List of flora of Indiana

This list includes plants native and introduced to the state of Indiana, designated (N) and (I), respectively. Varieties and subspecies link to their parent species.

A

 * Abies balsamea var. balsamea (I)
 * Abutilon theophrasti (I)
 * Acalypha deamii (N)
 * Acalypha gracilens (N)
 * Acalypha ostryifolia (N)
 * Acalypha rhomboidea (N)
 * Acalypha virginica (N)
 * Acer campestre (I) -- field maple
 * Acer × freemanii (N) -- Freeman maple
 * Acer ginnala (I) --  Amur maple
 * Acer negundo var. negundo (N) --  boxelder maple
 * Acer negundo var. violaceum (N) --
 * Acer nigrum (N) --  black maple
 * Acer palmatum (I) --
 * Acer pensylvanicum (N) --  striped maple, moosewood
 * Acer platanoides (I) --
 * Acer rubrum var. rubrum (N) --  red maple
 * Acer rubrum var. trilobum (N) --
 * Acer saccharinum (N) --  silver mapl
 * Acer saccharum var. saccharum (N) --  sugar maple
 * Acer spicatum (N) --  mountain maple, dwarf maple
 * Acer tataricum (I) --
 * Achillea millefolium var. occidentalis (N)
 * Achillea millefolium var. millefolium (I)
 * Achillea ptarmica (I)
 * Achyranthes japonica var. hachijoensis (I)
 * Acinos arvensis, synonym of Clinopodium acinos (I)
 * Aconitum noveboracense (N)
 * Aconitum uncinatum ssp. uncinatum (N)
 * Acorus americanus (N)
 * Acorus calamus (I)
 * Acroptilon repens (I)
 * Actaea pachypoda (N)
 * Actaea racemosa var. racemosa (N)
 * Actaea rubra ssp. rubra (N)
 * Actinidia arguta (I)
 * Adiantum capillus-veneris (N)
 * Adiantum pedatum (N)
 * Adlumia fungosa (N)
 * Aegilops cylindrica (I)
 * Aegopodium podagraria (I)
 * Aesculus flava (N)
 * Aesculus glabra var. glabra (N)
 * Aesculus hippocastanum (I)
 * Aesculus × marylandica (N)
 * Aethusa cynapium (I)
 * Agalinis auriculata (N)
 * Agalinis gattingeri (N)
 * Agalinis paupercula var. borealis (N)
 * Agalinis paupercula var. paupercula (N)
 * Agalinis purpurea (N)
 * Agalinis skinneriana (N)
 * Agalinis tenuifolia var. macrophylla (N)
 * Agalinis tenuifolia var. parviflora (N)
 * Agalinis tenuifolia var. tenuifolia (N)
 * Agastache nepetoides (N)
 * Agastache scrophulariifolia (N)
 * Ageratina altissima var. altissima (N)
 * Ageratina aromatica var. aromatica (N)
 * Agrimonia eupatoria (I)
 * Agrimonia gryposepala (N) --  common agrimony
 * Agrimonia microcarpa (N)
 * Agrimonia parviflora (N)
 * Agrimonia pubescens (N)
 * Agrimonia rostellata (N)
 * Agrimonia striata (N)
 * Agropyron desertorum (I)
 * Agrostemma githago (I)
 * Agrostis avenacea (I)
 * Agrostis capillaris (I)
 * Agrostis elliottiana (N) --  Elliott's bent grass
 * Agrostis gigantea (I)
 * Agrostis hyemalis (N)
 * Agrostis perennans (N)
 * Agrostis scabra (N)
 * Agrostis stolonifera (I)
 * Ailanthus altissima (I)
 * Aira caryophyllea var. caryophyllea (I)
 * Ajuga genevensis (I)
 * Ajuga reptans (I)
 * Akebia quinata (I)
 * Albizia julibrissin (I)
 * Alcea rosea (I)
 * Aletris farinosa (N)
 * Alisma subcordatum (N)
 * Alisma triviale (N)
 * Alliaria petiolata (I)
 * Allium ampeloprasum (I)
 * Allium burdickii (N)
 * Allium canadense var. canadense (N)
 * Allium cepa (I)
 * Allium cernuum var. cernuum (N)
 * Allium porrum (I)
 * Allium sativum (I)
 * Allium schoenoprasum (I)
 * Allium schoenoprasum var. sibiricum (N)
 * Allium tricoccum (N)
 * Allium vineale ssp. vineale (I)
 * Alnus × fallacina (N)
 * Alnus glutinosa (I)
 * Alnus incana ssp. rugosa (N)
 * Alnus serrulata (N)
 * Alopecurus aequalis var. aequalis (N)
 * Alopecurus carolinianus (N)
 * Alopecurus geniculatus var. geniculatus (I)
 * Alopecurus myosuroides (I)
 * Alopecurus myosuroides (N)
 * Alopecurus pratensis (I)
 * Althaea officinalis (I)
 * Alyssum alyssoides (I)
 * Amaranthus albus (I) --  common tumbleweed,
 * Amaranthus blitoides (I) --
 * Amaranthus blitum var. emarginatus (I) --
 * Amaranthus cruentus (I) --
 * Amaranthus deflexus (I) --
 * Amaranthus hybridus (N) -- green amaranth
 * Amaranthus palmeri (N) --  Palmer's pigweed
 * Amaranthus powellii ssp. powellii (N) --
 * Amaranthus retroflexus (N) --
 * Amaranthus spinosus (N) --
 * Amaranthus tuberculatus (N) --
 * Ambrosia artemisiifolia var. elatior (N)
 * Ambrosia artemisiifolia var. elatior (I)
 * Ambrosia bidentata (N)
 * Ambrosia × helenae (N)
 * Ambrosia trifida var. trifida (N)
 * Amelanchier arborea var. arborea (N)
 * Amelanchier interior (N)
 * Amelanchier laevis (N)
 * Amelanchier sanguinea var. sanguinea (N)
 * Amelanchier stolonifera (N)
 * Ammannia coccinea (N)
 * Ammannia robusta (N)
 * Ammophila breviligulata (N)
 * Amorpha fruticosa (N)
 * Ampelopsis aconitifolia (I)
 * Ampelopsis arborea (N)
 * Ampelopsis glandulosa var. brevipedunculata (I)
 * Ampelopsis cordata (N)
 * Amphiachyris dracunculoides (N)
 * Amphicarpaea bracteata var. bracteata (N)
 * Amphicarpaea bracteata var. comosa (N)
 * Amsinckia lycopsoides (N)
 * Amsonia tabernaemontana var. salicifolia (N)
 * Anagallis arvensis ssp. foemina (N)
 * Anagallis arvensis ssp. arvensis (I)
 * Anagallis arvensis ssp. foemina (I)
 * Anagallis minima (N)
 * Anaphalis margaritacea (N)
 * Anchusa arvensis (I)
 * Anchusa azurea (I)
 * Anchusa officinalis (I)
 * Andromeda polifolia var. glaucophylla (N)
 * Andropogon gerardi (N)
 * Andropogon glomeratus var. glomeratus (N)
 * Andropogon gyrans var. gyrans (N)
 * Andropogon virginicus var. virginicus (N)
 * Androsace occidentalis (N)
 * Anemone blanda (I)
 * Anemone canadensis (N)
 * Anemone cylindrica (N)
 * Anemone quinquefolia var. bifolia (N)
 * Anemone quinquefolia var. quinquefolia (N)
 * Anemone virginiana var. virginiana (N)
 * Anethum graveolens (I)
 * Angelica atropurpurea (N)
 * Angelica venenosa (N)
 * Anoda cristata (N)
 * Antennaria howellii ssp. canadensis (N)
 * Antennaria howellii ssp. neodioica (N)
 * Antennaria howellii ssp. petaloidea (N)
 * Antennaria neglecta (N)
 * Antennaria parlinii ssp. fallax (N)
 * Antennaria parlinii ssp. parlinii (N)
 * Antennaria plantaginifolia (N)
 * Antennaria solitaria (N)
 * Antennaria virginica (N)
 * Anthemis arvensis (I)
 * Anthemis cotula (I)
 * Anthemis tinctoria (I)
 * Anthoxanthum aristatum (I)
 * Anthoxanthum odoratum ssp. odoratum (I)
 * Anthriscus caucalis (I)
 * Anthriscus sylvestris (I)
 * Anthyllis vulneraria (I)
 * Antirrhinum majus (I)
 * Apera interrupta (I)
 * Apera spica-venti (I)
 * Apios americana (N)
 * Apium graveolens var. dulce (N)
 * Apium graveolens var. dulce (I)
 * Aplectrum hyemale (N)
 * Apocynum androsaemifolium (N)
 * Apocynum cannabinum (N)
 * Apocynum × floribundum (N)
 * Aquilegia canadensis (N)
 * Aquilegia vulgaris (I)
 * Arabidopsis thaliana (I)
 * Arabis canadensis (N)
 * Arabis × divaricarpa (N)
 * Arabis drummondii (N)
 * Arabis glabra (N)
 * Arabis hirsuta var. pycnocarpa (N)
 * Arabis laevigata var. laevigata (N)
 * Arabis lyrata (N)
 * Arabis missouriensis (N)
 * Arabis patens (N)
 * Arabis shortii (N)
 * Aralia elata (I)
 * Aralia hispida (N)
 * Aralia nudicaulis (N)
 * Aralia racemosa ssp. racemosa (N)
 * Aralia spinosa (N)
 * Arctium lappa (I)
 * Arctium minus (I)
 * Arctostaphylos uva-ursi (N)
 * Arenaria serpyllifolia (I)
 * Arethusa bulbosa (N)
 * Argemone albiflora ssp. albiflora (N)
 * Argemone mexicana (N)
 * Argentina anserina (N)
 * Arisaema dracontium (N)
 * Arisaema triphyllum ssp. pusillum (N)
 * Arisaema triphyllum ssp. stewardsonii (N)
 * Arisaema triphyllum ssp. triphyllum (N)
 * Aristida dichotoma var. dichotoma (N)
 * Aristida longespica var. geniculata (N)
 * Aristida longespica var. longespica (N)
 * Aristida oligantha (N)
 * Aristida purpurascens var. purpurascens (N)
 * Aristida ramosissima (N)
 * Aristolochia clematitis (I)
 * Aristolochia serpentaria (N)
 * Aristolochia tomentosa (N)
 * Armoracia rusticana (I)
 * Arnoglossum atriplicifolium (N)
 * Arnoglossum plantagineum (N)
 * Arnoglossum reniforme (N)
 * Arnoseris minima (I)
 * Arrhenatherum elatius var. elatius (I)
 * Artemisia absinthium (I)
 * Artemisia annua (I)
 * Artemisia biennis (N)
 * Artemisia biennis var. biennis (I)
 * Artemisia campestris ssp. borealis var. borealis (N)
 * Artemisia campestris ssp. caudata (N)
 * Artemisia gmelinii (I)
 * Artemisia ludoviciana ssp. albula (N)
 * Artemisia ludoviciana ssp. ludoviciana (N)
 * Artemisia pontica (I)
 * Artemisia stelleriana (I)
 * Artemisia stelleriana (N)
 * Artemisia vulgaris (N)
 * Artemisia vulgaris var. vulgaris (I)
 * Arthraxon hispidus (I)
 * Aruncus dioicus (I)
 * Aruncus dioicus var. dioicus (N)
 * Arundinaria gigantea ssp. gigantea (N)
 * Asarum canadense (N)
 * Asclepias amplexicaulis (N) -- sand milkweed
 * Asclepias exaltata (N) -- poke milkweed
 * Asclepias hirtella (N) -- tall green milkweed
 * Asclepias incarnata ssp. incarnata (N) -- swamp milkweed
 * Asclepias purpurascens (N) -- purple milkweed
 * Asclepias quadrifolia (N) -- whorled milkweed
 * Asclepias sullivantii (N) -- prairie milkweed
 * Asclepias syriaca (N) -- common milkweed
 * Asclepias tuberosa ssp. interior (N) -- butterfly weed
 * Asclepias tuberosa ssp. tuberosa (N) -- butterfly weed
 * Asclepias variegata (N) -- white milkweed
 * Asclepias verticillata (N) -- eastern whorled milkweed
 * Asclepias viridiflora (N) -- green-flower milkweed
 * Asclepias viridis (N) -- green or spider milkweed
 * Asimina triloba (N)
 * Asparagus officinalis (I)
 * Asperugo procumbens (I)
 * Asplenium bradleyi (N) --  Bradley's spleenwort or cliff spleenwort
 * Asplenium × clermontiae (N)
 * Asplenium × ebenoides (N)
 * Asplenium × gravesii (N)
 * Asplenium × inexpectatum (N)
 * Asplenium × kentuckiense (N)
 * Asplenium montanum (N)
 * Asplenium pinnatifidum (N)
 * Asplenium platyneuron var. platyneuron (N)
 * Asplenium resiliens (N)
 * Asplenium rhizophyllum (N)
 * Asplenium ruta-muraria var. cryptolepis (N)
 * Asplenium ruta-muraria var. lanceolum (N)
 * Asplenium trichomanes ssp. quadrivalens (N)
 * Asplenium trichomanes ssp. trichomanes (N)
 * Asplenium × trudellii (N)
 * Aster tataricus (I)
 * Astragalus canadensis var. canadensis (N)
 * Astragalus neglectus (N)
 * Athyrium filix-femina ssp. angustum (N)
 * Athyrium filix-femina ssp. asplenioides (N)
 * Atriplex hortensis (I)
 * Atriplex patula (I)
 * Atriplex prostrata (N)
 * Atriplex rosea (I)
 * Aureolaria flava var. flava (N)
 * Aureolaria flava var. macrantha (N)
 * Aureolaria levigata (N)
 * Aureolaria pedicularia var. ambigens (N)
 * Aureolaria pedicularia var. pedicularia (N)
 * Aureolaria virginica (N)
 * Aurinia saxatilis (I)
 * Avena fatua (I)
 * Avena sativa (I)
 * Azolla caroliniana (N)

