrop
  Peplis portula L. – not accepted
  Pergularia L. – accepted
  Perilla L. – accepted – perilla
  Perilla ocymoides L. – not accepted
  Periploca L. – accepted
  Periploca graeca L. – accepted – Grecian silkvine, silkvine
  Petiveria L. – accepted
  Petiveria alliacea L. – accepted – guinea henweed
  Petrea L. – accepted
  Petrea volubilis L. – accepted – queen's-wreath
  Peucedanum L. – accepted
  Peucedanum officinale L. – accepted – hog's-fennel, sulphurweed
  Phalaris L. – accepted – canarygrass
  Phalaris aquatica L. – accepted – Harding grass, Hardinggrass, bulbous canarygrass
  Phalaris aquatica var. aquatica L. – not accepted
  Phalaris arundinacea L. – accepted – reed canary grass, reed canarygrass
  Phalaris arundinacea f. arundinacea L. – not accepted
  Phalaris arundinacea var. arundinacea L. – accepted
  Phalaris arundinacea var. picta L. – accepted
  Phalaris bulbosa L. – not accepted
  Phalaris canariensis L. – accepted – common canary grass, common canarygrass, annual canarygrass
  Phalaris oryzoides L. – not accepted
  Phalaris paradoxa L. – accepted – hood canarygrass
  Phalaris paradoxa var. paradoxa L. – not accepted
  Phalaris tuberosa L. – not accepted
  Phalaris tuberosa var. tuberosa L. – not accepted
  Phalaris utriculata L. – not accepted
  Phalaris zizanioides L. – not accepted
  Pharus L. – accepted – stalkgrass
  Pharus latifolius L. – accepted – broad stalkgrass
  Pharus latifolius var. latifolius L. – not accepted
  Phaseolus L. – not accepted
  Phaseolus L. – accepted – bean, wild bean
  Phaseolus caracalla L. – not accepted
  Phaseolus coccineus L. – accepted – scarlet runner
  Phaseolus cylindricus L. – not accepted
  Phaseolus inamoenus L. – not accepted
  Phaseolus lathyroides L. – not accepted
  Phaseolus lunatus L. – accepted – sieva bean
  Phaseolus max L. – not accepted
  Phaseolus mungo L. – not accepted
  Phaseolus radiatus L. – not accepted
  Phaseolus semierectus L. – not accepted
  Phaseolus vulgaris L. – accepted – kidney bean
  Phellandrium L. – not accepted
  Philadelphus L. – accepted – mockorange, mock orange
  Philadelphus coronarius L. – accepted – sweet mock orange
  Philadelphus inodorus L. – accepted – scentless mock orange
  Philadelphus inodorus var. inodorus L. – not accepted – scentless mockorange
  Phleum L. – accepted – timothy
  Phleum alpinum L. – accepted – alpine timothy
  Phleum alpinum f. alpinum L. – not accepted
  Phleum alpinum ssp. alpinum L. – accepted
  Phleum arenarium L. – accepted – sand timothy
  Phleum nodosum L. – not accepted
  Phleum pratense L. – accepted – common timothy, timothy
  Phleum pratense ssp. pratense L. – accepted – common timothy
  Phleum schoenoides L. – not accepted
  Phlomis L. – accepted – Jerusalem sage
  Phlomis fruticosa L. – accepted – shrubby Jerusalem sage
  Phlomis tuberosa L. – accepted – tuberous Jerusalem sage
  Phlox L. – accepted – phlox
  Phlox carolina L. – accepted – thickleaf phlox
  Phlox carolina ssp. carolina L. – accepted – thickleaf phlox
  Phlox divaricata L. – accepted – wild blue phlox
  Phlox divaricata ssp. divaricata L. – accepted – wild blue phlox
  Phlox glaberrima L. – accepted – smooth phlox
  Phlox glaberrima ssp. glaberrima L. – accepted – smooth phlox
  Phlox maculata L. – accepted – wild sweetwilliam
  Phlox maculata ssp. maculata L. – accepted – wild sweetwilliam
  Phlox paniculata L. – accepted – fall phlox
  Phlox pilosa L. – accepted – downy phlox
  Phlox pilosa ssp. pilosa L. – accepted – downy phlox
  Phlox sibirica L. – accepted – Siberian phlox
  Phlox sibirica ssp. sibirica L. – accepted
  Phlox sibirica var. sibirica L. – not accepted
  Phlox subulata L. – accepted – moss phlox
  Phlox subulata ssp. subulata L. – accepted – moss phlox
  Phoenix L. – accepted – date palm
  Phoenix dactylifera L. – accepted – date palm
  Phryma L. – accepted
  Phryma leptostachya L. – accepted – lopseed, American lopseed
  Phryma leptostachya var. leptostachya L. – accepted – American lopseed
  Phryma leptostachys L. – not accepted
  Phyllanthus L. – accepted – leaf flower, leafflower
  Phyllanthus emblica L. – accepted – emblic
  Phyllanthus epiphyllanthus L. – accepted – swordbush
  Phyllanthus niruri L. – accepted – gale of the wind
  Phyllanthus niruri ssp. niruri L. – not accepted – gale of the wind
  Phyllanthus nirurui L. – not accepted
  Phyllanthus urinaria L. – accepted – chamber bitter
  Physalis L. – accepted – groundcherry, ground cherry
  Physalis alkekengi L. – accepted – strawberry groundcherry
  Physalis angulata L. – accepted – cutleaf groundcherry, cut-leaf ground-cherry, lanceleaf groundcherry
  Physalis minima L. – accepted – pygmy groundcherry
  Physalis peruviana L. – accepted – Peruvian groundcherry
  Physalis pubescens L. – accepted – husk tomato, groundcherry, husk-tomato
  Physalis pubescens var. pubescens L. – accepted – husk tomato
  Physalis viscosa L. – accepted – starhair groundcherry, grape groundcherry, groundcherry
  Physalis viscosa var. viscosa L. – not accepted
  Phytolacca L. – accepted – pokeweed
  Phytolacca americana L. – accepted – pokeweed, inkberry, pigeonberry, pokeberry, common pokeweed, phytolaque d'Amérique, poke, American pokeweed
  Phytolacca americana var. americana L. – accepted – American pokeweed
  Phytolacca decandra L. – not accepted
  Phytolacca icosandra L. – accepted – tropical pokeweed
  Phytolacca octandra L. – accepted – red inkplant
  Picris L. – accepted – oxtongue
  Picris echioides L. – not accepted – bristly oxtongue
  Picris hieracioides L. – accepted – hawkweed oxtongue
  Picris hieracioides ssp. hieracioides L. – not accepted – hawkweed oxtongue
  Picris hieracioides ssp. hieracioides var. hieracioides L. – not accepted – hawkweed oxtongue
  Pilularia L. – accepted – pillwort
  Pilularia globulifera L. – accepted
  Pimpinella L. – accepted – burnet saxifrage
  Pimpinella anisum L. – accepted – anise burnet saxifrage
  Pimpinella magna L. – not accepted
  Pimpinella saxifraga L. – accepted – solidstem burnet saxifrage
  Pimpinella saxifraga ssp. saxifraga L. – accepted – solidstem burnet saxifrage
  Pimpinella saxifraga var. major L. – not accepted
  Pinguicula L. – accepted – butterwort
  Pinguicula villosa L. – accepted – hairy butterwort
  Pinguicula vulgaris L. – accepted – common butterwort
  Pinguicula vulgaris ssp. vulgaris L. – accepted – common butterwort
  Pinus L. – accepted – pine
  Pinus balsamea L. – not accepted
  Pinus canadensis L. – not accepted
  Pinus cedrus L. – not accepted
  Pinus cembra L. – accepted – Swiss stone pine
  Pinus larix L. – not accepted
  Pinus pinea L. – accepted – Italian stone pine
  Pinus strobus L. – accepted – eastern white pine, white pine, northern white pine, soft pine, Weymouth pine
  Pinus sylvestris L. – accepted – Scots pine
  Pinus taeda L. – accepted – loblolly pine
  Piper L. – accepted – pepper
  Piper aducum L. – not accepted
  Piper aduncum L. – accepted – spiked pepper, higuillo de hoja menuda
  Piper amalago L. – accepted – higuillo de limon
  Piper betel L. – not accepted
  Piper betle L. – accepted – betel pepper
  Piper longum L. – accepted – Indian long pepper
  Piper maculosum L. – not accepted
  Piper nigrum L. – accepted – black pepper
  Piper obtusifolium L. – not accepted
  Piper pellucidum L. – not accepted
  Piper peltatum L. – accepted
  Piper quadrifolium L. – not accepted
  Piper reticulatum L. – accepted
  Piper rotundifolium L. – not accepted
  Piper umbellatum L. – accepted
  Piriqueta ulmifolia L. – not accepted
  Piscidia L. – accepted
  Piscidia erythrina L. – not accepted
  Pisonia L. – accepted – catchbirdtree
  Pisonia aculeata L. – accepted – pullback
  Pistacia L. – accepted – pistache
  Pistacia lentiscus L. – accepted – mastic tree
  Pistacia simaruba L. – not accepted
  Pistacia terebinthus L. – accepted – Cyprus turpentine
  Pistacia vera L. – accepted – pistachio nut
  Pistia L. – accepted
  Pistia stratiotes L. – accepted – water lettuce, water-lettuce, apon-apon, laitue d'eau, lechuguita de agua, pistie, tropical duckweed
  Pisum L. – accepted – pea
  Pisum arvense L. – not accepted
  Pisum maritimum L. – not accepted
  Pisum sativum L. – accepted – garden pea
  Pisum sativum ssp. sativum L. – not accepted – garden pea
  Pisum sativum var. sativum L. – accepted – garden pea
  Plantago L. – accepted – Indianwheat, plantain
  Plantago coronopus L. – accepted – buckhorn plantain
  Plantago indica L. – not accepted
  Plantago lanceolata L. – accepted – buckhorn plantain, English plantain, lanceleaf Indianwheat, lanceleaf plantain, ribgrass, ribwort, narrowleaf plantain
  Plantago major L. – accepted – broadleaf plantain, great plantain, buckhorn plantain, rippleseed plantain, common plantain
  Plantago major var. major L. – not accepted – common plantain
  Plantago maritima L. – accepted – goose tongue
  Plantago maritima var. maritima L. – accepted
  Plantago media L. – accepted – lanceleaf plantain, hoary plantain
  Plantago psyllium L. – accepted – sand plantain
  Plantago virginica L. – accepted – paleseed Indianwheat, Virginia plantain
  Platanus L. – accepted – sycamore
  Platanus occidentalis L. – accepted – sycamore, American sycamore
  Platanus orientalis L. – accepted – Oriental planetree
  Plinia L. – accepted
  Plukenetia L. – accepted
  Plumbago L. – accepted – leadwort
  Plumbago indica L. – accepted – whorled plantain
  Plumbago rosea L. – not accepted
  Plumbago scandens L. – not accepted – plumbago, doctorbush
  Plumbago zeylanica L. – accepted – wild leadwort
  Plumeria L. – accepted
  Plumeria alba L. – accepted – nosegaytree
  Plumeria obtusa L. – accepted – Singapore graveyard flower
  Plumeria obtusa var. obtusa L. – accepted – Singapore graveyard flower
  Plumeria rubra L. – accepted – frangipani, templetree
  Poa L. – accepted – bluegrass, bluegrass spp.