B

 * Ballota nigra var. alba (I)
 * Baptisia alba var. macrophylla (N)
 * Baptisia australis var. australis (N)
 * Baptisia tinctoria (N)
 * Barbarea verna (I)
 * Barbarea vulgaris (I)
 * Bartonia virginica (N)
 * Bassia hirsuta (I)
 * Bassia scoparia (I)
 * Beckmannia syzigachne (N)
 * Belamcanda chinensis (I)
 * Bellis perennis (I)
 * Berberis × ottawensis (N)
 * Berberis thunbergii (I)
 * Berberis vulgaris (I)
 * Berteroa incana (I)
 * Besseya bullii (N)
 * Betula alleghaniensis var. alleghaniensis (N) --  yellow birch
 * Betula alleghaniensis var. macrolepis (N) --  yellow birch
 * Betula lenta (N) --  Black birch, cherry birch
 * Betula nigra (N) --  black birch, river birch or water birch
 * Betula papyrifera var. papyrifera (N) --  paper birch, white birch and canoe birch
 * Betula pendula (I) --
 * Betula populifolia (N) --  gray or grey birch
 * Betula pubescens (N) -- downy birch
 * Betula pubescens ssp. pubescens (I) --
 * Betula pumila var. pumila (N) --
 * Betula × purpusii (N) --
 * Bidens aristosa (N) --  bearded beggarticks
 * Bidens beckii (N)
 * Bidens bipinnata (N)
 * Bidens cernua (N)
 * Bidens connata (N)
 * Bidens coronata (N)
 * Bidens discoidea (N)
 * Bidens frondosa (N)
 * Bidens laevis (N)
 * Bidens tripartita (N)
 * Bidens vulgata (N)
 * Bignonia capreolata (N)
 * Blephilia ciliata (N)
 * Blephilia hirsuta var. hirsuta (N)
 * Boehmeria cylindrica (N)
 * Boltonia asteroides var. recognita (N)
 * Borago officinalis (I)
 * Botrychium biternatum (N)
 * Botrychium dissectum (N)
 * Botrychium lanceolatum var. angustisegmentum (N)
 * Botrychium matricariifolium (N)
 * Botrychium multifidum (N)
 * Botrychium oneidense (N)
 * Botrychium simplex (N)
 * Botrychium virginianum (N)
 * Bouteloua curtipendula var. curtipendula (N)
 * Bouteloua gracilis (N)
 * Bouteloua hirsuta var. hirsuta (N)
 * Brachyelytrum erectum (N)
 * Brasenia schreberi (N)
 * Brassica juncea (I) --   brown mustard, Chinese mustard, Indian mustard
 * Brassica napus (I)
 * Brassica nigra (I)
 * Brassica oleracea (I)
 * Brassica rapa var. amplexicaulis (I)
 * Brassica rapa var. rapa (I)
 * Brickellia eupatorioides var. corymbulosa (N)
 * Brickellia eupatorioides var. eupatorioides (N)
 * Bromus arvensis (I)
 * Bromus briziformis (I)
 * Bromus catharticus (I)
 * Bromus ciliatus var. ciliatus (N)
 * Bromus erectus (I)
 * Bromus hordeaceus ssp. hordeaceus (I)
 * Bromus inermis (N)
 * Bromus inermis ssp. inermis var. inermis (I)
 * Bromus kalmii (N)
 * Bromus latiglumis (N)
 * Bromus nottowayanus (N)
 * Bromus pubescens (N)
 * Bromus racemosus (I)
 * Bromus secalinus var. secalinus (I)
 * Bromus sterilis (I)
 * Bromus tectorum (I)
 * Broussonetia papyrifera (I)
 * Browallia americana (I)
 * Brunnera macrophylla (I)
 * Buchnera americana (N)
 * Buddleja davidii (I)
 * Buglossoides arvensis (I)
 * Bulbostylis capillaris ssp. capillaris (N)
 * Bunias orientalis (I)
 * Bupleurum lancifolium (I)
 * Bupleurum rotundifolium (I)
 * Butomus umbellatus (I)
 * Buxus sempervirens (I)

C

 * Cabomba caroliniana var. caroliniana (N)
 * Cakile edentula ssp. edentula var. lacustris (N)
 * Cakile edentula ssp. edentula (N)
 * Calamagrostis canadensis var. canadensis (N)
 * Calamagrostis canadensis var. macouniana (N)
 * Calamagrostis coarctata (N)
 * Calamagrostis porteri ssp. insperata (N)
 * Calamagrostis stricta ssp. inexpansa (N)
 * Calamovilfa longifolia var. magna (N)
 * Calendula officinalis (I)
 * Calla palustris (N)
 * Callitriche heterophylla ssp. heterophylla (N)
 * Callitriche palustris (N)
 * Callitriche terrestris (N)
 * Calluna vulgaris (I)
 * Calopogon tuberosus var. tuberosus (N)
 * Caltha palustris var. palustris (N)
 * Calycanthus floridus var. glaucus (N)
 * Calystegia hederacea (I)
 * Calystegia sepium ssp. americana (N)
 * Calystegia sepium ssp. angulata (N)
 * Calystegia sepium ssp. sepium (I)
 * Calystegia silvatica (I)
 * Calystegia silvatica ssp. fraterniflora (N)
 * Calystegia spithamaea ssp. spithamaea (N)
 * Camassia scilloides (N)
 * Camelina microcarpa (I)
 * Camelina sativa ssp. sativa (I)
 * Campanula aparinoides (N)
 * Campanula rapunculoides (I)
 * Campanula rotundifolia (N)
 * Campanula trachelium (I)
 * Campanulastrum americanum (N)
 * Campsis radicans (N)
 * Cannabis sativa ssp. sativa var. sativa (I)
 * Capsella bursa-pastoris (I)
 * Cardamine angustata (N)
 * Cardamine bulbifera (I)
 * Cardamine bulbosa (N)
 * Cardamine concatenata (N)
 * Cardamine diphylla (N)
 * Cardamine dissecta (N)
 * Cardamine douglassii (N)
 * Cardamine flexuosa (I)
 * Cardamine hirsuta (I)
 * Cardamine impatiens (I)
 * Cardamine maxima (N)
 * Cardamine parviflora var. arenicola (N)
 * Cardamine pensylvanica (N)
 * Cardamine pratensis var. pratensis (N)
 * Cardamine rotundifolia (N)
 * Cardaria draba (I)
 * Cardiospermum halicacabum (I)
 * Carduus acanthoides (I)
 * Carduus crispus (I)
 * Carduus nutans (I)
 * Carex aggregata (N) --
 * Carex alata (N) --  broad-winged sedge
 * Carex albicans var. albicans (N) --  whitetinge sedge
 * Carex albicans var. emmonsii (N) --  whitetinge sedge
 * Carex albolutescens (N) --  greenish-white sedge
 * Carex albursina (N) --  White Bear sedge
 * Carex alopecoidea (N) --  foxtail sedge
 * Carex amphibola (N) --  gray sedge
 * Carex annectens (N) --
 * Carex appalachica (N) --
 * Carex aquatilis var. aquatilis (N) --
 * Carex arctata (N) --
 * Carex argyrantha (N) --
 * Carex atherodes (N) --
 * Carex atlantica ssp. atlantica (N) --
 * Carex atlantica ssp. capillacea (N) --
 * Carex aurea (N) --
 * Carex bebbii (N) --
 * Carex bicknellii (N) --
 * Carex blanda (N) --
 * Carex brevior (N) --
 * Carex bromoides ssp. bromoides (N) --
 * Carex brunnescens ssp. sphaerostachya (N) --
 * Carex bushii (N) --
 * Carex buxbaumii (N) --
 * Carex canescens ssp. canescens (N) --
 * Carex canescens ssp. disjuncta (N) --
 * Carex careyana (N) --
 * Carex caroliniana (N) --
 * Carex cephaloidea (N) --
 * Carex cephalophora (N) --
 * Carex communis var. communis (N) --
 * Carex comosa (N) --
 * Carex conjuncta (N) --
 * Carex conoidea (N) --
 * Carex crawei (N) --
 * Carex crinita var. brevicrinis (N) --
 * Carex crinita var. crinita (N) --
 * Carex cristatella (N) --
 * Carex crus-corvi (N) --
 * Carex cryptolepis (N) --
 * Carex cumberlandensis (N) --
 * Carex davisii (N) --
 * Carex debilis var. debilis (N) --
 * Carex debilis var. rudgei (N)
 * Carex decomposita (N)
 * Carex deweyana var. deweyana (N)
 * Carex diandra (N)
 * Carex digitalis var. digitalis (N)
 * Carex disperma (N)
 * Carex eburnea (N)
 * Carex echinata ssp. echinata (N)
 * Carex emoryi (N)
 * Carex festucacea (N)
 * Carex flava (N)
 * Carex folliculata (N)
 * Carex formosa (N)
 * Carex frankii (N)
 * Carex garberi (N)
 * Carex glaucodea (N)
 * Carex gracilescens (N)
 * Carex gracillima (N)
 * Carex granularis (N)
 * Carex grayi (N)
 * Carex grisea (N) --
 * Carex gynandra (N) --
 * Carex haydenii (N) --
 * Carex hirsutella (N) --
 * Carex hirtifolia (N) --
 * Carex hitchcockiana (N) --
 * Carex hyalinolepis (N) --
 * Carex hystericina (N) --
 * Carex interior (N) --
 * Carex intumescens (N) --
 * Carex jamesii (N) --
 * Carex juniperorum (N) --
 * Carex lacustris (N) --
 * Carex laevivaginata (N) --
 * Carex lasiocarpa var. americana (N) --
 * Carex laxiculmis var. copulata (N) --
 * Carex laxiculmis var. laxiculmis (N) --
 * Carex laxiflora var. laxiflora (N) --
 * Carex leavenworthii (N) --
 * Carex leptalea ssp. leptalea (N) --
 * Carex leptonervia (N) --
 * Carex limosa (N) --
 * Carex longii (N) --
 * Carex louisianica (N) --
 * Carex lucorum var. lucorum (N) --
 * Carex lupuliformis (N) --
 * Carex lupulina (N) --
 * Carex lurida (N) --
 * Carex magellanica ssp. irrigua (N) --
 * Carex meadii (N) --
 * Carex merritt-fernaldii (N) --
 * Carex mesochorea (N) --
 * Carex molesta (N)
 * Carex muehlenbergii var. enervis (N)
 * Carex muehlenbergii var. muehlenbergii (N)
 * Carex muskingumensis (N)
 * Carex nigromarginata (N)
 * Carex normalis (N)
 * Carex oligocarpa (N)
 * Carex oligosperma var. oligosperma (N)
 * Carex pallescens (N)
 * Carex peckii (N)
 * Carex pedunculata (N)
 * Carex pellita (N)
 * Carex pensylvanica (N)
 * Carex planispicata (N)
 * Carex plantaginea (N)
 * Carex platyphylla (N)
 * Carex praegracilis (N)
 * Carex prairea (N)
 * Carex prasina (N)
 * Carex projecta (N)
 * Carex pseudocyperus (N)
 * Carex purpurifera (N)
 * Carex radiata (N)
 * Carex retroflexa (N)
 * Carex retrorsa (N)
 * Carex richardsonii (N)
 * Carex rosea (N)
 * Carex sartwellii var. sartwellii (N)
 * Carex scabrata (N)
 * Carex scoparia var. scoparia (N)
 * Carex seorsa (N)
 * Carex shortiana (N)
 * Carex siccata (N)
 * Carex sparganioides (N)
 * Carex spicata (I)
 * Carex sprengelii (N)
 * Carex squarrosa (N)
 * Carex sterilis (N)
 * Carex stipata var. maxima (N)
 * Carex stipata var. stipata (N)
 * Carex straminea (N)
 * Carex striatula (N)
 * Carex stricta (N)
 * Carex styloflexa (N)
 * Carex suberecta (N)
 * Carex × subimpressa (N)
 * Carex × sullivantii (N)
 * Carex swanii (N)
 * Carex tenera (N)
 * Carex tenuiflora (N)
 * Carex tetanica (N)
 * Carex texensis (N)
 * Carex timida (N)
 * Carex tonsa var. rugosperma (N)
 * Carex torta (N)
 * Carex tribuloides var. tribuloides (N)
 * Carex trichocarpa (N)
 * Carex trisperma var. trisperma (N)
 * Carex tuckermanii (N)
 * Carex typhina (N)
 * Carex umbellata (N)
 * Carex utriculata (N)
 * Carex vesicaria var. monile (N)
 * Carex virescens (N)
 * Carex viridula ssp. viridula (N)
 * Carex vulpinoidea var. vulpinoidea (N)
 * Carex willdenowii (N)
 * Carex woodii (N)
 * Carpinus caroliniana ssp. virginiana (N)
 * Carthamus tinctorius (I)
 * Carum carvi (I)
 * Carya alba (N)
 * Carya × brownii (N)
 * Carya cordiformis (N)
 * Carya glabra (N)
 * Carya illinoinensis (N)
 * Carya laciniosa (N)
 * Carya ovalis (N)
 * Carya ovata (N)
 * Castanea dentata (N)
 * Castanea pumila var. pumila (N)
 * Castilleja coccinea (N)
 * Catalpa bignonioides (N)
 * Catalpa ovata (I)
 * Catalpa speciosa (N)
 * Caulophyllum giganteum (N)
 * Caulophyllum thalictroides (N)
 * Ceanothus americanus (N)
 * Ceanothus herbaceus (N)
 * Celastrus orbiculatus (I)
 * Celastrus scandens (N)
 * Celosia argentea (I)
 * Celtis occidentalis (N)
 * Celtis tenuifolia (N)
 * Cenchrus longispinus (N)
 * Centaurea cyanus (I)
 * Centaurea diffusa (I)
 * Centaurea jacea (I)
 * Centaurea nigra (I)
 * Centaurea nigrescens (I)
 * Centaurea phrygia (I)
 * Centaurea scabiosa (I)
 * Centaurea solstitialis (I)
 * Centaurea stoebe ssp. micranthos (I)
 * Centaurea transalpina (N)
 * Centaurium erythraea (I)
 * Centaurium pulchellum (I)
 * Centella erecta (N)
 * Cephalanthus occidentalis (N)
 * Cerastium arvense (I)
 * Cerastium arvense ssp. strictum (N)
 * Cerastium arvense ssp. velutinum var. velutinum (N)
 * Cerastium arvense ssp. velutinum (N)
 * Cerastium brachypetalum (I)
 * Cerastium dubium (I)
 * Cerastium fontanum ssp. vulgare (I)
 * Cerastium glomeratum (I)
 * Cerastium nutans var. nutans (N)
 * Cerastium pumilum (I)
 * Cerastium semidecandrum (I)
 * Cerastium tomentosum (I)
 * Ceratocephala testiculata (I)
 * Ceratophyllum demersum (N)
 * Ceratophyllum echinatum (N)
 * Cercidiphyllum japonicum (I)
 * Cercis canadensis var. canadensis (N)
 * Chaenomeles speciosa (I)
 * Chaenorhinum minus (I)
 * Chaerophyllum procumbens var. procumbens (N)
 * Chaerophyllum procumbens var. shortii (N)
 * Chaerophyllum tainturieri var. tainturieri (N)
 * Chaiturus marrubiastrum (I)
 * Chamaecrista fasciculata var. fasciculata (N)
 * Chamaecrista nictitans ssp. nictitans var. nictitans (N)
 * Chamaecrista nictitans ssp. nictitans (N)
 * Chamaedaphne calyculata (N)
 * Chamaelirium luteum (N)
 * Chamaemelum mixtum (I)
 * Chamaemelum nobile (I)
 * Chamaesyce humistrata (N)
 * Chamaesyce maculata (N)
 * Chamaesyce nutans (N)
 * Chamaesyce polygonifolia (N)
 * Chamaesyce prostrata (N)
 * Chamaesyce serpens (N)
 * Chamaesyce vermiculata (N)
 * Chamerion angustifolium ssp. circumvagum (N)
 * Chasmanthium latifolium (N)
 * Chelidonium majus var. majus (I)
 * Chelone glabra (N)
 * Chenopodium album var. missouriense (N)
 * Chenopodium album var. album (I)
 * Chenopodium ambrosioides var. ambrosioides (I)
 * Chenopodium berlandieri var. bushianum (N)
 * Chenopodium berlandieri var. zschackii (N)
 * Chenopodium botrys (I)
 * Chenopodium capitatum (N)
 * Chenopodium glaucum (I)
 * Chenopodium glaucum (N)
 * Chenopodium humile (I)
 * Chenopodium humile (N)
 * Chenopodium incanum var. incanum (N)
 * Chenopodium murale (I)
 * Chenopodium polyspermum var. acutifolium (I)
 * Chenopodium pratericola (N)
 * Chenopodium pumilio (I)
 * Chenopodium simplex (N)
 * Chenopodium standleyanum (N)
 * Chenopodium subglabrum (N)
 * Chenopodium urbicum (I)
 * Chenopodium vulvaria (I)
 * Chimaphila maculata (N)
 * Chimaphila umbellata ssp. cisatlantica (N)
 * Chionanthus virginicus (N)
 * Chloris verticillata (N)
 * Chloris virgata (N)
 * Chorispora tenella (I)
 * Chrysanthemum × morifolium (I)
 * Chrysogonum virginianum var. virginianum (N)
 * Chrysopsis mariana (N)
 * Chrysosplenium americanum (N)
 * Cichorium intybus (I)
 * Cicuta bulbifera (N)
 * Cicuta maculata var. maculata (N)
 * Cinna arundinacea (N)
 * Cinna latifolia (N)
 * Circaea alpina ssp. alpina (N)
 * Circaea × intermedia (N)
 * Circaea lutetiana ssp. canadensis (N)
 * Cirsium altissimum (N) --   tall thistle or roadside thistle
 * Cirsium arvense (I) --   creeping thistle
 * Cirsium canescens (N) --  Platte thistle, prairie thistle
 * Cirsium carolinianum (N) --  Carolina thistle, soft thistle
 * Cirsium discolor (N) --  field thistle, pasture thistle
 * Cirsium muticum (N) --  swamp thistle
 * Cirsium pumilum (N) --  pasture thistle
 * Cirsium vulgare (I) --  spear thistle, bull thistle, or common thistle
 * Citrullus lanatus var. lanatus (I)
 * Cladium mariscoides (N)
 * Cladrastis kentukea (N)
 * Clarkia pulchella (N)
 * Claytonia caroliniana var. caroliniana (N)
 * Claytonia virginica var. virginica (N)
 * Clematis occidentalis var. occidentalis (N)
 * Clematis terniflora (I)
 * Clematis viorna (N)
 * Clematis virginiana (N)
 * Cleome hassleriana (I)
 * Cleome serrulata (N)
 * Clinopodium arkansanum (N)
 * Clinopodium vulgare (N)
 * Clintonia borealis (N)
 * Clintonia umbellulata (N)
 * Clitoria mariana (N)
 * Coix lacryma-jobi (I)
 * Collinsia verna (N)
 * Collinsonia canadensis (N)
 * Collinsonia verticillata (N)
 * Collomia linearis (N)
 * Colutea arborescens (I)
 * Comandra umbellata ssp. umbellata (N)
 * Comarum palustre (N)
 * Commelina communis (I)
 * Commelina diffusa var. diffusa (N)
 * Commelina virginica (N)
 * Comptonia peregrina (N)
 * Conioselinum chinense (N)
 * Conium maculatum (I)
 * Conoclinium coelestinum (N)
 * Conopholis americana (N)
 * Conringia orientalis (I)
 * Consolida ajacis (I)
 * Consolida regalis (I)
 * Convallaria majalis (I)
 * Convolvulus arvensis (I)
 * Conyza canadensis var. canadensis (N)
 * Conyza canadensis var. pusilla (N)
 * Conyza ramosissima (N)
 * Coptis trifolia (N)
 * Corallorhiza maculata var. maculata (N)
 * Corallorhiza odontorhiza var. odontorhiza (N)
 * Corallorhiza trifida (N)
 * Corallorhiza wisteriana (N)
 * Coreopsis grandiflora var. harveyana (N) --  large-flowered tickseed
 * Coreopsis lanceolata (N) --  lance-leaved tickseed
 * Coreopsis major (N) --
 * Coreopsis tinctoria var. tinctoria (N) --  golden tickseed
 * Coreopsis tripteris (N) --  tall tickseed
 * Coreopsis verticillata (N) --  whorled tickseed
 * Coriandrum sativum (I)
 * Corispermum americanum var. americanum (N)
 * Corispermum pallasii (I)
 * Corispermum pallasii (N)
 * Cornus alternifolia (N)
 * Cornus amomum (N)
 * Cornus × arnoldiana (N)
 * Cornus canadensis (N)
 * Cornus drummondii (N)
 * Cornus florida (N)
 * Cornus obliqua (N)
 * Cornus racemosa (N)
 * Cornus rugosa (N)
 * Cornus sericea ssp. sericea (N)
 * Coronilla scorpioides (I)
 * Coronopus didymus (I)
 * Corydalis aurea (N)
 * Corydalis flavula (N)
 * Corydalis sempervirens (N)
 * Corylus americana (N)
 * Corylus cornuta var. cornuta (N)
 * Cosmos bipinnatus (I)
 * Cotinus coggygria (I)
 * Cotoneaster divaricatus (I)
 * Cotoneaster simonsii (I)
 * Crataegus × anomala (N)
 * Crataegus apiomorpha (N)
 * Crataegus arborea (N)
 * Crataegus ater (N)
 * Crataegus beata (N)
 * Crataegus brainerdii (N)
 * Crataegus calpodendron (N)
 * Crataegus chrysocarpa var. chrysocarpa (N)
 * Crataegus coleae (N)
 * Crataegus compacta (N)
 * Crataegus compta (N)
 * Crataegus corusca (N)
 * Crataegus crus-galli (N)
 * Crataegus disperma (N)
 * Crataegus dissona (N)
 * Crataegus engelmannii (N)
 * Crataegus flabellata (N) --  fanleaf hawthorn
 * Crataegus holmesiana (N)
 * Crataegus × hudsonica (N)
 * Crataegus × immanis (N)
 * Crataegus indicens (N)
 * Crataegus intricata (N)
 * Crataegus iracunda (N) --  passionate hawthorn
 * Crataegus irrasa (N)
 * Crataegus jesupii (N)
 * Crataegus lucorum (N)
 * Crataegus macrosperma (N) --  bigfruit hawthorn
 * Crataegus margarettiae (N)
 * Crataegus mollis (N)
 * Crataegus monogyna (I)
 * Crataegus nitida (N)
 * Crataegus pedicellata (N)
 * Crataegus pennsylvanica (N)
 * Crataegus persimilis (N)
 * Crataegus phaenopyrum (N)
 * Crataegus pringlei (N)
 * Crataegus prona (N)
 * Crataegus pruinosa (N)
 * Crataegus punctata (N)
 * Crataegus scabrida (N)
 * Crataegus schuettei (N) --  royal hawthorn
 * Crataegus submollis (N)
 * Crataegus suborbiculata (N)
 * Crataegus succulenta (N)
 * Crataegus tanuphylla (N)
 * Crataegus uniflora (N)
 * Crepis biennis (I)
 * Crepis capillaris (I)
 * Crepis nicaeensis (I)
 * Crepis pulchra (I)
 * Crepis setosa (I)
 * Crepis tectorum (I)
 * Crotalaria sagittalis (N)
 * Croton capitatus var. capitatus (N)
 * Croton glandulosus var. septentrionalis (N)
 * Croton monanthogynus (N)
 * Cruciata pedemontana (I)
 * Crypsis schoenoides (I)
 * Cryptotaenia canadensis (N)
 * Cucumis melo (I)
 * Cucumis sativus (I)
 * Cucurbita foetidissima (N)
 * Cucurbita maxima (I)
 * Cucurbita pepo (N)
 * Cucurbita pepo var. pepo (I)
 * Cunila origanoides (N)
 * Cuphea viscosissima (N)
 * Cuscuta cephalanthi (N)
 * Cuscuta compacta var. compacta (N)
 * Cuscuta coryli (N)
 * Cuscuta epilinum (I)
 * Cuscuta epithymum (I)
 * Cuscuta glomerata (N)
 * Cuscuta gronovii var. gronovii (N)
 * Cuscuta pentagona var. pentagona (N)
 * Cuscuta polygonorum (N)
 * Cuscuta suaveolens (I)
 * Cyclachaena xanthifolia (N)
 * Cycloloma atriplicifolium (N)
 * Cydonia oblonga (I)
 * Cymbalaria muralis (I)
 * Cynanchum laeve (N)
 * Cynanchum louiseae (I)
 * Cynodon dactylon (I)
 * Cynoglossum officinale (I)
 * Cynoglossum virginianum var. boreale (N)
 * Cynoglossum virginianum var. virginianum (N)
 * Cynosurus cristatus (I)
 * Cynosurus echinatus (I)
 * Cyperus acuminatus (N) --  tapertip flatsedge
 * Cyperus amuricus (I)
 * Cyperus bipartitus (N) --  slender flatsedge, river cyperus
 * Cyperus compressus (N) --  annual sedge
 * Cyperus diandrus (N)
 * Cyperus echinatus (N)
 * Cyperus erythrorhizos (N) --  redroot flatsedge
 * Cyperus esculentus (N) --  tiger nut, atadwe, yellow nutsedge, and earth almond
 * Cyperus esculentus var. leptostachyus (I)
 * Cyperus flavescens (N)
 * Cyperus houghtonii (N)
 * Cyperus iria (I) --  rice flat sedge
 * Cyperus lancastriensis (N) --
 * Cyperus lupulinus ssp. lupulinus (N) --  Great Plains flatsedge
 * Cyperus lupulinus ssp. macilentus (N)
 * Cyperus odoratus (N) --  fragrant flatsedge
 * Cyperus refractus (N)
 * Cyperus retrofractus (N)
 * Cyperus schweinitzii (N)
 * Cyperus squarrosus (N) --  bearded flatsedge
 * Cyperus strigosus (N) --   false nutsedge and straw-colored flatsedge
 * Cypripedium acaule (N)
 * Cypripedium × andrewsii var. andrewsii (N)
 * Cypripedium × andrewsii var. landonii (N)
 * Cypripedium candidum (N)
 * Cypripedium parviflorum var. parviflorum (N)
 * Cypripedium parviflorum var. pubescens (N)
 * Cypripedium reginae (N)
 * Cyrtomium falcatum (I)
 * Cystopteris bulbifera (N)
 * Cystopteris fragilis (N)
 * Cystopteris × illinoensis (N)
 * Cystopteris protrusa (N)
 * Cystopteris tennesseensis (N)
 * Cystopteris tenuis (N)
 * Cystopteris × wagneri (N)
 * Cytisus scoparius var. scoparius (I)