  Poa alpina L. – accepted – alpine bluegrass
  Poa alpina ssp. alpina L. – accepted – alpine bluegrass
  Poa alpina var. vivipara L. – not accepted
  Poa amabilis L. – not accepted
  Poa angustifolia L. – not accepted
  Poa annua L. – accepted – annual blue grass, walkgrass, annual bluegrass
  Poa annua var. annua L. – not accepted
  Poa aquatica L. – not accepted
  Poa bulbosa L. – accepted – bulbous blue grass, bulbous bluegrass
  Poa bulbosa ssp. bulbosa L. – accepted
  Poa capillaris L. – not accepted
  Poa ciliaris L. – not accepted
  Poa compressa L. – accepted – flat-stem blue grass, Canada bluegrass
  Poa distans L. – not accepted
  Poa eragrostis L. – not accepted
  Poa flava L. – not accepted
  Poa nemoralis L. – accepted – forest blue grass, wood bluegrass
  Poa nemoralis ssp. nemoralis L. – not accepted – wood bluegrass
  Poa nemoralis var. nemoralis L. – accepted
  Poa palustris L. – accepted – fowl blue grass, fowl bluegrass
  Poa pilosa L. – not accepted
  Poa pratensis L. – accepted – Kentucky bluegrass
  Poa pratensis ssp. pratensis L. – accepted – Kentucky bluegrass
  Poa pratensis var. pratensis L. – not accepted
  Poa rigida L. – not accepted
  Poa tenella L. – not accepted
  Poa trivialis L. – accepted – rough bluegrass
  Poa trivialis ssp. trivialis L. – accepted
  Podophyllum L. – accepted – mayapple
  Podophyllum peltatum L. – accepted – May apple, podophylle pelté, mayapple, pomme de mai, wild-mandrake, Indian-apple
  Poinciana pulcherrima L. – not accepted
  Polemonium L. – accepted – Jacob's-ladder
  Polemonium caeruleum L. – accepted – charity
  Polemonium reptans L. – accepted – Greek valerian, creeping polemonium
  Polemonium reptans var. reptans L. – accepted – Greek valerian
  Polianthes L. – accepted – polianthes
  Polianthes tuberosa L. – accepted – tuberose, Nardo común
  Polycarpon L. – accepted – manyseed
  Polycnemum L. – accepted
  Polycnemum arvense L. – accepted – field needleleaf
  Polygala L. – accepted – milkwort
  Polygala cruciata L. – accepted – drumheads
  Polygala cruciata var. cruciata L. – accepted – drumheads
  Polygala incarnata L. – accepted – procession flower
  Polygala lutea L. – accepted – orange milkwort
  Polygala myrtifolia L. – accepted – myrtle-leaf milkwort
  Polygala paniculata L. – accepted – orosne
  Polygala penaea L. – not accepted – crevajosa
  Polygala penaea var. penaea L. – not accepted
  Polygala sanguinea L. – accepted – blood milkwort, purple milkwort
  Polygala senega L. – accepted – Seneca snakeroot
  Polygala senega var. senega L. – not accepted – Seneca snakeroot
  Polygala verticillata L. – accepted – whorled milkwort
  Polygala verticillata var. verticillata L. – accepted – whorled milkwort
  Polygala viridescens L. – not accepted
  Polygala vulgaris L. – accepted – common milkwort
  Polygonum L. – accepted – smartweed species, knotweed
  Polygonum amphibium L. – not accepted – water knotweed, water smartweed
  Polygonum arifolium L. – not accepted – halberdleaf tearthumb
  Polygonum articulatum L. – not accepted
  Polygonum aviculare L. – accepted – prostrate knotweed, yard knotweed
  Polygonum aviculare ssp. aviculare L. – accepted – common knotweed
  Polygonum bistorta L. – not accepted – meadow bistort
  Polygonum bistorta var. bistorta L. – not accepted – meadow bistort
  Polygonum chinense L. – not accepted – Chinese knotweed
  Polygonum convolvulus L. – not accepted – black bindweed, black-bindweed, climbing knotweed, pink smartweed, wild buckwheat, climbing buckwheat, cornbind, dullseed cornbind
  Polygonum convolvulus var. convolvulus L. – not accepted – wild buckwheat, black bindweed
  Polygonum dumetorum L. – not accepted
  Polygonum erectum L. – accepted – erect knotweed, devil's shoestring, wireweed
  Polygonum fagopyrum L. – not accepted
  Polygonum hydropiper L. – not accepted – marshpepper knotweed, mild water-pepper, annual smartweed
  Polygonum lapathifolium L. – not accepted – curlytop knotweed, curltop ladysthumb, dock-leaf smartweed, nodding smartweed, pale smartweed, curlytop smartweed
  Polygonum lapathifolium var. lapathifolium L. – not accepted – curlytop knotweed
  Polygonum maritinum L. – not accepted
  Polygonum orientale L. – not accepted – princesfeather, kiss me over the garden gate
  Polygonum pensylvanicum L. – not accepted – pinkweed, Pennsylvania knotweed, pinweed, Pennsylvania smartweed
  Polygonum perfoliatum L. – not accepted – Asiatic tearthumb, mile-a-minute weed
  Polygonum persicaria L. – not accepted – lady's-thumb, spotted smartweed, ladysthumb, ladysthumb smartweed, spotted knotweed, spotted ladysthumb
  Polygonum sagittatum L. – not accepted – arrowleaf tearthumb, arrow-leaf tearthumb, arrowleaf knotweed, arrowvine
  Polygonum scandens L. – not accepted – climbing false buckwheat, climbing knotweed
  Polygonum scandens var. scandens L. – not accepted – climbing false buckwheat
  Polygonum tataricum L. – not accepted
  Polygonum uvifera L. – not accepted
  Polygonum virginianum L. – not accepted – jumpseed, Virginia smartweed
  Polygonum viviparum L. – not accepted – serpent-grass, viviparous bistort, alpine bistort
  Polymnia L. – accepted – polymnia
  Polymnia canadensis L. – accepted – whiteflower leafcup, rayless leafcup
  Polyonum L. – not accepted
  Polypodium L. – not accepted
  Polypodium L. – accepted – polypody
  Polypodium aspleniifolium L. – not accepted
  Polypodium aureum L. – not accepted
  Polypodium cambricum L. – accepted
  Polypodium crassifolium L. – not accepted
  Polypodium dissimile L. – not accepted – forkvein polypody
  Polypodium heterophyllum L. – not accepted
  Polypodium lanceolatum L. – accepted – lanceleaf polypody
  Polypodium locopodioides L. – not accepted
  Polypodium loriceum L. – not accepted – clambering polypody
  Polypodium lycopodioides L. – not accepted
  Polypodium noveboracense L. – not accepted
  Polypodium pectinatum L. – not accepted
  Polypodium phyllitidis L. – not accepted
  Polypodium phymatodes L. – not accepted
  Polypodium piloselloides L. – not accepted
  Polypodium reticulatum L. – not accepted
  Polypodium squamatum L. – not accepted
  Polypodium taxifolium L. – not accepted
  Polypodium trifurcatum L. – not accepted
  Polypodium villosum L. – not accepted
  Polypodium virginianum L. – accepted – rock polypody
  Polypodium vulgare L. – accepted
  Polypremum L. – accepted
  Polypremum procumbens L. – accepted – juniper-leaf
  Pontederia L. – accepted – pontederia, pickerel-weed, pickerelweed
  Pontederia (Pontederia) L. – accepted
  Pontederia cordata L. – accepted – pickerelweed
  Pontederia cordata var. cordata L. – not accepted – pickerelweed
  Pontederia hastata L. – accepted
  Populus L. – accepted – cottonwood
  Populus alba L. – accepted – white poplar
  Populus balsamifera L. – accepted – balsam poplar
  Populus balsamifera ssp. balsamifera L. – not accepted – balsam poplar
  Populus heterophylla L. – accepted – swamp cottonwood
  Populus nigra L. – accepted – black cottonwood, black poplar, Lombardy's poplar
  Populus tremula L. – accepted – European aspen
  Populus tremula var. tremula L. – not accepted
  Porella L. – accepted
  Porella L. – not accepted
  Porella pinnata L. – accepted
  Portulaca L. – accepted – purslane
  Portulaca halimoides L. – accepted – silkcotton purslane, silk-cotton purslane, sinkerleaf purslane
  Portulaca oleracea L. – accepted – little hogweed, little-hogweed, purslane, common purslane, akulikuli-kula, duckweed, pursley, wild portulaca, garden purslane
  Portulaca oleracea ssp. oleracea L. – not accepted – little hogweed
  Portulaca pilosa L. – accepted – kiss-me-quick, chisme, kiss me quick
  Portulaca portulacastrum L. – not accepted
  Portulaca quadrifida L. – accepted – chickenweed
  Potamogeton L. – accepted – pondweed
  Potamogeton crispus L. – accepted – curly-leaved pondweed, curly pondweed
  Potamogeton gramineus L. – accepted – grassy pondweed, variableleaf pondweed
  Potamogeton natans L. – accepted – floatingleaf pondweed, broadleaf pondweed, floating pondweed
  Potamogeton pectinatus L. – not accepted – sago pondweed
  Potamogeton perfoliatus L. – accepted – claspingleaf pondweed
  Potamogeton perfoliatus var. perfoliatus L. – not accepted
  Potamogeton pusillus L. – accepted – baby pondweed, small pondweed
  Potamogeton pusillus ssp. pusillus L. – accepted – small pondweed
  Potentilla L. – accepted – Potentilles, cinquefoil
  Potentilla alba L. – accepted – white cinquefoil
  Potentilla anserina L. – accepted – silverweed cinquefoil
  Potentilla anserina ssp. anserina L. – accepted – silverweed cinquefoil
  Potentilla anserina var. anserina L. – not accepted
  Potentilla argentea L. – accepted – silver-leaf cinquefoil, silver cinquefoil
  Potentilla argentea var. argentea L. – not accepted – silver-leaf cinquefoil, silver cinquefoil
  Potentilla canadensis L. – accepted – dwarf cinquefoil
  Potentilla canadensis var. canadensis L. – not accepted – dwarf cinquefoil
  Potentilla intermedia L. – accepted – downy cinquefoil
  Potentilla monspeliensis L. – not accepted
  Potentilla nivea L. – accepted – snow cinquefoil, snowy cinquefoil
  Potentilla nivea var. nivea L. – not accepted – snow cinquefoil
  Potentilla norvegica L. – accepted – Norwegian cinquefoil
  Potentilla norvegica ssp. norvegica L. – not accepted – Norwegian cinquefoil
  Potentilla pensylvanica L. – accepted – prairie cinquefoil, Pennsylvania cinquefoil
  Potentilla pensylvanica var. pensylvanica L. – not accepted – Pennsylvania cinquefoil
  Potentilla recta L. – accepted – roughfruit cinquefoil, erect cinquefoil, sulphur cinquefoil
  Potentilla reptans L. – accepted – creeping cinquefoil
  Potentilla rupestris L. – accepted
  Potentilla stipularis L. – accepted – stipulated cinquefoil
  Potentilla supina L. – accepted – spreading cinquefoil, bushy cinquefoil
  Potentilla verna L. – accepted – spring cinquefoil
  Poterium L. – not accepted
  Poterium sanguisorba L. – not accepted – salad burnet, fodder burnet, burnet bloodwort
  Pothos pinnatus L. – not accepted
  Premna L. – accepted
  Premna serratifolia L. – accepted
  Prenanthes L. – accepted – rattlesnakeroot
  Prenanthes alba L. – accepted – white rattlesnakeroot, white rattlesnake-root
  Prenanthes alba var. alba L. – not accepted
  Prenanthes altissima L. – accepted – tall rattlesnakeroot, rattlesnakeroot
  Prenanthes japonica L. – not accepted
  Primula L. – accepted – shootingstar, primrose
  Primula veris L. – accepted – cowslip primrose
  Proserpinaca L. – accepted – mermaidweed
  Proserpinaca palustris L. – accepted – marsh mermaid-weed, proserpinie des marais, marsh mermaidweed
  Proserpinaca palustris var. palustris L. – accepted – marsh mermaidweed
  Prosopis L. – accepted – mesquite
  Protea L. – accepted
  Prunella L. – not accepted
  Prunella L. – accepted – selfheal
  Prunella vulgaris L. – accepted – heal all, healall, selfheal, common selfheal
  Prunella vulgaris ssp. vulgaris L. – accepted – common selfheal
  Prunella vulgaris var. vulgaris L. – not accepted – self-heal
  Prunus L. – accepted – chokecherry, plum
  Prunus armeniaca L. – accepted – Siberian apricot, albaricoque, damasco, apricot
  Prunus cerasus L. – accepted – sour cherry
  Prunus cerasus var. avium L. – not accepted
  Prunus domestica L. – accepted – European plum
  Prunus domestica ssp. domestica L. – not accepted – garden plum
  Prunus domestica var. domestica L. – not accepted – European plum
  Prunus insititia L. – accepted
  Prunus laurocerasus L. – accepted – cherry laurel
  Prunus lusitanica L. – accepted – Portuguese laurel, Portuguese laurel cherry, Portugal laurel
  Prunus mahaleb L. – accepted – perfumed cherry, Mahaleb cherry
  Prunus padus L. – accepted – European bird cherry
  Prunus pumila L. – accepted – sandcherry, sand cherry
  Prunus pumila var. pumila L. – accepted – Great Lakes sandcherry
  Prunus pumula L. – not accepted
  Prunus spinosa L. – accepted – blackthorn
  Prunus virginiana L. – accepted – chokecherry, common chokecherry, Virginia chokecherry
  Prunus virginiana var. virginiana L. – accepted – chokecherry
  Psidium L. – accepted – guavas
  Psidium guajava L. – accepted – guava, abas, goyavier, guabang, kautonga, kuahpa
  Psoralea L. – accepted
  Psoralea americana L. – not accepted
  Psoralea bituminosa L. – not accepted
  Psoralea corylifolia L. – not accepted
  Psoralea glandulosa L. – not accepted
  Psoralea pentaphylla L. – not accepted
  Psychotria L. – accepted – wild coffee
  Ptelea L. – accepted – hoptree
  Ptelea trifoliata L. – accepted – common hoptree, hoptree
  Ptelea trifoliata ssp. trifoliata L. – accepted – common hoptree
  Ptelea trifoliata ssp. trifoliata var. trifoliata L. – not accepted – common hoptree
  Ptelea trifoliata var. trifoliata L. – accepted – common hoptree
  Ptelea viscosa L. – not accepted
  Pteris L. – accepted – brake fern
  Pteris aquilina L. – not accepted
  Pteris arborea L. – accepted – tree brake
  Pteris biaurita L. – accepted – thinleaf brake
  Pteris caudata L. – not accepted
  Pteris cretica L. – accepted – Cretan brake
  Pteris cretica var. cretica L. – accepted – Cretan brake
  Pteris grandifolia L. – accepted – elephantleaf brake
  Pteris heterophylla L. – not accepted
  Pteris longifolia L. – accepted – longleaf brake
  Pteris mutilata L. – accepted – Asian brake
  Pteris vittata L. – accepted – ladder brake, Chinese brake
  Pulmonaria L. – accepted – lungwort
  Pulmonaria officinalis L. – accepted – common lungwort
  Punica L. – accepted – pomegranate
  Punica granatum L. – accepted – pomegranate
  Pyrola L. – accepted – shineleaf, wintergreen
  Pyrola minor L. – accepted – snowline wintergreen, lesser wintergreen
  Pyrola rotundifolia L. – accepted
  Pyrola secunda L. – not accepted
  Pyrola uniflora L. – not accepted
  Pyrus L. – accepted – pear
  Pyrus baccata L. – not accepted
  Pyrus communis L. – accepted – common pear, pear
  Pyrus coronaria L. – not accepted
  Pyrus cydonia L. – not accepted
  Pyrus malus L. – not accepted
  Pyrus malus var. paradisiaca L. – not accepted
  Pyrus malus var. sylvestris L. – not accepted
  Quassia L. – accepted
  Quassia amara L. – accepted – quassia-wood, bitterwood, quassia wood
  Quercus L. – accepted – chêne, oak
  Quercus alba L. – accepted – chêne blanc, white oak
  Quercus cerris L. – accepted – European turkey oak
  Quercus ilex L. – accepted – holly oak
  Quercus nigra L. – accepted – water oak
  Quercus nigra var. marilandica L. – not accepted
  Quercus phellos L. – accepted – willow oak
  Quercus prinus L. – not accepted
  Quercus prinus L. – not accepted – chestnut oak
  Quercus robur L. – accepted – English oak
  Quercus rubra L. – accepted – northern red oak
  Quercus rubra var. rubra L. – not accepted – northern red oak
  Quercus suber L. – accepted – cork oak
  Quisqualis L. – accepted – Rangoon creeper
  Quisqualis indica L. – not accepted – Rangoon creeper
  Rajania L. – accepted – rajania
  Rajania cordata L. – accepted – himber
  Randia L. – accepted – indigoberry
  Randia aculeata L. – accepted – white indigoberry
  Randia mitis L. – not accepted
  Ranunculus L. – accepted – renoncules, buttercup
  Ranunculus abortivus L. – accepted – kidney-leaf buttercup, early woodbuttercup, smallflower buttercup, smallflower crowfoot, littleleaf buttercup
  Ranunculus abortivus var. abortivus L. – not accepted – littleleaf buttercup
  Ranunculus aconitifolius L. – accepted
  Ranunculus acris L. – accepted – meadow buttercup, tall buttercup
  Ranunculus acris var. acris L. – not accepted – tall buttercup, meadow buttercup, showy buttercup
  Ranunculus aquatilis L. – accepted – whitewater crowfoot, water buttercup, white water crowfoot
  Ranunculus aquatilis var. aquatilis L. – accepted – white water crowfoot
  Ranunculus arvensis L. – accepted – corn buttercup
  Ranunculus auricomus L. – accepted – Greenland buttercup
  Ranunculus auricomus var. auricomus L. – not accepted – Greenland buttercup
  Ranunculus bulbosus L. – accepted – blister flower, bulbous buttercup, bulbous crowfoot, gowan, yellow weed, St. Anthony's turnip
  Ranunculus ficaria L. – accepted – fig buttercup
  Ranunculus ficaria var. ficaria L. – not accepted – fig buttercup
  Ranunculus flammula L. – accepted – spearwort buttercup, greater creeping spearwort
  Ranunculus flammula var. flammula L. – accepted – flame buttercup, greater creeping spearwort
  Ranunculus glacialis L. – accepted – glacier buttercup
  Ranunculus glacialis var. genuinus L. – not accepted
  Ranunculus glacialis var. glacialis L. – accepted – glacier buttercup
  Ranunculus gramineus L. – accepted
  Ranunculus hederaceus L. – accepted – ivy buttercup
  Ranunculus lapponicus L. – accepted – Lapland buttercup
  Ranunculus muricatus L. – accepted – spinyfruit buttercup
  Ranunculus nivalis L. – accepted – snow buttercup
  Ranunculus parviflorus L. – accepted – sticktight buttercup, smallflower buttercup
  Ranunculus parvulus L. – not accepted
  Ranunculus repens L. – accepted – creeping buttercup
  Ranunculus repens var. repens L. – not accepted – creeping buttercup
  Ranunculus reptans L. – not accepted
  Ranunculus sceleratus L. – accepted – celeryleaf buttercup, cursed buttercup
  Ranunculus sceleratus var. sceleratus L. – accepted – cursed buttercup
  Ranunculus sceleratus var. scleratus L. – not accepted
  Raphanus L. – accepted – radish
  Raphanus raphanistrum L. – accepted – wild radish
  Raphanus sativus L. – accepted – cultivated radish, radish, garden radish, wild radish
  Rauvolfia L. – accepted – devil's-pepper
  Rauvolfia canescens L. – not accepted
  Rauvolfia tetraphylla L. – accepted – devil's-pepper, four-leaf devil's-pepper, milkbush, be still tree
  Renealmia recurvata L. – not accepted
  Renealmia usneoides L. – not accepted
  Reseda L. – accepted – mignonette
  Reseda alba L. – accepted – white upright mignonette
  Reseda lutea L. – accepted – wild mignonette, yellow mignonette
  Reseda luteola L. – accepted – weld, dyer's-rocket, gualda
  Reseda odorata L. – accepted – garden mignonette
  Reseda phyteuma L. – accepted – rampion mignonette
  Rhacoma crossopetalum L. – not accepted
  Rhamnus L. – accepted – buckthorn
  Rhamnus alaternus L. – accepted – Italian buckthorn
  Rhamnus cathartica L. – accepted – Carolina buckthorn, European buckthorn, European waythorn, Hart's thorn, nerprun cathartique, common buckthorn
  Rhamnus frangula L. – accepted – glossy buckthorn, columnar buckthorn, European alder, fen buckthorn, tall hedge buckthorn, alder buckthorn
  Rhamnus infectoria L. – not accepted
  Rhamnus lycioides L. – accepted
  Rhamnus oleoides L. – not accepted
  Rhamnus paliurus L. – not accepted
  Rhamnus tinctoria L. – not accepted
  Rheedia L. – not accepted
  Rheedia lateriflora L. – not accepted
  Rheum L. – accepted – rhubarb
  Rheum palmatum L. – accepted – Chinese rhubarb
  Rheum rhabarbarum L. – accepted – garden rhubarb
  Rheum rhaponticum L. – accepted – false rhubarb
  Rhexia L. – accepted – meadowbeauty
  Rhexia mariana L. – accepted – Maryland meadowbeauty
  Rhexia mariana var. mariana L. – accepted – Maryland meadowbeauty
  Rhexia virginica L. – accepted – common meadowbeauty, handsome Harry
  Rhinanthus L. – accepted – yellow rattle, rattleweed
  Rhinanthus crista-galli L. – not accepted
  Rhinanthus major L. – accepted – European yellow rattle
  Rhinanthus minor L. – accepted – little yellow-rattle, little yellowrattle, little yellow rattle
  Rhinanthus minor ssp. minor L. – accepted – cockscomb rhinanthus, little yellowrattle, little yellow rattle
  Rhizophora L. – accepted – mangrove
  Rhizophora gymnorhiza L. – not accepted
  Rhizophora mangle L. – accepted – American mangrove, red mangrove
  Rhodiola L. – accepted – stonecrop
  Rhodiola rosea L. – accepted – roseroot stonecrop
  Rhododendron L. – accepted – azaleas, rhododendron
  Rhododendron ferrugineum L. – accepted – alpine-rose, alpenrose
  Rhododendron maximum L. – accepted – rosebay rhododendron, rosebay, great laurel
  Rhodora canadensis L. – not accepted
  Rhus L. – accepted – sumac
  Rhus copallina L. – not accepted – shining sumac, dwarf sumac
  Rhus copallina var. copallina L. – not accepted
  Rhus copallinum L. – accepted – flameleaf sumac, winged sumac, shining sumac
  Rhus copallinum var. copallinum L. – accepted – winged sumac, shining sumac, flameleaf sumac
  Rhus coriaria L. – accepted – Sicilian sumac
  Rhus cotinus L. – not accepted
  Rhus glabra L. – accepted – sumac glabre, smooth sumac
  Rhus radicans L. – not accepted – poison ivy
  Rhus succedanea L. – not accepted
  Rhus toxicodendron L. – not accepted
  Rhus typhina L. – accepted – staghorn sumac
  Rhus vernix L. – not accepted – poison sumac, sumac à vernis
  Ribes L. – accepted – currant
  Ribes alpinum L. – accepted – alpine currant
  Ribes cynosbati L. – accepted – eastern prickly gooseberry, pasture currant
  Ribes grossularia L. – not accepted
  Ribes nigrum L. – accepted – European black currant
  Ribes oxyacanthoides L. – accepted – Canadian gooseberry
  Ribes oxyacanthoides ssp. oxyacanthoides L. – not accepted – Canadian gooseberry
  Ribes oxyacanthoides var. oxyacanthoides L. – accepted – Canadian gooseberry
  Ribes rubrum L. – accepted – cultivated currant
  Ribes uva-crispa L. – accepted – European gooseberry
  Ribes uva-crispa var. uva-crispa L. – not accepted – European gooseberry
  Riccia L. – accepted
  Riccia crystallina L. – accepted
  Riccia fluitans L. – accepted
  Riccia glauca L. – accepted
  Riccia glauca var. glauca L. – accepted
  Richardia L. – not accepted
  Richardia L. – accepted – Mexican clover
  Richardia scabra L. – accepted – rough Mexican clover
  Ricinus L. – accepted
  Ricinus communis L. – accepted – castor bean, agaliya, lama palagi, maskerekur, toto ni vavalagi, uluchula skoki, castorbean
  Rivina L. – accepted
  Rivina humilis L. – accepted – bloodberry rougeplant, rougeplant
  Rivina octandra L. – not accepted
  Robinia L. – accepted – locust
  Robinia grandiflora L. – not accepted
  Robinia hispida L. – accepted – bristly locust, rose acacia
  Robinia hispida var. hispida L. – accepted – bristly locust
  Robinia pseudo-acacia L. – not accepted – black locust
  Robinia pseudoacacia L. – accepted – black locust, false acacia, yellow locust
  Rondeletia L. – not accepted
  Rondeletia L. – accepted – cordobancillo
  Rondeletia repens L. – not accepted
  Rosa L. – accepted – wildrose, rose
  Rosa canina L. – accepted – dog rose
  Rosa carolina L. – accepted – Carolina rose
  Rosa carolina ssp. carolina L. – accepted
  Rosa carolina var. carolina L. – not accepted – Carolina rose
  Rosa centifolia L. – not accepted – cabbage rose
  Rosa centifolia var. centifolia L. – not accepted – cabbage rose
  Rosa cinnamomea L. – accepted – cinnamon rose
  Rosa eglanteria L. – not accepted – sweetbriar rose
  Rosa gallica L. – accepted – apothecary rose, Hungarian rose, officinal rose, French rose
  Rosa gallica var. gallica L. – not accepted – French rose
  Rosa gallica var. versicolor L. – not accepted
  Rosa indica L. – accepted – cyme rose
  Rosa pendulina L. – accepted – mountain rose, alpine rose
  Rosa pimpinellifolia L. – not accepted
  Rosa rubiginosa L. – accepted – sweetbriar rose
  Rosa rubiginosa var. rubiginosa L. – accepted – sweetbriar rose
  Rosa sempervirens L. – accepted – evergreen rose
  Rosa spinosissima L. – accepted – Burnet rose, Scotchbriar, Scotch rose
  Rosa villosa L. – accepted – apple rose
  Rosmarinus L. – accepted – rosemary
  Rosmarinus officinalis L. – accepted – rosemary, romero
  Rotala L. – accepted
  Rubia L. – accepted
  Rubia peregrina L. – accepted
  Rubia tinctoria L. – not accepted – dyer's madder, Indian madder, madder
  Rubia tinctorum L. – accepted – madder, Indian madder, dyer's madder
  Rubus L. – accepted – framboises, ronces, brambles, blackberry
  Rubus arcticus L. – accepted – arctic blackberry
  Rubus arcticus ssp. arcticus L. – accepted – arctic blackberry
  Rubus caesius L. – accepted – European dewberry
  Rubus canadensis L. – accepted – smooth blackberry
  Rubus chamaemorus L. – accepted – cloudberry
  Rubus dalibarda L. – not accepted
  Rubus fruticosus L. – not accepted – bramble blackberry, wild blackberry complex, shrubby blackberry
  Rubus hispidus L. – accepted – bristly dewberry
  Rubus idaeus L. – accepted – common red raspberry, western red raspberry, American red raspberry
  Rubus idaeus ssp. idaeus L. – not accepted – American red raspberry