D

 * Dactylis glomerata ssp. glomerata (I)
 * Dactyloctenium aegyptium (I)
 * Dactylorhiza viridis (N)
 * Dalea leporina (N)
 * Dalea purpurea var. purpurea (N)
 * Dalibarda repens (N)
 * Danthonia compressa (N)
 * Danthonia spicata (N)
 * Daphne mezereum (I)
 * Dasiphora fruticosa ssp. floribunda (N)
 * Dasistoma macrophylla (N)
 * Datura stramonium (I)
 * Datura wrightii (N)
 * Daucus carota (I)
 * Decodon verticillatus (N)
 * Delphinium exaltatum (N)
 * Delphinium tricorne (N)
 * Dennstaedtia punctilobula (N)
 * Deparia acrostichoides (N)
 * Deschampsia cespitosa (N)
 * Deschampsia danthonioides (N)
 * Deschampsia flexuosa var. flexuosa (N)
 * Descurainia pinnata ssp. brachycarpa (N)
 * Descurainia sophia (I)
 * Desmanthus illinoensis (N)
 * Desmodium canadense (N)
 * Desmodium canescens (N)
 * Desmodium ciliare var. ciliare (N)
 * Desmodium cuspidatum var. cuspidatum (N)
 * Desmodium cuspidatum var. longifolium (N)
 * Desmodium glutinosum (N)
 * Desmodium illinoense (N)
 * Desmodium laevigatum (N)
 * Desmodium marilandicum (N)
 * Desmodium nudiflorum (N)
 * Desmodium obtusum (N)
 * Desmodium paniculatum var. paniculatum (N)
 * Desmodium pauciflorum (N)
 * Desmodium perplexum (N)
 * Desmodium rotundifolium (N)
 * Desmodium sessilifolium (N)
 * Desmodium viridiflorum (N)
 * Dianthus armeria (I)
 * Dianthus barbatus (I)
 * Dianthus deltoides (I)
 * Dianthus plumarius (I)
 * Diarrhena americana (N)
 * Diarrhena obovata (N)
 * Dicentra canadensis (N)
 * Dicentra cucullaria (N)
 * Dicentra eximia (N)
 * Dichanthelium acuminatum var. acuminatum (N)
 * Dichanthelium acuminatum var. fasciculatum (N)
 * Dichanthelium acuminatum var. lindheimeri (N)
 * Dichanthelium boreale (N)
 * Dichanthelium boscii (N)
 * Dichanthelium clandestinum (N)
 * Dichanthelium commutatum (N)
 * Dichanthelium depauperatum (N)
 * Dichanthelium dichotomum var. dichotomum (N)
 * Dichanthelium latifolium (N)
 * Dichanthelium laxiflorum (N)
 * Dichanthelium leibergii (N)
 * Dichanthelium linearifolium (N)
 * Dichanthelium longiligulatum (N)
 * Dichanthelium meridionale (N)
 * Dichanthelium oligosanthes var. oligosanthes (N)
 * Dichanthelium oligosanthes var. scribnerianum (N)
 * Dichanthelium ovale var. addisonii (N)
 * Dichanthelium sabulorum var. patulum (N)
 * Dichanthelium sabulorum var. thinium (N)
 * Dichanthelium sphaerocarpon var. isophyllum (N)
 * Dichanthelium sphaerocarpon var. sphaerocarpon (N)
 * Dichanthelium spretum (N)
 * Dichanthelium villosissimum var. praecocius (N)
 * Dichondra carolinensis (N)
 * Diervilla lonicera (N)
 * Digitalis grandiflora (I)
 * Digitalis lanata (I)
 * Digitalis lutea (I)
 * Digitalis purpurea ssp. purpurea (I)
 * Digitaria ciliaris (N)
 * Digitaria cognata (N)
 * Digitaria filiformis (N)
 * Digitaria ischaemum (I)
 * Digitaria sanguinalis (N)
 * Diodia teres var. teres (N)
 * Diodia virginiana var. virginiana (N)
 * Dioscorea polystachya (I)
 * Dioscorea quaternata (N)
 * Dioscorea villosa (N)
 * Diospyros virginiana (N)
 * Diplazium pycnocarpon (N)
 * Diplotaxis muralis (I)
 * Diplotaxis tenuifolia (I)
 * Dipsacus fullonum (I)
 * Dipsacus laciniatus (I)
 * Dipsacus sativus (I)
 * Dirca palustris (N)
 * Distichlis spicata (N)
 * Dodecatheon meadia ssp. meadia (N)
 * Doellingeria infirma (N)
 * Doellingeria umbellata var. umbellata (N)
 * Draba brachycarpa (N)
 * Draba cuneifolia var. cuneifolia (N)
 * Draba reptans (N)
 * Draba verna (I)
 * Dracocephalum parviflorum (N)
 * Drosera intermedia (N)
 * Drosera rotundifolia var. rotundifolia (N)
 * Dryopteris × benedictii (N)
 * Dryopteris × boottii (N)
 * Dryopteris carthusiana (N)
 * Dryopteris clintoniana (N)
 * Dryopteris cristata (N)
 * Dryopteris goldieana (N)
 * Dryopteris intermedia (N)
 * Dryopteris marginalis (N)
 * Dryopteris × mickelii (N)
 * Dryopteris × neowherryi (N)
 * Dryopteris × pittsfordensis (N)
 * Dryopteris × slossoniae (N)
 * Dryopteris × triploidea (N)
 * Dryopteris × uliginosa (N)
 * Duchesnea indica (I)
 * Dulichium arundinaceum var. arundinaceum (N)
 * Dyssodia papposa (N)