  Rubus idaeus var. idaeus L. – accepted – European red raspberry
  Rubus japonicus L. – not accepted
  Rubus moluccanus L. – accepted – kohkihl, Molucca bramble, Molucca raspberry, soni, wa ngandrongandro, wild raspberry, wild blackberry, eelkek
  Rubus occidentalis L. – accepted – black raspberry
  Rubus odoratus L. – accepted – purpleflowering raspberry
  Rubus odoratus var. odoratus L. – not accepted – purpleflowering raspberry
  Rubus parvifolius L. – accepted – threeleaf blackberry
  Rubus saxatilis L. – accepted – Greenland thornless blackberry
  Rudbeckia L. – accepted – coneflower
  Rudbeckia hirta L. – accepted – blackeyed Susan, black-eyed Susan
  Rudbeckia hirta var. hirta L. – accepted – blackeyed Susan
  Rudbeckia laciniata L. – accepted – cutleaf coneflower, green-head coneflower
  Rudbeckia laciniata var. laciniata L. – accepted – cutleaf coneflower
  Rudbeckia purpurea L. – not accepted
  Rudbeckia triloba L. – accepted – browneyed Susan
  Rudbeckia triloba var. triloba L. – accepted – browneyed Susan
  Ruellia L. – accepted – wild petunia
  Ruellia antipoda L. – not accepted
  Ruellia blechum L. – accepted – Browne's blechum
  Ruellia strepens L. – accepted – limestone wild petunia
  Ruellia tuberosa L. – accepted – minnieroot
  Rumex L. – accepted – dock
  Rumex acetosa L. – accepted – garden sorrel
  Rumex acetosa ssp. acetosa L. – not accepted – garden sorrel
  Rumex acetosella L. – accepted – sheep sorrel, field sorrel, red sorrel, common sheep sorrel
  Rumex alpinus L. – accepted – Munk's rhubarb
  Rumex aquaticus L. – accepted – western dock
  Rumex britannica L. – accepted – greater water dock
  Rumex bucephalophorus L. – accepted – red dock
  Rumex crispus L. – accepted – curly dock, narrowleaf dock, sour dock, yellow dock
  Rumex crispus ssp. crispus L. – not accepted – curly dock, narrowleaf dock, sour dock, yellow dock
  Rumex dentatus L. – accepted – toothed dock
  Rumex dentatus var. dentatus L. – not accepted
  Rumex digyna L. – not accepted
  Rumex digynus L. – not accepted
  Rumex maritimus L. – accepted – bristle dock, golden dock
  Rumex obtusifolius L. – accepted – bluntleaf dock, bitter dock
  Rumex obtusifolius var. obtusifolius L. – not accepted
  Rumex patientia L. – accepted – patience dock
  Rumex persicarioides L. – accepted
  Rumex pulcher L. – accepted – fiddle dock
  Rumex pulcher var. pulcher L. – not accepted
  Rumex sanguineus L. – accepted – redvein dock
  Rumex scutatus L. – accepted – French sorrel
  Rumex spinosus L. – not accepted
  Rumex verticillatus L. – accepted – swamp dock
  Rumex vesicarius L. – accepted
  Ruppia L. – accepted – widgeonweed
  Ruppia maritima L. – accepted – widgeongrass, widgeon-grass
  Ruppia maritima var. maritima L. – not accepted – widgeonweed
  Ruta L. – accepted – rue
  Ruta chalepensis L. – accepted – fringed rue
  Ruta graveolens L. – accepted – common rue
  Saccharum L. – accepted – sugarcane, sugar cane
  Saccharum officinarum L. – accepted – sugarcane
  Saccharum officinarum var. officinarum L. – not accepted
  Saccharum spontaneum L. – accepted – wild sugarcane, ahlek, loa, wild cane
  Saccharum spontaneum var. spontaneum L. – not accepted
  Sagina L. – accepted – pearlwort
  Sagina procumbens L. – accepted – birdeye pearlwort, birdseye pearlwort, procumbent pearlwort
  Sagina virginica L. – not accepted
  Sagittaria L. – accepted – arrowhead
  Sagittaria lancifolia L. – accepted – bulltongue, scythefruit arrowhead, bulltongue arrowhead
  Sagittaria lancifolia ssp. lancifolia L. – accepted – bulltongue arrowhead
  Sagittaria obtusifolia L. – not accepted
  Sagittaria obtusifolium L. – not accepted
  Sagittaria sagittifolia L. – not accepted – arrowhead, Hawaii arrowhead
  Sagittaria trifolia L. – accepted – threeleaf arrowhead
  Sagittaria trifolia ssp. trifolia L. – accepted
  Salacia L. – accepted
  Salacia chinensis L. – accepted
  Salicornia L. – accepted – glasswort, pickleweed
  Salicornia fruticosum L. – not accepted
  Salicornia virginica L. – not accepted – Virginia glasswort
  Salix L. – accepted – saule, saules, willow
  Salix aegyptiaca L. – accepted
  Salix alba L. – accepted – golden willow, white willow
  Salix alba var. alba L. – not accepted – white willow
  Salix aurita L. – accepted – eared willow
  Salix babylonica L. – accepted – weeping willow
  Salix caprea L. – accepted – goat willow
  Salix cinerea L. – accepted – large gray willow
  Salix cinerea ssp. cinerea L. – not accepted – large gray willow
  Salix fragilis L. – accepted – crack willow
  Salix glauca L. – accepted – grayleaf willow
  Salix glauca ssp. glauca L. – not accepted – grayleaf willow
  Salix glauca ssp. glauca var. glauca L. – not accepted
  Salix glauca var. glauca L. – accepted – grayleaf willow
  Salix hastata L. – accepted – halberd willow
  Salix herbacea L. – accepted – snowbed willow
  Salix lanata L. – accepted – woolly willow
  Salix lapponum L. – accepted – Lapland willow, downy willow
  Salix myrsinites L. – accepted – myrtle willow
  Salix pentandra L. – accepted – bay-leaf willow, laurel willow
  Salix purpurea L. – accepted – purple willow, basket willow, purple osier
  Salix repens L. – accepted – creeping willow
  Salix reticulata L. – accepted – netted willow, netleaf willow
  Salix reticulata ssp. reticulata L. – not accepted – netleaf willow
  Salix rosmarinifolia L. – accepted
  Salix triandra L. – accepted – French willow, almond-leaf willow, almond willow
  Salix viminalis L. – accepted – basket willow
  Salix vitellina L. – not accepted
  Salsola L. – accepted – tumbleweed, Russian thistle
  Salsola kali L. – accepted – tumbleweed, prickly Russian thistle, Russian thistle
  Salsola kali ssp. kali L. – accepted – tumbleweed, Russian thistle
  Salsola soda L. – accepted – oppositeleaf Russian thistle
  Salsola tragus L. – accepted – prickly Russian thistle, tumbleweed
  Salsola vermiculata L. – accepted – wormleaf salsola, shrubby Russian thistle
  Salvia L. – accepted – sage
  Salvia aethiopis L. – accepted – African sage, Mediterranean sage
  Salvia argentea L. – accepted – silver sage
  Salvia aurea L. – accepted
  Salvia dominica L. – accepted
  Salvia glutinosa L. – accepted – sticky sage
  Salvia hispanica L. – accepted – chia
  Salvia indica L. – accepted
  Salvia lyrata L. – accepted – lyreleaf sage
  Salvia nemorosa L. – not accepted – woodland sage
  Salvia nutans L. – accepted – nodding sage
  Salvia officinalis L. – accepted – kitchen sage
  Salvia pinnata L. – accepted
  Salvia pratensis L. – accepted – introduced sage
  Salvia sclarea L. – accepted – salvia romana, clary, clary sage, Europe sage
  Salvia serotina L. – accepted – littlewoman
  Salvia spinosa L. – accepted
  Salvia sylvestris L. – accepted – woodland sage
  Salvia syriaca L. – accepted
  Salvia urticifolia L. – accepted – nettleleaf sage
  Salvia verbenaca L. – accepted – wild sage, wild clary, vervain sage
  Salvia verbenacea L. – not accepted
  Salvia verticillata L. – accepted – lilac sage
  Salvia viridis L. – accepted – wild clary, annual clary, bluebeard
  Sambucus L. – accepted – elderberry
  Sambucus canadensis L. – not accepted – American elder
  Sambucus canadensis var. canadensis L. – not accepted
  Sambucus ebulus L. – accepted – dwarf elder, dwarf elderberry
  Sambucus nigra L. – accepted – European black elder, European elderberry, European black elderberry, elder, elderberry, common elderberry, black elderberry
  Sambucus nigra ssp. nigra L. – accepted – European black elderberry
  Sambucus nigra var. laciniata L. – not accepted
  Sambucus racemosa L. – accepted – European red elder, scarlet elderberry, red elderberry
  Sambucus racemosa ssp. racemosa L. – accepted – European red elderberry
  Sambucus racemosa var. racemosa L. – accepted – red elderberry, bunchberry elder
  Samolus L. – accepted – waterpimpernel, brookweed
  Samolus valerandi L. – accepted – seaside brookweed
  Samolus valerandi ssp. valerandi L. – not accepted – seaside brookweed
  Samyda guidonia L. – not accepted
  Sanguinaria L. – accepted – bloodroot
  Sanguinaria canadensis L. – accepted – bloodroot
  Sanguisorba L. – accepted – burnet
  Sanguisorba canadensis L. – accepted – Canadian burnet
  Sanguisorba officinalis L. – accepted – official burnet
  Sanicula L. – accepted – sanicle
  Sanicula canadensis L. – accepted – Canada sanicle, Canadian blacksnakeroot
  Sanicula canadensis var. canadensis L. – accepted – sanicle du Canada variété du Canada, Canadian blacksnakeroot
  Sanicula marilandica L. – accepted – black sanicle, Maryland black-snakeroot, Maryland sanicle
  Santalum L. – accepted – sandalwood
  Santalum album L. – accepted – sandalwood
  Santolina L. – accepted – lavender cotton
  Santolina chamaecyparissus L. – accepted – lavender cotton
  Santolina rosmarinifolia L. – accepted
  Sapindus L. – accepted – soapberry
  Sapindus saponaria L. – accepted – western soapberry, wingleaf soapberry
  Sapindus saponaria var. saponaria L. – accepted – wingleaf soapberry
  Sapindus trifoliatus L. – accepted – threeleaf soapberry
  Saponaria L. – accepted – soapwort
  Saponaria ocymoides L. – accepted – rock soapwort
  Saponaria officinalis L. – accepted – soapwort, bouncingbet, bouncingbet soapweed, bouncing bet, sweet Betty
  Saponaria porrigens L. – not accepted
  Saponaria vaccaria L. – not accepted
  Sarothra gentianoides L. – not accepted
  Sarracenia L. – accepted – pitcherplant
  Sarracenia flava L. – accepted – yellow pitcherplant
  Sarracenia flava var. flava L. – accepted
  Sarracenia purpurea L. – accepted – pitcherplant, purple pitcherplant, sidesaddle-flower, frog's-britches, huntsman's-horns
  Sarracenia purpurea f. purpurea L. – accepted
  Sarracenia purpurea ssp. purpurea L. – accepted – purple pitcherplant
  Sarracenia purpurea ssp. purpurea var. purpurea L. – not accepted
  Sarracenia purpurea var. purpurea L. – not accepted – purple pitcherplant
  Satureja L. – accepted – savory
  Satureja hortensis L. – accepted – summer savory
  Satureja montana L. – accepted – winter savory
  Satureja viminea L. – not accepted – serpentine savory
  Saururus L. – accepted
  Saururus cernuus L. – accepted – lézardelle penchée, lizard's tail
  Saururus natans L. – not accepted
  Sauvagesia L. – accepted
  Sauvagesia erecta L. – accepted – creole tea
  Saxifraga L. – accepted – saxifrage
  Saxifraga adscendens L. – accepted – wedgeleaf saxifrage, rock saxifrage
  Saxifraga aizoides L. – accepted – evergreen saxifrage, yellow mountain saxifrage
  Saxifraga bronchialis L. – accepted – spotted saxifrage, yellowdot saxifrage
  Saxifraga bronchialis ssp. bronchialis L. – accepted – yellowdot saxifrage
  Saxifraga caespitosa L. – not accepted – tufted alpine saxifrage
  Saxifraga caespitosa ssp. caespitosa L. – not accepted – tufted alpine saxifrage
  Saxifraga cernua L. – accepted – nodding saxifrage
  Saxifraga cespitosa L. – accepted – tufted alpine saxifrage, tufted saxifrage
  Saxifraga cespitosa ssp. cespitosa L. – not accepted – tufted alpine saxifrage
  Saxifraga cespitosa ssp. cespitosa var. cespitosa L. – not accepted – tufted alpine saxifrage
  Saxifraga hirculus L. – accepted – yellow marsh saxifrage
  Saxifraga hirculus ssp. hirculus L. – not accepted – yellow marsh saxifrage
  Saxifraga hirsuta L. – accepted – kidney saxifrage
  Saxifraga nivalis L. – not accepted – alpine saxifrage
  Saxifraga oppositifolia L. – accepted – purple mountain saxifrage, purple saxifrage
  Saxifraga oppositifolia ssp. oppositifolia L. – accepted – purple mountain saxifrage
  Saxifraga pensylvanica L. – not accepted – eastern swamp saxifrage
  Saxifraga pensylvanica var. pensylvanica L. – not accepted
  Saxifraga punctata L. – not accepted
  Saxifraga punctata var. punctata L. – not accepted
  Saxifraga rivularis L. – accepted – weak saxifrage, alpine brook saxifrage, pygmy saxifrage
  Saxifraga rivularis ssp. rivularis L. – accepted – weak saxifrage, alpine brook saxifrage
  Saxifraga sibirica L. – accepted – bract saxifrage
  Saxifraga stellaris L. – not accepted – starry saxifrage
  Saxifraga tridactylites L. – accepted – rueleaf saxifrage
  Saxifraga umbrosa L. – accepted – Pyrenees saxifrage
  Scabiosa L. – accepted – pincushions
  Scabiosa arvensis L. – not accepted