E

 * Echinacea purpurea (N)
 * Echinochloa crus-galli (I)
 * Echinochloa frumentacea (I)
 * Echinochloa muricata var. microstachya (N)
 * Echinochloa muricata var. muricata (N)
 * Echinochloa walteri (N)
 * Echinocystis lobata (N)
 * Echinodorus berteroi (N)
 * Echium vulgare (I)
 * Eclipta prostrata (N)
 * Egeria densa (I)
 * Elaeagnus angustifolia (I)
 * Elaeagnus multiflora (I)
 * Elaeagnus umbellata var. parvifolia (I)
 * Elatine brachysperma (N)
 * Eleocharis acicularis var. acicularis (N)
 * Eleocharis compressa var. compressa (N)
 * Eleocharis elliptica (N)
 * Eleocharis engelmannii (N)
 * Eleocharis erythropoda (N)
 * Eleocharis geniculata (N)
 * Eleocharis intermedia (N)
 * Eleocharis obtusa (N)
 * Eleocharis olivacea var. olivacea (N)
 * Eleocharis ovata (N)
 * Eleocharis palustris var. palustris (N)
 * Eleocharis parvula (N)
 * Eleocharis quadrangulata (N)
 * Eleocharis quinqueflora (N)
 * Eleocharis rostellata (N)
 * Eleocharis tenuis var. tenuis (N)
 * Eleocharis tenuis var. verrucosa (N)
 * Eleocharis wolfii (N)
 * Elephantopus carolinianus (N)
 * Eleusine indica (I)
 * Ellisia nyctelea (N)
 * Elodea canadensis (N)
 * Elodea nuttallii (N)
 * Elymus canadensis (N)
 * Elymus hystrix var. bigeloviana (N)
 * Elymus hystrix var. hystrix (N)
 * Elymus repens (I)
 * Elymus riparius (N)
 * Elymus submuticus (N)
 * Elymus trachycaulus ssp. subsecundus (N)
 * Elymus trachycaulus ssp. trachycaulus (N)
 * Elymus villosus (N)
 * Elymus virginicus var. virginicus (N)
 * Enemion biternatum (N)
 * Epifagus virginiana (N)
 * Epigaea repens (N)
 * Epilobium ciliatum ssp. ciliatum (N)
 * Epilobium ciliatum ssp. glandulosum (N)
 * Epilobium coloratum (N)
 * Epilobium hirsutum (I)
 * Epilobium leptophyllum (N)
 * Epilobium parviflorum (I)
 * Epilobium strictum (N)
 * Epilobium × wisconsinense (N)
 * Epipactis helleborine (I)
 * Equisetum arvense (N)
 * Equisetum × ferrissii (N)
 * Equisetum fluviatile (N)
 * Equisetum hyemale var. affine (N)
 * Equisetum laevigatum (N)
 * Equisetum × mackaii (N)
 * Equisetum × nelsonii (N)
 * Equisetum sylvaticum (N)
 * Equisetum variegatum var. variegatum (N)
 * Eragrostis capillaris (N)
 * Eragrostis cilianensis (I)
 * Eragrostis curvula (I)
 * Eragrostis frankii (N)
 * Eragrostis hirsuta (N)
 * Eragrostis hypnoides (N)
 * Eragrostis minor (I)
 * Eragrostis pectinacea var. miserrima (N)
 * Eragrostis pectinacea var. pectinacea (N)
 * Eragrostis pilosa (N)
 * Eragrostis spectabilis (N)
 * Eragrostis trichodes (N)
 * Eranthis hyemalis (I)
 * Erechtites hieraciifolia var. hieraciifolia (N)
 * Erica tetralix (I)
 * Erigenia bulbosa (N)
 * Erigeron annuus (N)
 * Erigeron philadelphicus var. philadelphicus (N)
 * Erigeron pulchellus var. brauniae (N)
 * Erigeron pulchellus var. pulchellus (N)
 * Erigeron strigosus var. strigosus (N)
 * Eriocaulon aquaticum (N)
 * Eriochloa contracta (N)
 * Eriophorum gracile var. gracile (N)
 * Eriophorum virginicum (N)
 * Eriophorum viridicarinatum (N)
 * Erodium cicutarium ssp. cicutarium (I)
 * Erucastrum gallicum (I)
 * Eryngium yuccifolium var. yuccifolium (N)
 * Erysimum capitatum var. capitatum (N)
 * Erysimum cheiranthoides (I)
 * Erysimum inconspicuum var. inconspicuum (N)
 * Erysimum repandum (I)
 * Erythronium albidum (N)
 * Erythronium americanum ssp. americanum (N)
 * Erythronium rostratum (N)
 * Eschscholzia californica ssp. californica (N)
 * Eubotrys recurva (N)
 * Euonymus alatus var. alatus (I)
 * Euonymus americanus (N)
 * Euonymus atropurpureus var. atropurpureus (N)
 * Euonymus europaeus (I)
 * Euonymus fortunei var. radicans (I)
 * Euonymus obovatus (N)
 * Eupatoriadelphus fistulosus (N)
 * Eupatoriadelphus maculatus var. maculatus (N)
 * Eupatorium album var. album (N)
 * Eupatorium altissimum (N)
 * Eupatorium godfreyanum (N) (a hybrid of Eupatorium rotundifolium and Eupatorium sessilifolium)
 * Eupatorium hyssopifolium var. laciniatum (N)
 * Eupatorium perfoliatum var. perfoliatum (N)
 * Eupatorium purpureum var. purpureum (N)
 * Eupatorium rotundifolium var. ovatum (N)
 * Eupatorium rotundifolium var. rotundifolium (N)
 * Eupatorium serotinum (N)
 * Eupatorium sessilifolium var. sessilifolium (N)
 * Euphorbia commutata (N)
 * Euphorbia corollata (N)
 * Euphorbia cyathophora (N)
 * Euphorbia cyparissias (I)
 * Euphorbia davidii (I)
 * Euphorbia dentata (I)
 * Euphorbia dentata var. dentata (N)
 * Euphorbia esula var. esula (I)
 * Euphorbia falcata (I)
 * Euphorbia helioscopia (I)
 * Euphorbia lathyris (I)
 * Euphorbia marginata (N)
 * Euphorbia peplus (I)
 * Euphorbia platyphyllos (I)
 * Euphorbia purpurea (N)
 * Euphorbia spathulata (N)
 * Eurybia divaricata (N)
 * Eurybia macrophylla (N)
 * Eurybia schreberi (N)
 * Eurybia surculosa (N)
 * Euthamia graminifolia var. graminifolia (N)
 * Euthamia gymnospermoides (N)

F

 * Fagopyrum esculentum (I)
 * Fagus grandifolia (N)
 * Fagus sylvatica (I)
 * Fatoua villosa (I)
 * Festuca brevipila (I)
 * Festuca filiformis (I)
 * Festuca rubra (I)
 * Festuca rubra ssp. rubra (N)
 * Festuca subverticillata (N)
 * Filago vulgaris (I)
 * Filipendula rubra (N)
 * Filipendula ulmaria ssp. ulmaria (I)
 * Fimbristylis autumnalis (N)
 * Fleischmannia incarnata (N)
 * Floerkea proserpinacoides (N)
 * Foeniculum vulgare (I)
 * Fontanesia phillyreoides ssp. fortunei (I)
 * Forsythia × intermedia (I)
 * Forsythia suspensa (I)
 * Fragaria vesca ssp. americana (N)
 * Fragaria vesca ssp. vesca (N)
 * Fragaria virginiana ssp. grayana (N)
 * Fragaria virginiana ssp. virginiana (N)
 * Frangula alnus (I)
 * Frangula alnus (N)
 * Frangula caroliniana (N)
 * Frasera caroliniensis (N)
 * Fraxinus americana (N)
 * Fraxinus excelsior (I)
 * Fraxinus nigra (N)
 * Fraxinus pennsylvanica (N)
 * Fraxinus profunda (N)
 * Fraxinus quadrangulata (N)
 * Froelichia floridana var. campestris (N)
 * Froelichia gracilis (N)
 * Fumaria officinalis ssp. officinalis (I)

G

 * Gaillardia pulchella var. pulchella (N)
 * Galactia volubilis (N)
 * Galanthus elwesii (I)
 * Galanthus nivalis (I)
 * Galax urceolata (N)
 * Galearis spectabilis (N)
 * Galeopsis bifida (I)
 * Galeopsis ladanum var. ladanum (I)
 * Galeopsis tetrahit var. tetrahit (I)
 * Galinsoga parviflora (I)
 * Galinsoga quadriradiata (I)
 * Galium aparine (N)
 * Galium asprellum (N)
 * Galium boreale (N)
 * Galium circaezans var. hypomalacum (N)
 * Galium concinnum (N)
 * Galium labradoricum (N)
 * Galium lanceolatum (N)
 * Galium mollugo (I)
 * Galium obtusum ssp. obtusum (N)
 * Galium odoratum (I)
 * Galium palustre (N)
 * Galium pilosum var. pilosum (N)
 * Galium tinctorium (N)
 * Galium trifidum ssp. trifidum (N)
 * Galium triflorum (N)
 * Galium verum var. verum (I)
 * Gamochaeta purpurea (N)
 * Gaultheria hispidula (N)
 * Gaultheria procumbens (N)
 * Gaura biennis (N)
 * Gaura longiflora (N)
 * Gaura mollis (N)
 * Gaylussacia baccata (N)
 * Genista tinctoria (I)
 * Gentiana alba (N)
 * Gentiana andrewsii var. andrewsii (N)
 * Gentiana × billingtonii (N)
 * Gentiana clausa (N)
 * Gentiana puberulenta (N)
 * Gentiana saponaria var. saponaria (N)
 * Gentiana villosa (N)
 * Gentianella quinquefolia ssp. occidentalis (N)
 * Gentianopsis crinita (N)
 * Gentianopsis virgata ssp. victorinii (N)
 * Gentianopsis virgata ssp. virgata (N)
 * Geranium bicknellii (N)
 * Geranium carolinianum var. carolinianum (N)
 * Geranium columbinum (I)
 * Geranium dissectum (I)
 * Geranium maculatum (N)
 * Geranium molle (I)
 * Geranium pusillum (I)
 * Geranium robertianum (I)
 * Geranium robertianum ssp. robertianum (N)
 * Geranium sanguineum (I)
 * Geum aleppicum (N)
 * Geum canadense var. canadense (N)
 * Geum laciniatum var. laciniatum (N)
 * Geum rivale (N)
 * Geum urbanum (I)
 * Geum vernum (N)
 * Geum virginianum (N)
 * Gilia capitata ssp. capitata (N)
 * Gillenia stipulata (N)
 * Gillenia trifoliata (N)
 * Gladiolus × gandavensis (I)
 * Glandularia canadensis (N)
 * Glandularia × hybrida (I)
 * Glebionis segetum (I)
 * Glechoma hederacea (I)
 * Gleditsia triacanthos (N)
 * Glyceria acutiflora (N)
 * Glyceria borealis (N)
 * Glyceria canadensis (N)
 * Glyceria grandis var. grandis (N)
 * Glyceria melicaria (N)
 * Glyceria septentrionalis (N)
 * Glyceria striata (N)
 * Glycine max (I)
 * Gnaphalium uliginosum (I)
 * Gomphrena globosa (I)
 * Goodyera pubescens (N)
 * Goodyera repens (N)
 * Goodyera tesselata (N)
 * Gratiola neglecta (N)
 * Gratiola virginiana var. virginiana (N)
 * Gratiola viscidula (N)
 * Grindelia lanceolata var. lanceolata (N)
 * Grindelia squarrosa var. serrulata (N)
 * Grindelia squarrosa var. squarrosa (N)
 * Guizotia abyssinica (I)
 * Gutierrezia texana var. texana (N)
 * Gymnocarpium appalachianum (N)
 * Gymnocarpium × brittonianum (N)
 * Gymnocarpium dryopteris (N)
 * Gymnocladus dioicus (N)
 * Gymnopogon ambiguus (N)
 * Gypsophila paniculata (I)
 * Gypsophila scorzonerifolia (I)

H

 * Hackelia deflexa var. americana (N)
 * Hackelia virginiana (N)
 * Halesia tetraptera var. tetraptera (N)
 * Hamamelis virginiana (N)
 * Hasteola suaveolens (N)
 * Hedeoma hispida (N)
 * Hedeoma pulegioides (N)
 * Hedera helix (I)
 * Helenium amarum var. amarum (N)
 * Helenium autumnale var. autumnale (N)
 * Helenium flexuosum (N)
 * Helianthemum bicknellii (N)
 * Helianthemum canadense (N)
 * Helianthus × ambiguus (N)
 * Helianthus angustifolius (N)
 * Helianthus annuus (N)
 * Helianthus × brevifolius (N)
 * Helianthus × cinereus (N)
 * Helianthus decapetalus (N)
 * Helianthus divaricatus (N)
 * Helianthus × divariserratus (N)
 * Helianthus × doronicoides (N)
 * Helianthus giganteus (N)
 * Helianthus × glaucus (N)
 * Helianthus grosseserratus (N)
 * Helianthus hirsutus (N)
 * Helianthus × intermedius (N)
 * Helianthus × kellermanii (N)
 * Helianthus × laetiflorus (N)
 * Helianthus × luxurians (N)
 * Helianthus maximiliani (N)
 * Helianthus microcephalus (N)
 * Helianthus mollis (N)
 * Helianthus × multiflorus (N)
 * Helianthus occidentalis ssp. occidentalis (N)
 * Helianthus petiolaris ssp. petiolaris (N)
 * Helianthus salicifolius (N)
 * Helianthus strumosus (N)
 * Helianthus tuberosus (N)
 * Heliopsis helianthoides var. helianthoides (N)
 * Heliopsis helianthoides var. occidentalis (N)
 * Heliotropium europaeum (I)
 * Heliotropium indicum (I)
 * Helleborus viridis (I)
 * Hemerocallis fulva (I)
 * Hemerocallis lilioasphodelus (I)
 * Hepatica nobilis var. acuta (N)
 * Hepatica nobilis var. obtusa (N)
 * Heracleum maximum (N)
 * Hesperis matronalis (I)
 * Hesperostipa spartea (N)
 * Heteranthera dubia (N)
 * Heteranthera reniformis (N)
 * Heterotheca camporum var. camporum (N)
 * Heuchera americana var. americana (N)
 * Heuchera americana var. hirsuticaulis (N)
 * Heuchera americana var. hispida (N)
 * Heuchera longiflora (N)
 * Heuchera parviflora var. parviflora (N)
 * Heuchera villosa var. villosa (N)
 * Hexalectris spicata var. spicata (N)
 * Hibiscus laevis (N)
 * Hibiscus moscheutos (N)
 * Hibiscus syriacus (I)
 * Hibiscus trionum (I)
 * Hieracium aurantiacum (I)
 * Hieracium caespitosum (I)
 * Hieracium × flagellare var. flagellare (I)
 * Hieracium × floribundum (I)
 * Hieracium greenii (N)
 * Hieracium gronovii (N)
 * Hieracium kalmii var. fasciculatum (N)
 * Hieracium kalmii var. kalmii (N)
 * Hieracium longipilum (N)
 * Hieracium paniculatum (N)
 * Hieracium pilosella var. pilosella (I)
 * Hieracium piloselloides (I)
 * Hieracium scabrum var. scabrum (N)
 * Hieracium venosum (N)
 * Hierochloe hirta ssp. arctica (N)
 * Holcus lanatus (I)
 * Holosteum umbellatum (I)
 * Hordeum brachyantherum ssp. brachyantherum (N)
 * Hordeum jubatum ssp. jubatum (N)
 * Hordeum marinum ssp. gussonianum (I)
 * Hordeum pusillum (N)
 * Hordeum vulgare (I)
 * Hosta lancifolia (I)
 * Hosta ventricosa (I)
 * Hottonia inflata (N)
 * Houstonia caerulea (N)
 * Houstonia canadensis (N)
 * Houstonia longifolia (N)
 * Houstonia purpurea var. calycosa (N)
 * Houstonia purpurea var. purpurea (N)
 * Hudsonia tomentosa var. tomentosa (N)
 * Humulus japonicus (I)
 * Humulus lupulus var. lupuloides (N)
 * Humulus lupulus var. pubescens (N)
 * Humulus lupulus var. lupulus (I)
 * Huperzia × bartleyi (N)
 * Huperzia × buttersii (N)
 * Huperzia lucidula (N)
 * Huperzia porophila (N)
 * Hyacinthoides non-scripta (I)
 * Hybanthus concolor (N)
 * Hydrangea arborescens (N)
 * Hydrastis canadensis (N)
 * Hydrocotyle americana (N)
 * Hydrocotyle ranunculoides (N)
 * Hydrocotyle sibthorpioides (I)
 * Hydrocotyle umbellata (N)
 * Hydrophyllum appendiculatum (N)
 * Hydrophyllum canadense (N)
 * Hydrophyllum macrophyllum (N)
 * Hydrophyllum virginianum var. virginianum (N)
 * Hylotelephium telephioides (N)
 * Hylotelephium telephium ssp. telephium (I)
 * Hypericum ascyron (N)
 * Hypericum boreale (N)
 * Hypericum canadense (N)
 * Hypericum drummondii (N)
 * Hypericum ellipticum (N)
 * Hypericum gentianoides (N)
 * Hypericum gymnanthum (N)
 * Hypericum hypericoides ssp. multicaule (N)
 * Hypericum kalmianum (N)
 * Hypericum majus (N)
 * Hypericum mutilum (N)
 * Hypericum perforatum (I)
 * Hypericum prolificum (N)
 * Hypericum punctatum (N)
 * Hypericum sphaerocarpum (N)
 * Hypericum virgatum (N)
 * Hypochaeris glabra (I)
 * Hypochaeris radicata (I)
 * Hypoxis hirsuta (N)

I

 * Iberis umbellata (I)
 * Ilex crenata (I)
 * Ilex mucronata (N)
 * Ilex opaca var. opaca (N)
 * Ilex verticillata (N)
 * Impatiens balsamina (I)
 * Impatiens capensis (N)
 * Impatiens pallida (N)
 * Inula helenium (I)
 * Iodanthus pinnatifidus (N)
 * Ionactis linariifolius (N)
 * Ipomoea coccinea (I)
 * Ipomoea hederacea (I)
 * Ipomoea lacunosa (N)
 * Ipomoea pandurata (N)
 * Ipomoea purpurea (I)
 * Ipomopsis rubra (N)
 * Iris brevicaulis (N)
 * Iris cristata (N)
 * Iris fulva (N)
 * Iris germanica (I)
 * Iris pseudacorus (I)
 * Iris verna var. smalliana (N)
 * Iris versicolor (N)
 * Iris virginica var. shrevei (N)
 * Isoetes appalachiana (N)
 * Isoetes engelmannii (N)
 * Isoetes tenella (N)
 * Isotria medeoloides (N)
 * Isotria verticillata (N)
 * Iva annua var. annua (N)

J

 * Jacquemontia tamnifolia (N)
 * Jeffersonia diphylla (N)
 * Juglans cinerea (N)
 * Juglans nigra (N)
 * Juncus acuminatus (N)
 * Juncus alpinoarticulatus ssp. nodulosus (N)
 * Juncus anthelatus (N)
 * Juncus arcticus ssp. littoralis (N)
 * Juncus articulatus (N)
 * Juncus biflorus (N)
 * Juncus brachycarpus (N)
 * Juncus brachycephalus (N)
 * Juncus bufonius var. bufonius (N)
 * Juncus canadensis (N)
 * Juncus compressus (I)
 * Juncus dichotomus (N)
 * Juncus diffusissimus (N)
 * Juncus dudleyi (N)
 * Juncus effusus var. decipiens (N)
 * Juncus effusus var. pylaei (N)
 * Juncus effusus var. solutus (N)
 * Juncus gerardii var. gerardii (N)
 * Juncus greenei (N)
 * Juncus interior var. interior (N)
 * Juncus marginatus (N)
 * Juncus nodosus var. nodosus (N)
 * Juncus secundus (N)
 * Juncus × stuckeyi (N)
 * Juncus subcaudatus var. subcaudatus (N)
 * Juncus tenuis (N)
 * Juncus torreyi (N)
 * Juniperus communis var. depressa (N)
 * Juniperus virginiana var. virginiana (N)
 * Justicia americana (N)

K

 * Kalmia latifolia (N)
 * Kerria japonica (I)
 * Kickxia elatine (I)
 * Kickxia spuria (I)
 * Koeleria macrantha (N)
 * Koelreuteria paniculata (I)
 * Krigia biflora var. biflora (N)
 * Krigia dandelion (N)
 * Krigia virginica (N)
 * Kummerowia stipulacea (I)
 * Kummerowia striata (I)
 * Kyllinga pumila (N)