  Scabiosa atropurpurea L. – accepted – mourningbride
  Scabiosa columbaria L. – accepted – dove pincushions
  Scabiosa ochroleuca L. – accepted – cream pincushions
  Scabiosa palaestina L. – not accepted
  Scabiosa palaestrina L. – not accepted
  Scabiosa stellata L. – not accepted – starflower pincushions
  Scabiosa succisa L. – not accepted
  Scaevola L. – accepted – naupaka
  Scandix L. – accepted
  Scandix cerefolium L. – not accepted
  Scandix pecten-veneris L. – accepted – shepherd's needle, shepherdsneedle
  Scheuchzeria L. – accepted – Rannoch-rush
  Scheuchzeria palustris L. – accepted – Rannoch-rush
  Scheuchzeria palustris var. palustris L. – not accepted
  Schinus L. – accepted – peppertree
  Schinus molle L. – accepted – peppertree, American pepper, escobilla, false pepper, molle del Peru, pepper tree, Peruvian peppertree
  Schoenus L. – accepted – bogrush
  Schoenus coloratus L. – not accepted
  Schoenus ferrugineus L. – accepted – rusty bogrush
  Schoenus nigricans L. – accepted – black bog rush, black bogrush
  Schwalbea L. – accepted
  Schwalbea americana L. – accepted – American chaffseed, chaffseed
  Scilla L. – accepted – scilla
  Scirpus L. – accepted – bulrushes, bulrush
  Scirpus autumnalis L. – not accepted
  Scirpus caespitosus L. – not accepted
  Scirpus capillaris L. – not accepted
  Scirpus cespitosus L. – not accepted
  Scirpus corymbosus L. – not accepted
  Scirpus dichotomus L. – not accepted
  Scirpus ferrugineus L. – not accepted
  Scirpus fluitans L. – not accepted
  Scirpus geniculatus L. – not accepted
  Scirpus holoschoenus L. – not accepted
  Scirpus lacustris L. – not accepted
  Scirpus lithospermus L. – not accepted
  Scirpus maritimus L. – not accepted
  Scirpus miliaceus L. – not accepted
  Scirpus mucronatus L. – not accepted
  Scirpus mutatus L. – not accepted
  Scirpus palustris L. – not accepted
  Scirpus retrofractus L. – not accepted
  Scirpus setaceus L. – not accepted
  Scirpus sylvaticus L. – accepted
  Scirpus triqueter L. – not accepted
  Scleranthus L. – accepted – German knotgrass
  Scleranthus annuus L. – accepted – knawel, German knotgrass
  Scleranthus annuus ssp. annuus L. – accepted – knawel
  Scleranthus perennis L. – accepted – perennial knawel
  Scleranthus perennis ssp. perennis L. – accepted – perennial knawel
  Scolymus L. – accepted – goldenthistle
  Scolymus hispanica L. – not accepted
  Scolymus hispanicus L. – accepted – common goldenthistle, golden thistle
  Scolymus maculatus L. – accepted – spotted goldenthistle
  Scoparia L. – accepted – licorice weed
  Scoparia dulcis L. – accepted – licorice weed
  Scorpiurus L. – accepted – scorpion's-tail
  Scorpiurus muricatus L. – accepted – prickly scorpion's-tail
  Scorpiurus subvillosus L. – not accepted
  Scorpiurus sulcatus L. – not accepted
  Scorpiurus vermiculatus L. – accepted
  Scorzonera L. – accepted – scorzonera
  Scorzonera hispanica L. – accepted – black salsify
  Scorzonera hispanicus L. – not accepted
  Scorzonera laciniata L. – accepted – cutleaf vipergrass
  Scrophularia L. – accepted – figwort
  Scrophularia aquatica L. – not accepted
  Scrophularia auriculata L. – accepted – shoreline figwort
  Scrophularia canina L. – accepted – dog figwort
  Scrophularia canina ssp. canina L. – accepted – dog figwort
  Scrophularia marilandica L. – accepted – carpenter's square, Maryland figwort
  Scrophularia nodosa L. – accepted – woodland figwort
  Scrophularia peregrina L. – accepted – Mediterranean figwort
  Scutellaria L. – accepted – Huachuca skullcap, skullcap
  Scutellaria altissima L. – accepted – tall skullcap
  Scutellaria galericulata L. – accepted – hooded skullcap, marsh skullcap
  Scutellaria integrifolia L. – accepted – helmet flower
  Scutellaria lateriflora L. – accepted – mad dog skullcap, blue skullcap
  Scutellaria lateriflora var. lateriflora L. – accepted – blue skullcap
  Secale L. – accepted – rye
  Secale cereale L. – accepted – cultivated rye, rye, common rye, cereal rye, cultivated annual rye
  Secale orientale L. – not accepted
  Secale villosum L. – not accepted
  Securidaca L. – accepted
  Securidaca volubilis L. – not accepted
  Sedum L. – accepted – stonecrop
  Sedum acre L. – accepted – orpin acre, goldmoss stonecrop
  Sedum aizoon L. – not accepted – fei cai, Aizoon stonecrop
  Sedum album L. – accepted – white stonecrop
  Sedum annuum L. – accepted – annual stonecrop
  Sedum dasyphyllum L. – accepted – thick-leaf stonecrop
  Sedum hispanicum L. – accepted – orpin d'Espagne, Spanish stonecrop
  Sedum hybridum L. – not accepted – hybrid stonecrop
  Sedum reflexum L. – not accepted – Jenny's stonecrop
  Sedum rupestre L. – accepted – reflexed stonecrop, Jenny's stonecrop
  Sedum sexangulare L. – accepted – tasteless stonecrop
  Sedum telephium L. – not accepted – witch's moneybags
  Sedum telephium ssp. telephium L. – not accepted – witch's moneybags
  Sedum villosum L. – accepted – orpin velu, purple stonecrop
  Selinum L. – accepted
  Selinum monnieri L. – not accepted
  Sempervivum L. – accepted – houseleek
  Sempervivum tectorum L. – accepted – common houseleek
  Senecio L. – accepted – ragwort, groundsel
  Senecio aureus L. – not accepted – golden ragwort
  Senecio elegans L. – accepted – redpurple ragwort
  Senecio erucifolius L. – not accepted – hoary ragwort
  Senecio hieraciifolia L. – not accepted
  Senecio hieraciifolius L. – not accepted
  Senecio jacobaea L. – not accepted – stinking willie, tansy ragwort, ragwort
  Senecio squalidus L. – accepted – Oxford ragwort
  Senecio sylvatica L. – not accepted
  Senecio sylvaticus L. – accepted – woodland ragwort
  Senecio viscosus L. – accepted – sticky ragwort
  Senecio vulgaris L. – accepted – old-man-in-the-spring, common groundsel
  Serapias helleborine L. – not accepted
  Serratula L. – accepted – plumeless saw-wort
  Serratula alpina L. – not accepted
  Serratula arvensis L. – not accepted
  Serratula tinctoria L. – accepted – Dyer's plumeless saw-wort
  Sesamum L. – accepted – sesame
  Sesamum indicum L. – accepted – sesame
  Sesamum orientale L. – not accepted – sesame
  Seseli L. – accepted
  Sesuvium L. – accepted – sea purslane, seapurslane
  Sherardia L. – accepted
  Sherardia arvensis L. – accepted – blue fieldmadder, blue field-madder, field madder
  Sibbaldia L. – accepted
  Sibbaldia erecta L. – not accepted
  Sibbaldia procumbens L. – accepted – creeping sibbaldia, creeping-glow-wort, prostrate sibbaldia
  Sicyos L. – accepted – bur cucumber
  Sicyos angulatus L. – accepted – bur cucumber, wall bur cucumber, oneseed bur cucumber, sicyos anguleux, nimble-Kate, star cucumber
  Sicyos laciniatus L. – accepted – cutleaf bur cucumber
  Sicyos trifoliatus L. – not accepted
  Sida L. – not accepted
  Sida L. – accepted – fanpetals
  Sida abutilon L. – not accepted
  Sida alaba L. – not accepted
  Sida alba L. – not accepted
  Sida alnifolia L. – not accepted
  Sida capitata L. – not accepted
  Sida ciliaris L. – accepted – bracted sida, bracted fanpetals, fringed sida, salmon sida
  Sida cordifolia L. – accepted – `ilima, great-leaved sida
  Sida crispa L. – not accepted
  Sida cristata L. – not accepted
  Sida jamaicensis L. – accepted – Jamaican fanpetals
  Sida paniculata L. – not accepted
  Sida periplocifolia L. – not accepted
  Sida rhombifolia L. – accepted – arrowleaf sida, Cuban-jute, Cuban jute, Cuba jute, escobilla, axocatzín, huinar
  Sida rhombifolia var. rhombifolia L. – not accepted
  Sida spinosa L. – accepted – prickly sida, prickly fanpetals, false mallow, Indian mallow, prickly mallow
  Sida umbellata L. – not accepted
  Sida urens L. – accepted – tropical fanpetals, bristly sida
  Sida viscosa L. – not accepted
  Sideritis L. – accepted – ironwort
  Sideritis lanata L. – accepted – hairy ironwort
  Sideritis montana L. – accepted – mountain ironwort
  Sideritis romana L. – accepted – simplebeak ironwort
  Sideroxylon L. – accepted – bumelia, bully
  Sideroxylon lycioides L. – accepted – buckthorn bully
  Sideroxylon tenax L. – accepted – tough bully
  Sigesbeckia L. – accepted – St. Paul's wort
  Sigesbeckia orientalis L. – accepted – common St. Paul's wort
  Silene L. – accepted – silènes, campion, catchfly
  Silene anglica L. – not accepted
  Silene antirrhina L. – accepted – catchfly, sleepy catchfly, sleepy campion, sleepy silene
  Silene armeria L. – accepted – sweet William silene
  Silene conica L. – accepted – striped corn catchfly
  Silene conica ssp. conica L. – accepted – striped corn catchfly
  Silene conoidea L. – accepted – cone catchfly, weed campion, weed silene
  Silene gallica L. – accepted – windmill catchfly, common catchfly
  Silene inaperta L. – accepted
  Silene noctiflora L. – accepted – night-flowering catchfly, sticky cockle, nightflowering silene
  Silene nocturna L. – accepted
  Silene nocturum L. – not accepted
  Silene nutans L. – accepted – Eurasian catchfly
  Silene pendula L. – accepted – nodding catchfly
  Silene rupestris L. – accepted
  Silene virginica L. – accepted – firepink, fire pink
  Silene virginica var. virginica L. – not accepted – fire pink
  Silphium L. – accepted – rosinweed
  Silphium asteriscus L. – accepted – starry rosinweed
  Silphium asteriscus var. asteriscus L. – accepted – starry rosinweed, roughleaf rosinweed
  Silphium connatum L. – not accepted
  Silphium laciniatum L. – accepted – compassplant, compass plant
  Silphium laciniatum var. laciniatum L. – not accepted – compassplant
  Silphium perfoliatum L. – accepted – cup plant, cup-plant, cupleaf rosinweed, squarestem rosinweed
  Silphium perfoliatum var. perfoliatum L. – accepted – cup plant
  Silphium trifoliatum L. – accepted – whorled rosinweed
  Silphium trifoliatum var. trifoliatum L. – not accepted – whorled rosinweed
  Silphium trilobatum L. – not accepted
  Sinapis L. – accepted – mustard
  Sinapis alba L. – accepted – white mustard
  Sinapis arvensis L. – accepted – charlock, corn mustard, corn-mustard, wild mustard, charlock mustard
  Sinapis arvensis ssp. arvensis L. – not accepted – wild mustard, California rape, charlock, collejón
  Sinapis incana L. – not accepted
  Sinapis juncea L. – not accepted
  Sinapis nigra L. – not accepted
  Siphonanthus indicus L. – not accepted
  Sisymbrium L. – accepted – hedge mustard, hedgemustard
  Sisymbrium altissimum L. – accepted – tall hedge-mustard, tumblemustard, Jim Hill mustard, tall mustard, tumble mustard, tumbleweed mustard, tall tumblemustard
  Sisymbrium amphibium L. – not accepted
  Sisymbrium indicum L. – not accepted
  Sisymbrium irio L. – accepted – rocketmustard, London rocket
  Sisymbrium loeselii L. – accepted – false London rocket, tallhedge mustard, tall hedgemustard, small tumbleweed mustard
  Sisymbrium murale L. – not accepted
  Sisymbrium nasturtium-aquaticum L. – not accepted
  Sisymbrium orientale L. – accepted – Indian hedge-mustard, oriental hedgemustard, Indian hedgemustard
  Sisymbrium polyceratium L. – accepted – shortfruit hedgemustard
  Sisymbrium sophia L. – not accepted
  Sisymbrium tenuifolium L. – not accepted
  Sisyrinchium L. – accepted – blueeyed grass, blue-eyed grass
  Sium L. – accepted – water parsnip, waterparsnip
  Sium angustifolium L. – not accepted
  Sium latifolium L. – accepted – wideleaf waterparsnip
  Sium sisarum L. – accepted – skirret
  Sloanea L. – accepted – bullwood
  Smilax L. – accepted – common greenbriar, greenbriar, sarsaparilla, catbrier, greenbrier
  Smilax aspera L. – accepted – rough bindweed
  Smilax bona-nox L. – accepted – zarzaparrilla, saw greenbrier
  Smilax china L. – accepted – China root
  Smilax herbacea L. – accepted – herbaceous greenbriar, smooth carrionflower, Jacob's lader, smilax herbacé
  Smilax lanceolata L. – not accepted
  Smilax laurifolia L. – accepted – laurel greenbrier
  Smilax pseudochina L. – accepted – bamboo vine
  Smilax rotundifolia L. – accepted – common greenbrier, greenbrier, bullbriar, common catbriar, horsebriar, roundleaf greenbriar, roundleaf greenbrier
  Smilax tamnoides L. – accepted – bristly greenbrier
  Smyrnium L. – accepted
  Smyrnium olusatrum L. – accepted – alexanders
  Solanum L. – accepted – nightshade
  Solanum aethiopicum L. – accepted – Ethiopian nightshade
  Solanum bahamense L. – accepted – Bahama nightshade