L

 * Lablab purpureus (I)
 * Lactuca biennis (N)
 * Lactuca canadensis (N)
 * Lactuca floridana var. floridana (N)
 * Lactuca floridana var. villosa (N)
 * Lactuca hirsuta var. sanguinea (N)
 * Lactuca × morssii (N)
 * Lactuca saligna (I)
 * Lactuca sativa (I)
 * Lactuca serriola (I)
 * Lactuca tatarica var. pulchella (N)
 * Lamium album (I)
 * Lamium amplexicaule (I)
 * Lamium maculatum (I)
 * Lamium purpureum var. purpureum (I)
 * Laportea canadensis (N)
 * Lappula squarrosa (I)
 * Lapsana communis (I)
 * Larix laricina (N)
 * Lathyrus japonicus var. maritimus (N)
 * Lathyrus japonicus var. parviflorus (N)
 * Lathyrus latifolius (I)
 * Lathyrus ochroleucus (N)
 * Lathyrus odoratus (I)
 * Lathyrus palustris (N)
 * Lathyrus pratensis (I)
 * Lathyrus tuberosus (I)
 * Lathyrus venosus (N)
 * Leavenworthia uniflora (N)
 * Lechea intermedia var. intermedia (N)
 * Lechea minor (N)
 * Lechea mucronata (N)
 * Lechea pulchella var. moniliformis (N)
 * Lechea pulchella var. pulchella (N)
 * Lechea racemulosa (N)
 * Lechea tenuifolia (N)
 * Ledum groenlandicum (N)
 * Leersia lenticularis (N)
 * Leersia oryzoides (N)
 * Leersia virginica (N)
 * Lemna minor (N)
 * Lemna minuta (N)
 * Lemna obscura (N)
 * Lemna perpusilla (N)
 * Lemna trisulca (N)
 * Lemna turionifera (N)
 * Lemna valdiviana (N)
 * Leontodon autumnalis ssp. autumnalis (I)
 * Leontodon autumnalis ssp. pratensis (I)
 * Leontodon hispidus ssp. danubialis (I)
 * Leontodon taraxacoides ssp. taraxacoides (I)
 * Leonurus cardiaca ssp. cardiaca (I)
 * Leonurus sibiricus (I)
 * Lepidium campestre (I)
 * Lepidium densiflorum var. densiflorum (N)
 * Lepidium perfoliatum (I)
 * Lepidium ramosissimum var. bourgeauanum (N)
 * Lepidium ruderale (I)
 * Lepidium sativum (I)
 * Lepidium virginicum var. virginicum (N)
 * Leptochloa fusca ssp. fascicularis (N)
 * Leptochloa panicea ssp. brachiata (N)
 * Lespedeza × acuticarpa (N)
 * Lespedeza bicolor (I)
 * Lespedeza × brittonii (N)
 * Lespedeza capitata (N)
 * Lespedeza cuneata (I)
 * Lespedeza formosa (I)
 * Lespedeza frutescens (N)
 * Lespedeza hirta ssp. hirta (N)
 * Lespedeza × nuttallii (N)
 * Lespedeza procumbens (N)
 * Lespedeza repens (N)
 * Lespedeza thunbergii (I)
 * Lespedeza violacea (N)
 * Lespedeza virginica (N)
 * Lesquerella globosa (N)
 * Leucanthemum maximum (I)
 * Leucanthemum vulgare (I)
 * Leucojum aestivum ssp. aestivum (I)
 * Leucospora multifida (N)
 * Levisticum officinale (I)
 * Liatris aspera var. aspera (N)
 * Liatris aspera var. intermedia (N)
 * Liatris cylindracea (N)
 * Liatris punctata var. punctata (N)
 * Liatris pycnostachya var. pycnostachya (N)
 * Liatris scariosa var. nieuwlandii (N)
 * Liatris spheroidea (N)
 * Liatris spicata var. spicata (N)
 * Liatris squarrosa var. squarrosa (N)
 * Liatris squarrulosa (N)
 * Ligusticum canadense (N)
 * Ligustrum obtusifolium (I)
 * Ligustrum ovalifolium (I)
 * Ligustrum vulgare (I)
 * Lilium canadense ssp. canadense (N)
 * Lilium canadense ssp. editorum (N)
 * Lilium lancifolium (I)
 * Lilium michiganense (N)
 * Lilium philadelphicum var. andinum (N)
 * Lilium philadelphicum var. philadelphicum (N)
 * Lilium superbum (N)
 * Linaria dalmatica ssp. dalmatica (I)
 * Linaria genistifolia (I)
 * Linaria vulgaris (I)
 * Lindera benzoin var. benzoin (N)
 * Lindera benzoin var. pubescens (N)
 * Lindernia dubia var. anagallidea (N)
 * Lindernia dubia var. dubia (N)
 * Linnaea borealis ssp. americana (N)
 * Linum grandiflorum (I)
 * Linum medium var. texanum (N)
 * Linum perenne (I)
 * Linum perenne (N)
 * Linum striatum (N)
 * Linum sulcatum var. sulcatum (N)
 * Linum usitatissimum (I)
 * Linum virginianum (N)
 * Liparis liliifolia (N)
 * Liparis loeselii (N)
 * Lipocarpha drummondii (N)
 * Lipocarpha micrantha (N)
 * Liquidambar styraciflua (N)
 * Liriodendron tulipifera (N)
 * Lithospermum canescens (N)
 * Lithospermum caroliniense var. croceum (N)
 * Lithospermum latifolium (N)
 * Lithospermum officinale (I)
 * Lobelia cardinalis (N)
 * Lobelia inflata (N)
 * Lobelia kalmii (N)
 * Lobelia puberula var. simulans (N)
 * Lobelia siphilitica var. siphilitica (N)
 * Lobelia spicata var. campanulata (N)
 * Lobelia spicata var. leptostachys (N)
 * Lobelia spicata var. spicata (N)
 * Lobularia maritima (I)
 * Lorinseria areolata (N)
 * Lolium perenne ssp. multiflorum (I)
 * Lolium perenne ssp. perenne (I)
 * Lolium temulentum ssp. temulentum (I)
 * Lonicera × bella (I)
 * Lonicera canadensis (N)
 * Lonicera dioica (N)
 * Lonicera flava (N)
 * Lonicera fragrantissima (I)
 * Lonicera japonica (I)
 * Lonicera × minutiflora (I)
 * Lonicera morrowii (I)
 * Lonicera maackii (I)
 * Lonicera oblongifolia (N)
 * Lonicera reticulata (N)
 * Lonicera ruprechtiana (I)
 * Lonicera × salicifolia (I)
 * Lonicera sempervirens (N)
 * Lonicera tatarica (I)
 * Lonicera villosa var. tonsa (N)
 * Lonicera × xylosteoides (I)
 * Lonicera xylosteum (I)
 * Lotus corniculatus var. corniculatus (I)
 * Lotus glaber (I)
 * Ludwigia alternifolia (N)
 * Ludwigia decurrens (N)
 * Ludwigia leptocarpa (N)
 * Ludwigia palustris (N)
 * Ludwigia peploides (I)
 * Ludwigia peploides ssp. glabrescens (N)
 * Ludwigia polycarpa (N)
 * Lunaria annua (I)
 * Lupinus perennis ssp. perennis var. occidentalis (N)
 * Lupinus perennis ssp. perennis var. perennis (N)
 * Lupinus perennis ssp. perennis (N)
 * Luzula acuminata ssp. acuminata (N)
 * Luzula acuminata ssp. carolinae (N)
 * Luzula bulbosa (N)
 * Luzula echinata (N)
 * Luzula multiflora ssp. multiflora var. multiflora (N)
 * Luzula multiflora ssp. multiflora (N)
 * Lychnis coronaria (I)
 * Lychnis flos-cuculi (I)
 * Lychnis viscaria (I)
 * Lycium barbarum (I)
 * Lycium chinense (I)
 * Lycopodiella inundata (N)
 * Lycopodiella margueritiae (N)
 * Lycopodiella subappressa (N)
 * Lycopodium clavatum (N)
 * Lycopodium dendroideum (N)
 * Lycopodium digitatum (N)
 * Lycopodium × habereri (N)
 * Lycopodium hickeyi (N)
 * Lycopodium lagopus (N)
 * Lycopodium obscurum (N)
 * Lycopodium tristachyum (N)
 * Lycopus americanus (N)
 * Lycopus asper (N)
 * Lycopus europaeus (I)
 * Lycopus rubellus (N)
 * Lycopus × sherardii (N)
 * Lycopus uniflorus var. uniflorus (N)
 * Lycopus virginicus (N)
 * Lycoris squamigera (I)
 * Lygodium palmatum (N)
 * Lyonia ligustrina var. ligustrina (N)
 * Lysimachia ciliata (N)
 * Lysimachia lanceolata (N)
 * Lysimachia nummularia (I)
 * Lysimachia × producta (N)
 * Lysimachia punctata (I)
 * Lysimachia quadriflora (N)
 * Lysimachia quadrifolia (N)
 * Lysimachia terrestris (N)
 * Lysimachia thyrsiflora (N)
 * Lysimachia vulgaris (I)
 * Lythrum alatum var. alatum (N)
 * Lythrum hyssopifolia (I)
 * Lythrum portula (I)
 * Lythrum salicaria (I)

M

 * Macleaya cordata (I)
 * Maclura pomifera (N)
 * Magnolia acuminata (N)
 * Magnolia fraseri (N)
 * Magnolia macrophylla (N)
 * Magnolia × soulangeana (I)
 * Magnolia stellata (I)
 * Magnolia tripetala (N)
 * Mahonia aquifolium (N)
 * Maianthemum canadense (N)
 * Maianthemum racemosum ssp. racemosum (N)
 * Maianthemum stellatum (N)
 * Maianthemum trifolium (N)
 * Malaxis unifolia (N)
 * Malus angustifolia var. angustifolia (N)
 * Malus baccata (I)
 * Malus coronaria (N)
 * Malus floribunda (I)
 * Malus ioensis var. ioensis (N)
 * Malus × platycarpa (N)
 * Malus pumila (I)
 * Malus toringo (I)
 * Malus zumi (I)
 * Malva alcea (I)
 * Malva moschata (I)
 * Malva neglecta (I)
 * Malva pusilla (I)
 * Malva sylvestris (I)
 * Malva verticillata (I)
 * Manfreda virginica (N)
 * Marrubium vulgare (I)
 * Marsilea quadrifolia (I)
 * Marsilea quadrifolia (N)
 * Matelea obliqua (N)
 * Matricaria discoidea (I)
 * Matricaria recutita (I)
 * Matteuccia struthiopteris (N)
 * Mazus pumilus (I)
 * Medeola virginiana (N)
 * Medicago lupulina (I)
 * Medicago polymorpha (I)
 * Medicago sativa ssp. falcata (I)
 * Medicago sativa ssp. sativa (I)
 * Meehania cordata (N)
 * Melampyrum lineare var. latifolium (N)
 * Melampyrum lineare var. lineare (N)
 * Melica nitens (N)
 * Melilotus altissimus (I)
 * Melilotus officinalis (I)
 * Melissa officinalis (I)
 * Menispermum canadense (N)
 * Mentha aquatica (I)
 * Mentha arvensis (N)
 * Mentha × gracilis (I)
 * Mentha × piperita (N)
 * Mentha × rotundifolia (I)
 * Mentha spicata (I)
 * Mentha suaveolens (I)
 * Mentha × villosa (I)
 * Menyanthes trifoliata (N)
 * Mercurialis annua (I)
 * Mertensia virginica (N)
 * Microstegium vimineum (I)
 * Microthlaspi perfoliatum (I)
 * Mikania scandens (N)
 * Milium effusum var. cisatlanticum (N)
 * Mimulus alatus (N)
 * Mimulus ringens var. ringens (N)
 * Minuartia michauxii var. michauxii (N)
 * Minuartia patula (N)
 * Mirabilis albida (N)
 * Mirabilis hirsuta (N)
 * Mirabilis jalapa (I)
 * Mirabilis nyctaginea (N)
 * Miscanthus sinensis (I)
 * Misopates orontium (I)
 * Mitchella repens (N)
 * Mitella diphylla (N)
 * Moehringia lateriflora (N)
 * Moehringia trinervia (I)
 * Mollugo verticillata (N)
 * Monarda clinopodia (N)
 * Monarda didyma (N)
 * Monarda fistulosa ssp. fistulosa var. fistulosa (N)
 * Monarda fistulosa ssp. fistulosa var. mollis (N)
 * Monarda fistulosa ssp. fistulosa (N)
 * Monarda media (N)
 * Monarda punctata ssp. punctata var. villicaulis (N)
 * Monarda punctata ssp. punctata (N)
 * Moneses uniflora (N)
 * Monolepis nuttalliana (N)
 * Monotropa hypopithys (N)
 * Monotropa uniflora (N)
 * Morella pensylvanica (N)
 * Morus alba (I)
 * Morus nigra (I)
 * Morus rubra var. rubra (N)
 * Muhlenbergia asperifolia (N)
 * Muhlenbergia capillaris (N)
 * Muhlenbergia × curtisetosa (N)
 * Muhlenbergia cuspidata (N)
 * Muhlenbergia frondosa (N)
 * Muhlenbergia glomerata (N)
 * Muhlenbergia mexicana (N)
 * Muhlenbergia schreberi (N)
 * Muhlenbergia sobolifera (N)
 * Muhlenbergia sylvatica (N)
 * Muhlenbergia tenuiflora (N)
 * Muscari armeniacum (I)
 * Muscari botryoides (I)
 * Muscari comosum (I)
 * Muscari neglectum (I)
 * Myagrum perfoliatum (I)
 * Myosotis arvensis (I)
 * Myosotis discolor (I)
 * Myosotis laxa (N)
 * Myosotis macrosperma (N)
 * Myosotis scorpioides (I)
 * Myosotis stricta (I)
 * Myosotis sylvatica (I)
 * Myosotis verna (N)
 * Myosoton aquaticum (I)
 * Myosurus minimus (N)
 * Myriophyllum aquaticum (I)
 * Myriophyllum heterophyllum (N)
 * Myriophyllum humile (N)
 * Myriophyllum pinnatum (N)
 * Myriophyllum sibiricum (N)
 * Myriophyllum spicatum (I)
 * Myriophyllum verticillatum (N)