  Solanum bahamense var. bahamense L. – not accepted – Bahama nightshade
  Solanum bonariense L. – accepted
  Solanum campechiense L. – accepted – redberry nightshade
  Solanum capense L. – accepted
  Solanum carolinense L. – accepted – Carolina horsenettle, horsenettle, apple of Sodom, bull nettle, devil's tomato, sand briar
  Solanum carolinense var. carolinense L. – not accepted – Carolina horsenettle, Carolina horse-nettle, apple of Sodom, bull nettle, devil's tomato, horsenettle, sand briar
  Solanum diphyllum L. – accepted – twoleaf nightshade, twinleaf nightshade
  Solanum dulcamara L. – accepted – climbing nightshade, bitter nightshade, bittersweet nightshade, blue nightshade, European bittersweet, fellenwort, woody nightshade
  Solanum dulcamara var. dulcamara L. – not accepted – climbing nightshade, bittersweet nightshade, blue nightshade, European bittersweet, fellenwort, woody nightshade, bitter nightshade
  Solanum ferox L. – accepted – nightshade
  Solanum guineense L. – accepted
  Solanum incanum L. – accepted – nightshade
  Solanum lycopersicum L. – accepted – garden tomato
  Solanum lycopersicum var. lycopersicum L. – not accepted – garden tomato
  Solanum macrocarpon L. – accepted – nightshade
  Solanum mammosum L. – accepted – nipplefruit
  Solanum melongena L. – accepted – eggplant
  Solanum montanum L. – accepted
  Solanum nigrum L. – accepted – deadly nightshade, garden nightshade, black nightshade
  Solanum nigrum var. villosum L. – not accepted
  Solanum nigrum var. virginicum L. – not accepted
  Solanum paniculatum L. – accepted
  Solanum peruvianum L. – accepted – Peruvian nightshade
  Solanum pimpinellifolium L. – accepted – currant tomato
  Solanum pseudocapsicum L. – accepted – Jerusalem cherry
  Solanum tomentosum L. – accepted
  Solanum trilobatum L. – accepted
  Solanum tuberosum L. – accepted – Irish potato
  Solanum verbascifolium L. – not accepted
  Solanum virginianum L. – accepted – Surattense nightshade
  Solidago L. – accepted – goldenrod, verges d'or
  Solidago altissima L. – accepted – Canada goldenrod
  Solidago altissima ssp. altissima L. – accepted – late goldenrod, Canada goldenrod
  Solidago altissima var. altissima L. – not accepted
  Solidago bicolor L. – accepted – white goldenrod
  Solidago caesia L. – accepted – wreath goldenrod
  Solidago caesia var. caesia L. – accepted – wreath goldenrod
  Solidago canadensis L. – accepted – Canada goldenrod, Canadian goldenrod, common goldenrod
  Solidago canadensis var. canadensis L. – accepted – Canada goldenrod, Canadian goldenrod
  Solidago flexicaulis L. – accepted – zigzag goldenrod
  Solidago lateriflora L. – not accepted
  Solidago latifolia L. – not accepted
  Solidago mexicana L. – not accepted
  Solidago rigida L. – accepted – stiff-leaved goldenrod
  Solidago rigida ssp. rigida L. – accepted – stiff goldenrod
  Solidago sempervirens L. – accepted – seaside goldenrod
  Solidago sempervirens ssp. sempervirens L. – accepted – seaside goldenrod
  Solidago sempervirens var. sempervirens L. – not accepted – seaside goldenrod
  Sonchus L. – accepted – sowthistle, sow thistle
  Sonchus arvensis L. – accepted – field sowthistle, field sow-thistle, sowthistle, creeping sowthistle, perennial sowthistle
  Sonchus arvensis ssp. arvensis L. – accepted – field sowthistle, field sow-thistle, creeping sowthistle, perennial sowthistle
  Sonchus oleraceus L. – accepted – common sowthistle, sow-thistle, common sow-thistle, annual sowthistle, pualele, sow thistle
  Sonchus palustris L. – accepted – marsh sowthistle
  Sonchus tataricus L. – not accepted
  Sonchus tenerrimus L. – accepted – slender sowthistle
  Sophora L. – accepted – necklacepod
  Sophora japonica L. – not accepted – Japanese pagoda tree
  Sophora tomentosa L. – accepted – yellow necklacepod, yellow sophora
  Sorbus L. – accepted – mountain-ash
  Sorbus aucuparia L. – accepted – rowan, rowan-berry, European mountain-ash
  Sorbus domestica L. – accepted – servicetree
  Sorbus hybrida L. – accepted – oakleaf mountain-ash
  Sparganium L. – accepted – burreed, bur-reed
  Sparganium erectum L. – accepted – simple-stem burr-reed, branched burreed, exotic bur-reed, simplestem bur-reed
  Sparganium natans L. – accepted – small bur-reed
  Sparganium natans var. minimum L. – not accepted
  Spartium L. – accepted – broom
  Spartium junceum L. – accepted – Spanish broom, weaver's broom
  Spergula L. – accepted – spurry
  Spergula arvense var. arvense L. – not accepted – corn spurry
  Spergula arvensis L. – not accepted
  Spergula arvensis L. – accepted – field spurry, devil's gut, pickpurse, sandweed, corn spurry
  Spergula arvensis ssp. arvensis L. – not accepted – stickwort, starwort
  Spergula pentandra L. – accepted – wingstem spurry
  Spermacoce L. – accepted – false buttonweed
  Spermacoce hirta L. – not accepted
  Spermacoce tenuior L. – accepted – slender false buttonweed
  Spermacoce verticillata L. – accepted – shrubby false buttonweed
  Sphagnum L. – accepted
  Sphagnum palustre L. – accepted – prairie sphagnum
  Spigelia L. – accepted – pinkroot
  Spigelia anthelmia L. – accepted – West Indian pinkroot
  Spilanthes oleracea L. – accepted – spilanthes
  Spinacia L. – accepted – spinach
  Spinacia oleracea L. – accepted – spinach
  Spiraea L. – accepted
  Spiraea aruncus L. – not accepted
  Spiraea chamaedryfolia L. – accepted – Germander meadowsweet
  Spiraea chamaedryfolia var. chamaedryfolia L. – accepted – Germander meadowsweet
  Spiraea filipendula L. – not accepted
  Spiraea hypericifolia L. – accepted – Iberian spirea
  Spiraea opulifolia L. – not accepted
  Spiraea salicifolia L. – accepted – willowleaf meadowsweet
  Spiraea sorbifolia L. – not accepted
  Spiraea tomentosa L. – accepted – steeplebush
  Spiraea tomentosa var. tomentosa L. – not accepted – steeplebush
  Spiraea trifoliata L. – not accepted
  Spiraea trilobata L. – accepted – Asian meadowsweet
  Spiraea ulmaria L. – not accepted
  Spondias L. – accepted – mombin
  Spondias lutea L. – not accepted
  Spondias mombin L. – accepted – hogplum, yellow mombin
  Spondias purpurea L. – accepted – purple mombin
  Stachys L. – accepted – hedge nettle, hedgenettle
  Stachys cretica L. – accepted – Cretan hedgenettle
  Stachys germanica L. – accepted – German hedgenettle
  Stachys hirta L. – not accepted
  Stachys palustris L. – accepted – marsh hedgenettle
  Stachys palustris ssp. palustris L. – not accepted – woundwort
  Stachys recta L. – accepted – seaport hedgenettle, stiff hedgenettle
  Stachys sylvatica L. – accepted – whitespot
  Stapelia L. – accepted
  Stapelia hirsuta L. – accepted – carrion-flower
  Stapelia variegata L. – not accepted
  Staphylea L. – accepted – bladdernut
  Staphylea trifolia L. – accepted – American bladdernut, staphylier à trois folioles
  Statice L. – not accepted
  Statice limonium L. – not accepted
  Statice sinuata L. – not accepted
  Stellaria L. – accepted – starwort
  Stellaria biflora L. – not accepted
  Stellaria cerastioides L. – not accepted
  Stellaria cerastoides L. – not accepted
  Stellaria graminea L. – accepted – grass-leaf starwort, grassleaved stichwort, grassy starwort, little starwort, lesser starwort, grass-like starwort
  Stellaria graminea var. graminea L. – not accepted – grasslike starwort
  Stellaria holostea L. – accepted – addersmeat
  Stellaria nemorum L. – accepted – wood stitchwort
  Stellera passerina L. – not accepted
  Stemodia L. – accepted – twintip
  Stemodia maritima L. – accepted – seaside twintip
  Sterculia L. – accepted
  Sterculia foetida L. – accepted – hazel sterculia
  Stewartia L. – accepted
  Stewartia malacodendron L. – accepted – silky camellia, Virginia stewartia
  Stillingia sylvatica L. – accepted – queen's-delight
  Stillingia sylvatica ssp. sylvatica L. – not accepted – queen's-delight
  Stipa L. – accepted – needlegrass
  Stipa arguens L. – not accepted
  Stipa avenacea L. – not accepted
  Stipa avenacea var. avenacea L. – not accepted
  Stipa pennata L. – accepted
  Stipa tenacissima L. – not accepted – esparto
  Stratiotes L. – accepted – water soldiers
  Stratiotes alismoides L. – not accepted
  Stratiotes aloides L. – accepted – water soldiers, freshwater soldier, knight's pondweed, knight's woundwort, soldier plant, water aloe, water pineapple, water sengreen
  Strychnos L. – accepted
  Strychnos nux-vomica L. – accepted – strychnine tree
  Styrax L. – accepted – snowbells, snowbell
  Styrax officinalis L. – accepted – drug snowbell
  Styrax officinalis var. officinalis L. – not accepted – drug snowbell
  Subularia L. – accepted – awlwort
  Subularia aquatica L. – accepted – American awlwort, waterawlwort
  Subularia aquatica ssp. aquatica L. – accepted
  Subularia aquatica var. aquatica L. – not accepted – waterawlwort
  Suriana L. – accepted
  Suriana maritima L. – accepted – baycedar, bay-cedar, bay cedar, guitar
  Swertia L. – accepted – felwort
  Swertia perennis L. – accepted – alpinebog swertia, star gentian, felwort
  Symphytum L. – accepted – comfrey
  Symphytum officinale L. – accepted – common comfrey
  Symphytum officinale var. officinale L. – not accepted
  Symphytum tuberosum L. – accepted – tuberous comfrey
  Syringa L. – accepted – lilac
  Syringa vulgaris L. – accepted – common lilac
  Syringa X persica L. – accepted – Persian lilac
  Tabernaemontana L. – accepted – milkwood
  Tabernaemontana citrifolia L. – accepted – bois lait, milkwood
  Tagetes L. – accepted – marigold
  Tagetes erecta L. – accepted – Aztec marigold, French marigold
  Tagetes minima L. – accepted – miniature marigold
  Tagetes minuta L. – accepted – muster John Henry, wild marigold, marigold, stinkweed
  Tagetes patula L. – not accepted – French marigold
  Tamarindus L. – accepted – tamarind
  Tamarindus indica L. – accepted – tamarind
  Tamarix L. – accepted – tamarisk
  Tamarix gallica L. – accepted – French tamarisk, tamarisk, saltcedar, tamarix
  Tanacetum L. – accepted – tansy
  Tanacetum balsamita L. – accepted – costmary
  Tanacetum vulgare L. – accepted – common tansy, tansy, golden-buttons, hierba lombriguera, garden tansy
  Targionia L. – accepted
  Targionia hypophylla L. – accepted
  Targionia hypophylla ssp. hypophylla L. – accepted
  Taxus L. – accepted – yew
  Taxus baccata L. – accepted – European yew, English yew
  Terminalia L. – accepted – tropical almond
  Terminalia catappa L. – accepted – India almond, false kamani, Indian almond, tropical almond
  Tetragonia L. – accepted – tetragonia, New Zealand spinach
  Tetragonotheca L. – accepted – nerveray
  Tetragonotheca helianthoides L. – accepted – pineland nerveray
  Tetragonothela L. – not accepted
  Tetragonothela helianthoides L. – not accepted
  Teucrium L. – accepted – germander
  Teucrium botrys L. – accepted – cutleaf germander
  Teucrium canadense L. – accepted – wood sage, hairy germander, American germander, Canada germander
  Teucrium canadense var. canadense L. – accepted – Canada germander, American germander
  Teucrium chamaedrys L. – accepted – wall germander
  Teucrium fruticans L. – accepted – shrubby germander
  Teucrium orientale L. – accepted – oriental germander, Oriental germander
  Teucrium scorodonia L. – accepted – woodland germander
  Thalia L. – not accepted
  Thalia L. – accepted – alligatorflag, alligator-flag
  Thalia geniculata L. – accepted – bent alligator-flag
  Thalictrum L. – accepted – meadowrue, meadow-rue
  Thalictrum alpinum L. – accepted – alpine meadowrue, alpine meadow-rue
  Thalictrum aquilefifolium L. – not accepted
  Thalictrum aquilegifolium L. – not accepted – columbine meadow-rue
  Thalictrum aquilegiifolium L. – accepted
  Thalictrum dioicum L. – accepted – early meadow-rue
  Thalictrum minus L. – accepted – small meadowrue
  Thalictrum minus ssp. minus L. – not accepted
  Thalictrum minus var. minus L. – not accepted
  Thea bohea L. – not accepted
  Thea sinensis L. – not accepted
  Thea viridis L. – not accepted
  Theobroma L. – accepted
  Theobroma cacao L. – accepted – cacao
  Theobroma cacao ssp. cacao L. – not accepted – cacao
  Theobroma cocao L. – not accepted
  Thesium L. – accepted
  Thesium linophyllon L. – accepted – flaxleaf
  Thlaspi L. – accepted – pennycress
  Thlaspi alliaceum L. – accepted – roadside pennycress
  Thlaspi arvense L. – accepted – Frenchweed, pennycress, stinkweed, fanweed, field pennycress
  Thlaspi bursa-pastoris L. – not accepted
  Thlaspi campestre L. – not accepted
  Thlaspi montanum L. – not accepted – alpine pennygrass, alpine pennycress
  Thlaspi montanum var. montanum L. – not accepted – alpine pennycress, alpine pennygrass
  Thlaspi perfoliatum L. – not accepted – claspleaf pennycress
  Thuja L. – accepted – arborvitae, cèdre, thuya, red cedar
  Thuja aphylla L. – not accepted
  Thuja occidentalis L. – accepted – arborvitae, cèdre-thuya occidental, eastern white cedar, northern white cedar, swamp cedar, thuier cèdre
  Thuja occidentslis L. – not accepted
  Thuja orientalis L. – not accepted – Chinese arborvitae, oriental arborvitae
  Thymus L. – accepted – thyme
  Thymus pulegioides L. – accepted – lemon thyme
  Thymus vulgaris L. – accepted – garden thyme
  Tiarella L. – accepted – foamflower
  Tiarella cordifolia L. – accepted – heartleaf foamflower
  Tiarella cordifolia var. cordifolia L. – not accepted – heartleaf foamflower
  Tiarella trifoliata L. – accepted – threeleaf foamflower
  Tiarella trifoliata var. trifoliata L. – accepted – threeleaf foamflower
  Tilia L. – accepted – basswood, lime tree, linden, tilleul
  Tilia americana L. – accepted – American basswood
  Tilia americana var. americana L. – not accepted – American basswood
  Tilia europaea L. – not accepted
  Tillaea aquatica L. – not accepted
  Tillaea muscosa L. – not accepted
  Tillandsia L. – accepted – air plant, airplant
  Tillandsia tenuifolia L. – accepted – narrowleaf airplant
  Tillandsia utriculata L. – accepted – Tillandsia base inflada, spreading airplant
  Tordylium L. – accepted
  Tordylium apulum L. – accepted – Mediterranean hartwort
  Torenia L. – accepted
  Torenia asiatica L. – accepted – wishbone flower
  Tournefortia L. – accepted – soldierbush
  Tournefortia hirsutissima L. – accepted – chiggery grapes
  Tournefortia sibirica L. – accepted – Siberian sea rosemary
  Tournefortia volubilis L. – not accepted – twining soldierbush
  Tradescantia L. – accepted – spider-lily, wandering-Jew, spiderwort
  Tradescantia virginiana L. – accepted – Virginia spiderwort
  Tragia L. – accepted – noseburn
  Tragia involucrata L. – accepted
  Tragia urens L. – accepted – wavyleaf noseburn
  Tragia volubilis L. – accepted – fireman
  Tragopogon L. – accepted – goatsbeard, salsify
  Tragopogon hybridus L. – accepted – pasture goatsbeard
  Tragopogon orientalis L. – not accepted
  Tragopogon porrifolius L. – accepted – salsify, purple salsify, common salsify, goatsbeard
  Tragopogon pratensis L. – accepted – Jack-go-to-bed-at-noon, meadow salsify
  Tragopogon pratensis ssp. pratensis L. – not accepted – Jack-go-to-bed-at-noon
  Trapa L. – accepted – water chestnut
  Trapa natans L. – accepted – water nut, water chestnut
  Trapa natans var. natans L. – not accepted – caltrop
  Trianthema L. – accepted – trianthema, horse purslane
  Trianthema portulacastrum L. – accepted – desert horse-purslane, horse purslane, desert horsepurslane
  Tribulus L. – accepted – puncture vine
  Tribulus cistoides L. – accepted – puncture vine, Jamaican feverplant
  Tribulus terrestris L. – accepted – bullhead, caltrop, Mexican sandbur, Texas sandbur, puncture vine, goathead
  Trichilia hirta L. – accepted – broomstick
  Trichomanes L. – accepted – bristle fern
  Trichomanes capillaceum L. – not accepted – treetrunk bristle fern
  Trichomanes crispum L. – accepted – crisped bristle fern
  Trichomanes hirsutum L. – not accepted
  Trichomanes membranaceum L. – not accepted – scale edge bristle fern
  Trichomanes polypodioides L. – accepted – jeweled bristle fern
  Trichomanes scandens L. – accepted – climbing bristle fern
  Trichosanthes L. – accepted
  Trichosanthes anguina L. – accepted – snakegourd
  Trichosanthes cucumerina L. – accepted – snakegourd
  Trichostema L. – accepted – bluecurls
  Trichostema brachiatum L. – accepted – fluxweed
  Trichostema dichotomum L. – accepted – forked bluecurls, blue curls
  Tridax L. – accepted – tridax
  Tridax procumbens L. – accepted – coatbuttons, cadillo chisaca, tridax, coat buttons
  Trientalis L. – accepted – starflower
  Trientalis europaea L. – accepted – arctic starflower
  Trientalis europaea ssp. europaea L. – not accepted – arctic starflower
  Trifolium L. – accepted – clover, trèfles
  Trifolium agrarium L. – not accepted
  Trifolium alexandrinum L. – accepted – Egyptian clover
  Trifolium alpestre L. – accepted – owl-head clover, purple-globe clover
  Trifolium alpinum L. – accepted – alpine clover
  Trifolium angustifolium L. – accepted – narrowleaf crimson clover
  Trifolium arvense L. – accepted – rabbitfoot clover, hare's foot clover, oldfield clover, stone clover, hairy clover, rabbit-foot clover
  Trifolium biflorum L. – not accepted
  Trifolium cherleri L. – accepted
  Trifolium clypeatum L. – accepted – shield clover
  Trifolium fragiferum L. – accepted – strawberry clover
  Trifolium fruticans L. – not accepted
  Trifolium globosum L. – accepted – round-head clover
  Trifolium glomeratum L. – accepted – clustered clover
  Trifolium hybridum L. – accepted – alsike clover
  Trifolium incarnatum L. – accepted – crimson clover
  Trifolium lappaceum L. – accepted – burdock clover
  Trifolium lupinaster L. – accepted – lupine clover
  Trifolium medium L. – accepted – zigzag clover
  Trifolium montanum L. – accepted – mountain clover
  Trifolium ornithopodioides L. – accepted – bird clover, bird's-foot-fenugreek
  Trifolium pratense L. – accepted – red clover
  Trifolium procumbens L. – not accepted
  Trifolium reflexum L. – accepted – buffalo clover
  Trifolium repens L. – accepted – white clover, Dutch clover, ladino clover, white Dutch clover
  Trifolium repens var. repens L. – not accepted – white clover
  Trifolium resupinatum L. – accepted – reversed clover, Persian clover
  Trifolium retusum L. – accepted – teasel clover
  Trifolium rubens L. – accepted
  Trifolium scabrum L. – accepted – rough clover
  Trifolium spadiceum L. – accepted – brown moor clover
  Trifolium spumosum L. – accepted – Mediterranean clover
  Trifolium squamosum L. – accepted – sea clover
  Trifolium squarrosum L. – accepted
  Trifolium stellatum L. – accepted – star clover, starry clover
  Trifolium striatum L. – accepted – knotted clover
  Trifolium strictum L. – accepted
  Trifolium subterraneum L. – accepted – subterranean clover
  Trifolium suffocatum L. – accepted – suffocated clover
  Trifolium tomentosum L. – accepted – woolly clover
  Trifolium uniflorum L. – accepted – oneflower clover
  Triglochin L. – accepted – troscart, arrowgrass, arrow-grass
  Triglochin maritima L. – accepted – troscart maritime, arrow-grass, seaside arrowgrass
  Triglochin maritimum L. – not accepted – seaside arrowgrass, seaside arrow-grass, shore arrowgrass, arrowgrass
  Triglochin palustre L. – not accepted – marsh arrowgrass, marsh arrow-grass
  Triglochin palustris L. – accepted – troscart des marais, marsh arrowgrass
  Trigonella L. – accepted – fenugreek
  Trigonella foenum-graecum L. – accepted – sicklefruit fenugreek
  Trigonella hamosa L. – accepted – branched fenugreek
  Trigonella monspeliaca L. – not accepted
  Trigonella polyceratia L. – not accepted
  Trigonella ramosa L. – not accepted
  Trigonella ruthenica L. – not accepted
  Trillium L. – accepted – trillium
  Trillium cernuum L. – accepted – whip-poor-will-flower, whip-poor-will flower
  Trillium erectum L. – accepted – red trillium
  Trillium sessile L. – accepted – toadshade
  Triosteum L. – accepted – horse-gentian
  Triosteum angustifolium L. – accepted – yellowfruit horsegentian, yellowfruit horse-gentian
  Triosteum angustifolium var. angustifolium L. – not accepted – yellowfruit horsegentian
  Triosteum perfoliatum L. – accepted – common horsegentian, feverwort
  Triplaris americana L. – accepted
  Tripsacum L. – accepted – gamagrass, gama grass
  Tripsacum hermaphrodita L. – not accepted
  Tripsacum hermaphroditum L. – not accepted
  Triticum L. – accepted – wheat
  Triticum aestivum L. – accepted – common wheat, wheat
  Triticum aestivum ssp. aestivum L. – accepted
  Triticum caninum L. – not accepted
  Triticum compositum L. – not accepted
  Triticum hybernum L. – not accepted
  Triticum junceum L. – not accepted
  Triticum monococcum L. – accepted – einkorn
  Triticum polonicum L. – accepted – Polish wheat
  Triticum repens L. – not accepted
  Triticum spelta L. – accepted – spelt
  Triticum turgidum L. – accepted – rivet wheat
  Triumfetta L. – accepted – burbark, burrbark
  Triumfetta bartramia L. – not accepted
  Triumfetta lappula L. – accepted – grandcousin
  Trollius L. – accepted – globeflower
  Trollius europaeus L. – accepted – European globeflower
  Tropaeolum L. – accepted – nasturtium
  Tropaeolum majas L. – not accepted
  Tropaeolum majus L. – accepted – nasturtium
  Tropaeolum minus L. – accepted – dwarf nasturtium
  Tulbaghia L. – accepted – wild garlic
  Tulipa L. – accepted – tulip
  Tulipa gesneriana L. – accepted – Didier's tulip
  Tulipa sylvestris L. – accepted – wild tulip
  Turnera L. – accepted
  Turnera cistoides L. – not accepted
  Turnera pumilea L. – accepted – yellow alder
  Turnera ulmifolia L. – accepted – ramgoat dashalong
  Turritis L. – accepted – tower mustard, towercress
  Turritis glabra L. – accepted – tower rockcress
  Tussilago L. – accepted – coltsfoot
  Tussilago farfara L. – accepted – coltsfoot, colts foot
  Tussilago nutans L. – not accepted
  Typha L. – accepted – cattail
  Typha angustifolia L. – accepted – narrowleaf cattail, narrow-leaf cat-tail
  Typha latifolia L. – accepted – cattail, common cattail, broadleaf cattail
  Ulex L. – accepted – gorse
  Ulex europaeus L. – accepted – common gorse, furze, gorse, whin
  Ulmus L. – accepted – elm
  Ulmus americana L. – accepted – American elm
  Ulmus campestris L. – not accepted
  Ulmus pumila L. – accepted – Siberian elm, Chinese elm
  Uniola L. – accepted – seaoats, uniola
  Uniola paniculata L. – accepted – seaoats
  Uniola spicata L. – not accepted
  Urena L. – accepted
  Urena lobata L. – accepted – Caesarweed, aramina, Caesar weed, chosuched e kui, dadangsi apaka, hibiscus burr, jute africain, common urena, bur-mallow, Congo jute
  Urena sinuata L. – accepted – burrmallow, bur mallow
  Urera lobata L. – not accepted
  Urtica L. – accepted – nettle
  Urtica aestuans L. – not accepted
  Urtica baccifera L. – not accepted
  Urtica canadensis L. – not accepted
  Urtica cylindrica L. – not accepted
  Urtica dioica L. – accepted – California nettle, slender nettle, tall nettle, stinging nettle
  Urtica dioica ssp. dioica L. – accepted – stinging nettle
  Urtica interrupta L. – not accepted
  Urtica nivea L. – not accepted
  Urtica parietaria L. – not accepted
  Urtica pumila L. – not accepted
  Urtica urens L. – accepted – burning nettle, dwarf nettle
  Utricularia L. – accepted – bladderwort
  Utricularia bifida L. – accepted – bladderwort
  Utricularia caerulea L. – accepted – bladderwort
  Utricularia foliosa L. – accepted – leafy bladderwort
  Utricularia gibba L. – accepted – humped bladderwort, conespur bladderpod
  Utricularia minor L. – accepted – lesser bladderwort
  Utricularia subulata L. – accepted – zigzag bladderwort
  Utricularia vulgaris L. – accepted
  Uvularia L. – accepted – bellwort
  Uvularia amplexifolia L. – not accepted
  Uvularia perfoliata L. – accepted – perfoliate bellwort
  Uvularia sessilifolia L. – accepted – sessile-leaf bellwort, sessileleaf bellwort
  Vaccinium L. – accepted – blueberries, huckleberry, blueberry
  Vaccinium corymbosum L. – accepted – highbush blueberry, New Jersey blueberry, Southern blueberry, smallflower blueberry
  Vaccinium frondosum L. – not accepted
  Vaccinium hispidulum L. – not accepted
  Vaccinium mucronatum L. – not accepted
  Vaccinium myrtillus L. – accepted – myrtle blueberry, myrtle whortleberry, whortleberry
  Vaccinium myrtillus var. myrtillus L. – not accepted – whortleberry
  Vaccinium oxycoccos L. – accepted – small cranberry
  Vaccinium oxycoccus L. – not accepted
  Vaccinium stamineum L. – accepted – deerberry
  Vaccinium uliginosum L. – accepted – bog blueberry
  Vaccinium vitis-idaea L. – accepted – lingonberry, northern mountain cranberry
  Vaccinium vitus-idaea L. – not accepted
  Valantia L. – accepted
  Valantia hispida L. – accepted
  Valantia hypocarpia L. – not accepted
  Valeriana L. – accepted – valerian
  Valeriana dioica L. – accepted – marsh valeriana, marsh valerian
  Valeriana dioica var. dioica L. – accepted
  Valeriana officinalis L. – accepted – garden heliotrope, garden valerian
  Valeriana scandens L. – accepted – Florida valerian
  Valeriana scandens var. scandens L. – not accepted – Florida valerian
  Vallisneria L. – accepted – eelgrass
  Vallisneria spiralis L. – accepted
  Vandellia diffusa L. – not accepted
  Varronia bullata L. – accepted
  Vateria L. – accepted
  Vateria indica L. – accepted – white dammar
  Velezia L. – accepted
  Velezia rigida L. – accepted
  Veratrum L. – accepted – false hellebore
  Veratrum album L. – accepted – white false hellebore
  Veratrum album ssp. album L. – not accepted – white false hellebore
  Veratrum album var. album L. – accepted – white false hellebore
  Veratrum luteum L. – not accepted
  Veratrum nigrum L. – accepted – false hellebore, black-hellebore
  Verbascum L. – accepted – mullein
  Verbascum blattaria L. – accepted – moth mullein, white moth mullein
  Verbascum lychnitis L. – accepted – white mullein
  Verbascum lychnitis ssp. lychnitis L. – accepted – white mullein
  Verbascum myconi L. – not accepted
  Verbascum nigrum L. – accepted – black mullein
  Verbascum phlomoides L. – accepted – orange mullein
  Verbascum phoeniceum L. – accepted – purple mullein
  Verbascum phoeniceum var. phoeniceum L. – accepted – purple mullein
  Verbascum phoenicium L. – not accepted
  Verbascum sinuatum L. – accepted – wavyleaf mullein
  Verbascum sinuatum var. sinuatum L. – accepted – wavyleaf mullein
  Verbascum thapsus L. – accepted – big taper, flannel plant, velvet dock, velvet plant, woolly mullein, flannel mullein, great mullein, mullein, common mullein
  Verbascum thapsus ssp. thapsus L. – accepted – common mullein
  Verbena L. – accepted – vervain
  Verbena bonariensis L. – accepted – pretty verbena, purpletop vervain
  Verbena bonariensis var. bonariensis L. – accepted – purpletop vervain
  Verbena carolina L. – accepted – Carolina vervain
  Verbena hastata L. – accepted – blue vervain, blue verbena, Simpler's-joy, swamp verbena
  Verbena hastata var. hastata L. – accepted – swamp verbena, Simpler's-joy
  Verbena officinalis L. – accepted – herb of the cross
  Verbena officinalis var. officinalis L. – accepted – herb of the cross
  Verbena supina L. – accepted – supine vervain
  Verbena urticifolia L. – accepted – white verbena, white vervain
  Verbena urticifolia var. urticifolia L. – accepted – white vervain
  Verbesina L. – accepted – crownbeard
  Verbesina alata L. – accepted – capitaneja
  Verbesina alba L. – not accepted
  Verbesina lavenia L. – not accepted
  Verbesina nodiflora L. – not accepted
  Verbesina prostrata L. – not accepted
  Verbesina virginica L. – accepted – white crownbeard, Virginia crownbeard, iceweed
  Verbesina virginica var. virginica L. – not accepted – white crownbeard, maritime groundcherry
  Veronica L. – accepted – speedwell
  Veronica agrestis L. – accepted – field speedwell, green field speedwell
  Veronica alpina L. – accepted – alpine speedwell
  Veronica alpina var. alpina L. – not accepted – alpine speedwell
  Veronica anagallis L. – not accepted – water speedwell
  Veronica anagallis L. – not accepted
  Veronica anagallis-aquatica L. – accepted – water speedwell, blue water speedwell
  Veronica arvensis L. – accepted – rock speedwell, wall speedwell, common speedwell, corn speedwell
  Veronica austriaca L. – accepted – broadleaf speedwell
  Veronica beccabunga L. – accepted – European speedwell
  Veronica biloba L. – accepted – bilobed speedwell, twolobed speedwell, twolobe speedwell
  Veronica chamaedrys L. – accepted – germander speedwell
  Veronica hederifolia L. – accepted – ivyleaf speedwell
  Veronica incana L. – accepted – spiked speedwell
  Veronica latifolia L. – not accepted
  Veronica longifolia L. – accepted – long-leaf speedwell, longleaf speedwell
  Veronica officinalis L. – accepted – common gypsyweed
  Veronica officinalis var. officinalis L. – accepted – common gypsyweed
  Veronica peregrina L. – accepted – purslane speedwell, neckweed
  Veronica peregrina ssp. peregrina L. – not accepted – neckweed
  Veronica prostrata L. – accepted – prostrate speedwell
  Veronica scutellata L. – accepted – grass-leaf speedwell, marsh speedwell, grassleaf speedwell, skullcap speedwell
  Veronica serpyllifolia L. – accepted – thyme-leaf speedwell, thymeleaf speedwell
  Veronica serpyllifolia ssp. serpyllifolia L. – not accepted – thymeleaf speedwell
  Veronica spicata L. – accepted – spiked speedwell
  Veronica spicata ssp. spicata L. – not accepted – spiked speedwell
  Veronica spuria L. – not accepted – bastard speedwell
  Veronica teucrium L. – accepted
  Veronica triphyllos L. – accepted – lobed speedwell, finger speedwell
  Veronica verna L. – accepted – spring speedwell
  Veronica virginica L. – not accepted
  Viburnum L. – accepted – viburnum
  Viburnum acerifolium L. – accepted – mapleleaf viburnum
  Viburnum acerifolium var. acerifolium L. – not accepted – mapleleaf arrowwood, mapleleaf viburnum
  Viburnum cassinoides L. – not accepted
  Viburnum dentatum L. – accepted – arrowwood, arrow-wood viburnum, southern arrowwood
  Viburnum dentatum var. dentatum L. – accepted – southern arrowwood
  Viburnum lantana L. – accepted – wayfaring tree, wayfaringtree
  Viburnum lentago L. – accepted – nannyberry, nanny-berry
  Viburnum nudum L. – accepted – possumhaw viburnum, possumhaw
  Viburnum nudum var. nudum L. – accepted – possumhaw
  Viburnum opulus L. – accepted – Guelder rose, viburnum, European cranberrybush
  Viburnum opulus var. opulus L. – accepted – European cranberrybush
  Viburnum opulus var. roseum L. – not accepted
  Viburnum prunifolium L. – accepted – blackhaw
  Viburnum tinus L. – accepted – laurustinus
  Vicia L. – accepted – vetch
  Vicia benghalensis L. – accepted – reddish tufted vetch, purple vetch
  Vicia biennis L. – accepted
  Vicia cassubica L. – accepted
  Vicia cracca L. – accepted – bird vetch, tufted vetch, cow vetch
  Vicia cracca ssp. cracca L. – not accepted – bird vetch
  Vicia dumetorum L. – accepted
  Vicia faba L. – accepted – horsebean
  Vicia hybrida L. – accepted – hairy yellow vetch
  Vicia lathyroides L. – accepted – spring vetch
  Vicia lutea L. – accepted – smooth yellow vetch
  Vicia narbonensis L. – accepted – purple broad vetch
  Vicia peregrina L. – accepted – wandering vetch
  Vicia pisiformis L. – accepted – pale-flower vetch, pea vetch
  Vicia sativa L. – accepted – garden vetch, common vetch, tare, narrowleaf vetch
  Vicia sativa ssp. sativa L. – not accepted – garden vetch
  Vicia sativa var. nigra L. – not accepted
  Vicia sativa var. sativa L. – accepted – garden vetch, common vetch, spring vetch, tare
  Vicia sepium L. – accepted – bush vetch, hedge vetch
  Vicia sepium var. sepium L. – accepted – bush vetch
  Vicia sylvatica L. – accepted – wood vetch
  Vinca L. – accepted – periwinkle
  Vinca major L. – accepted – greater periwinkle, periwinkle, bigleaf periwinkle
  Vinca minor L. – accepted – lesser periwinkle, myrtle, common periwinkle
  Vinca rosea L. – not accepted
  Viola L. – accepted – violettes, violet
  Viola biflora L. – accepted – arctic yellow violet
  Viola biflora ssp. biflora L. – not accepted – twoflower violet
  Viola biflora var. biflora L. – accepted – arctic yellow violet
  Viola canadensis L. – accepted – Canadian white violet, Canada violet
  Viola canadensis var. canadensis L. – accepted – Canadian white violet
  Viola canina L. – accepted – heath dog violet, dog violet
  Viola canina ssp. canina L. – accepted – dog violet, heath dog violet
  Viola lanceolata L. – accepted – lanceleaf violet, bog white violet
  Viola lanceolata ssp. lanceolata L. – not accepted – bog white violet
  Viola mirabilis L. – accepted – wonder violet
  Viola odorata L. – accepted – sweet violet
  Viola palmata L. – accepted – trilobed violet, three-lobe violet, wood violet, early blue violet
  Viola palmata var. palmata L. – not accepted – violet
  Viola palustris L. – accepted – marsh violet
  Viola palustris var. palustris L. – not accepted – marsh violet
  Viola pedata L. – accepted – birdfoot violet
  Viola pedata var. pedata L. – accepted – birdfoot violet
  Viola primulifolia L. – accepted
  Viola primulifolia var. primulifolia L. – accepted
  Viola tricolor L. – accepted – pansy violet, Johnny-jump-up
  Viscum L. – accepted – mistletoe
  Viscum album L. – accepted – European mistletoe
  Vitex L. – accepted – chastetree
  Vitex agnus-castus L. – accepted – chaste tree, lilac chastetree
  Vitex agnus-castus var. agnus-castus L. – accepted – lilac chastetree
  Vitex negundo L. – accepted – negundo chastetree, Chinese chastetree
  Vitex negundo var. negundo L. – accepted – Chinese chastetree, negundo chastetree
  Vitex trifolia L. – accepted – simpleleaf chastetree
  Vitex trifolia var. trifolia L. – accepted – simpleleaf chastetree
  Vitis L. – accepted – grape
  Vitis labrusca L. – accepted – fox grape
  Vitis vinifera L. – accepted – wine grape
  Vitis vulpina L. – accepted – wild grape, fox grape, frost grape
  Volkameria L. – accepted
  Volkameria aculeata L. – accepted – haggarbush
  Volkameria inermis L. – accepted – embrert
  Waltheria L. – accepted
  Waltheria americana L. – not accepted
  Waltheria indica L. – accepted – uhaloa, basora-prieta, sleepy morning, hierba del soldado, malva del monte, malva blanca
  Weinmannia L. – accepted
  Weinmannia pinnata L. – accepted – bastard briziletto
  Winterana L. – not accepted
  Winterana canella L. – not accepted
  Xanthium L. – accepted – cocklebur
  Xanthium orientale L. – not accepted
  Xanthium spinosum L. – accepted – spiny cocklebur, Bathurst burr, cocklebur, spiny cockleburr
  Xanthium strumarium L. – accepted – rough cocklebur, Canada cocklebur, cocklebur, common cocklebur, rough cockleburr, cockleburr
  Xanthium strumarium var. strumarium L. – not accepted – common cocklebur, rough cocklebur, cocklebur, rough cockleburr
  Ximenia L. – accepted
  Ximenia americana L. – accepted – tallow wood, tallowwood
  Ximenia inermis L. – not accepted
  Xylophylia L. – not accepted
  Xylophylla L. – not accepted
  Xylopia L. – accepted
  Xyris L. – accepted – yellow-eyed-grass, yelloweyed grass
  Xyris indica L. – accepted
  Yucca L. – accepted – yucca species, yucca
  Yucca aliofolia L. – not accepted
  Yucca aloifolia L. – accepted – aloe yucca, Izote Kukil
  Yucca filamentosa L. – accepted – Adam's needle
  Yucca gloriosa L. – accepted – moundlily yucca
  Yucca gloriosa var. gloriosa L. – accepted – moundlily yucca
  Zamia L. – accepted
  Zamia pumila L. – accepted – coontie
  Zamia pumila ssp. pumila L. – not accepted – coontie
  Zannichellia L. – accepted – pondweed, horned pondweed
  Zannichellia palustris L. – accepted – horned pondweed, horned poolmat, horned-pondweed
  Zanthoxylum L. – accepted – pricklyash
  Zanthoxylum clava-herculis L. – accepted – Hercules-club, Hercules-club pricklyash, Hercules' club
  Zea L. – accepted – corn
  Zea mays L. – accepted – corn
  Zea mays ssp. mays L. – accepted – corn
  Zea mays var. mays L. – accepted
  Zinnia L. – accepted – zinnia
  Zinnia multiflora L. – not accepted
  Zinnia pauciflora L. – not accepted
  Zizania L. – accepted – wildrice
  Zizania aquatica L. – accepted – annual wildrice
  Zizania aquatica ssp. aquatica L. – not accepted
  Zizania aquatica var. aquatica L. – accepted – Indian wild rice, zizanie à fleurs blanches variété à fleurs blanches, annual wildrice
  Zizania palustris L. – accepted – northern wildrice
  Zizania palustris ssp. palustris L. – not accepted
  Zizania palustris var. palustris L. – accepted – northern wildrice
  Zostera L. – accepted – eelgrass
  Zostera marina L. – accepted – eelgrass, seawrack
  Zostera marina var. marina L. – not accepted – seawrack
  Zygophyllum L. – accepted – beancaper
  Zygophyllum fabago L. – accepted – Syrian beancaper
   

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