N

 * Najas flexilis (N)
 * Najas gracillima (N)
 * Najas guadalupensis ssp. guadalupensis (N)
 * Najas marina (N)
 * Najas minor (I)
 * Napaea dioica (N)
 * Narcissus × incomparabilis (I)
 * Narcissus jonquilla (I)
 * Narcissus × medioluteus (I)
 * Narcissus poeticus (I)
 * Narcissus pseudonarcissus (I)
 * Nasturtium officinale (I)
 * Navarretia intertexta ssp. propinqua (N)
 * Nelumbo lutea (N)
 * Nelumbo nucifera (I)
 * Neobeckia aquatica (N)
 * Neottia cordata var. cordata (N)
 * Nepeta cataria (I)
 * Neslia paniculata (I)
 * Nicandra physalodes (I)
 * Nicotiana alata (I)
 * Nicotiana glauca (I)
 * Nicotiana rustica (I)
 * Nicotiana tabacum (I)
 * Nigella damascena (I)
 * Nothoscordum bivalve (N)
 * Nuphar lutea ssp. advena (N)
 * Nuphar lutea ssp. variegata (N)
 * Nuttallanthus canadensis (N)
 * Nymphaea odorata ssp. odorata (N)
 * Nymphaea odorata ssp. tuberosa (N)
 * Nymphoides peltata (I)
 * Nyssa sylvatica (N)

O

 * Obolaria virginica (N)
 * Oclemena acuminata (N)
 * Oenanthe aquatica (I)
 * Oenothera biennis (N)
 * Oenothera clelandii (N)
 * Oenothera fruticosa ssp. fruticosa (N)
 * Oenothera fruticosa ssp. glauca (N)
 * Oenothera laciniata (N)
 * Oenothera nutans (N)
 * Oenothera oakesiana (N)
 * Oenothera parviflora (N)
 * Oenothera perennis (N)
 * Oenothera pilosella ssp. pilosella (N)
 * Oenothera speciosa (N)
 * Oenothera triloba (N)
 * Oenothera villosa ssp. villosa (N)
 * Oligoneuron album (N)
 * Oligoneuron ohioense (N)
 * Oligoneuron riddellii (N)
 * Oligoneuron rigidum var. glabratum (N)
 * Oligoneuron rigidum var. rigidum (N)
 * Onoclea sensibilis (N)
 * Onopordum acanthium (I)
 * Onosmodium bejariense var. hispidissimum (N)
 * Ophioglossum engelmannii (N)
 * Ophioglossum pusillum (N)
 * Ophioglossum vulgatum (N)
 * Opuntia humifusa (N)
 * Opuntia macrorhiza var. macrorhiza (N)
 * Orbexilum onobrychis (N)
 * Orbexilum pedunculatum var. pedunculatum (N)
 * Origanum vulgare (I)
 * Ornithogalum nutans (I)
 * Ornithogalum umbellatum (I)
 * Orobanche ludoviciana ssp. ludoviciana (N)
 * Orobanche uniflora (N)
 * Orthilia secunda (N)
 * Oryzopsis asperifolia (N)
 * Osmorhiza claytonii (N)
 * Osmorhiza longistylis (N)
 * Osmunda cinnamomea var. cinnamomea (N)
 * Osmunda claytoniana (N)
 * Osmunda regalis var. spectabilis (N)
 * Ostrya virginiana var. virginiana (N)
 * Oxalis corniculata (N)
 * Oxalis dillenii (N)
 * Oxalis grandis (N)
 * Oxalis montana (N)
 * Oxalis stricta (N)
 * Oxalis violacea (N)
 * Oxydendrum arboreum (N)
 * Oxypolis rigidior (N)

P

 * Pachysandra terminalis (I)
 * Packera anonyma (N)
 * Packera aurea (N)
 * Packera glabella (N)
 * Packera obovata (N)
 * Packera paupercula (N)
 * Packera plattensis (N)
 * Panax quinquefolius (N)
 * Panax trifolius (N)
 * Panicum anceps (N)
 * Panicum capillare (N)
 * Panicum dichotomiflorum var. dichotomiflorum (N)
 * Panicum flexile (N)
 * Panicum gattingeri (N)
 * Panicum miliaceum ssp. miliaceum (I)
 * Panicum philadelphicum (N)
 * Panicum rigidulum var. elongatum (N)
 * Panicum rigidulum var. pubescens (N)
 * Panicum rigidulum var. rigidulum (N)
 * Panicum verrucosum (N)
 * Panicum virgatum var. virgatum (N)
 * Papaver argemone (I)
 * Papaver dubium (I)
 * Papaver rhoeas (I)
 * Papaver somniferum (I)
 * Parietaria pensylvanica (N)
 * Parnassia glauca (N)
 * Paronychia canadensis (N)
 * Paronychia fastigiata var. fastigiata (N)
 * Parthenium hysterophorus (I)
 * Parthenium integrifolium var. integrifolium (N)
 * Parthenocissus quinquefolia (N)
 * Parthenocissus tricuspidata (I)
 * Parthenocissus vitacea (N)
 * Pascopyrum smithii (N)
 * Paspalum floridanum (N)
 * Paspalum fluitans (N)
 * Paspalum laeve (N)
 * Paspalum pubiflorum (N)
 * Paspalum setaceum (N)
 * Passiflora incarnata (N)
 * Passiflora lutea (N)
 * Pastinaca sativa (I)
 * Paulownia tomentosa (I)
 * Paxistima canbyi (N)
 * Pedicularis canadensis ssp. canadensis (N)
 * Pedicularis lanceolata (N)
 * Pellaea atropurpurea (N)
 * Pellaea glabella ssp. glabella (N)
 * Peltandra virginica (N)
 * Pennisetum glaucum (I)
 * Penstemon alluviorum (N)
 * Penstemon calycosus (N)
 * Penstemon canescens (N)
 * Penstemon cobaea (N)
 * Penstemon digitalis (N)
 * Penstemon grandiflorus (N)
 * Penstemon hirsutus (N)
 * Penstemon laevigatus (N)
 * Penstemon pallidus (N)
 * Penstemon tubiflorus var. tubiflorus (N)
 * Penthorum sedoides (N)
 * Perideridia americana (N)
 * Perilla frutescens var. frutescens (I)
 * Petasites hybridus (I)
 * Petrorhagia prolifera (I)
 * Petrorhagia saxifraga (I)
 * Petroselinum crispum (I)
 * Petunia × atkinsiana (I)
 * Petunia axillaris (I)
 * Phacelia bipinnatifida (N)
 * Phacelia dubia var. dubia (N)
 * Phacelia purshii (N)
 * Phacelia ranunculacea (N)
 * Phalaris arundinacea (N)
 * Phalaris canariensis (I)
 * Phalaris caroliniana (N)
 * Phaseolus coccineus (I)
 * Phaseolus polystachios var. polystachios (N)
 * Phaseolus vulgaris (I)
 * Phegopteris connectilis (N)
 * Phegopteris hexagonoptera (N)
 * Phellodendron amurense (I)
 * Philadelphus coronarius (I)
 * Philadelphus inodorus (N)
 * Philadelphus pubescens var. pubescens (N)
 * Philadelphus tomentosus (I)
 * Phleum pratense (I)
 * Phlox divaricata ssp. divaricata (N)
 * Phlox glaberrima ssp. triflora (N)
 * Phlox latifolia (N)
 * Phlox maculata ssp. maculata (N)
 * Phlox maculata ssp. pyramidalis (N)
 * Phlox paniculata (N)
 * Phlox pilosa ssp. pilosa (N)
 * Phlox stolonifera (N)
 * Phlox subulata ssp. brittonii (N)
 * Phlox subulata ssp. subulata (N)
 * Phoradendron leucarpum (N)
 * Photinia floribunda (N)
 * Photinia melanocarpa (N)
 * Phragmites australis (N)
 * Phryma leptostachya (N)
 * Phyla lanceolata (N)
 * Phyllanthus caroliniensis ssp. caroliniensis (N)
 * Physalis alkekengi (I)
 * Physalis grisea (N)
 * Physalis heterophylla var. heterophylla (N)
 * Physalis hispida (N)
 * Physalis longifolia var. longifolia (N)
 * Physalis longifolia var. subglabrata (N)
 * Physalis philadelphica var. immaculata (I)
 * Physalis pubescens var. integrifolia (N)
 * Physalis pubescens var. pubescens (N)
 * Physalis virginiana var. virginiana (N)
 * Physematium obtusum ssp. obtusa (N)
 * Physocarpus opulifolius var. intermedius (N)
 * Physocarpus opulifolius var. opulifolius (N)
 * Physostegia virginiana ssp. praemorsa (N)
 * Physostegia virginiana ssp. virginiana (N)
 * Phytolacca americana var. americana (N)
 * Picea abies (I)
 * Picris echioides (I)
 * Picris hieracioides (N)
 * Picris hieracioides ssp. hieracioides (I)
 * Pilea fontana (N)
 * Pilea pumila var. pumila (N)
 * Pimpinella saxifraga ssp. saxifraga (I)
 * Pinellia ternata (I)
 * Pinus banksiana (N)
 * Pinus echinata (N)
 * Pinus nigra (I)
 * Pinus rigida (N)
 * Pinus strobus (N)
 * Pinus sylvestris (I)
 * Pinus virginiana (N)
 * Piptatherum racemosum (N)
 * Piptochaetium avenaceum (N)
 * Pistia stratiotes (N)
 * Pityopsis graminifolia var. latifolia (N)
 * Plantago aristata (N)
 * Plantago cordata (N)
 * Plantago lanceolata (I)
 * Plantago major (I)
 * Plantago patagonica (N)
 * Plantago psyllium (I)
 * Plantago rugelii var. rugelii (N)
 * Plantago virginica (N)
 * Platanthera × andrewsii (N)
 * Platanthera aquilonis (N)
 * Platanthera blephariglottis var. blephariglottis (N)
 * Platanthera ciliaris (N)
 * Platanthera clavellata (N)
 * Platanthera flava var. herbiola (N)
 * Platanthera grandiflora (N)
 * Platanthera hookeri (N)
 * Platanthera lacera (N)
 * Platanthera leucophaea (N)
 * Platanthera orbiculata (N)
 * Platanthera peramoena (N)
 * Platanthera psycodes (N)
 * Platanus occidentalis (N)
 * Pleopeltis polypodioides ssp. michauxiana (N)
 * Pluchea camphorata (N)
 * Poa alsodes (N)
 * Poa annua (I)
 * Poa arida (N)
 * Poa bulbosa (I)
 * Poa chapmaniana (N)
 * Poa compressa (I)
 * Poa cuspidata (N)
 * Poa nemoralis (N)
 * Poa nemoralis ssp. nemoralis (I)
 * Poa paludigena (N)
 * Poa palustris (N)
 * Poa pratensis (I)
 * Poa pratensis ssp. pratensis (N)
 * Poa saltuensis (N)
 * Poa sylvestris (N)
 * Poa trivialis (I)
 * Poa wolfii (N)
 * Podophyllum peltatum (N)
 * Podostemum ceratophyllum (N)
 * Pogonia ophioglossoides (N)
 * Polanisia dodecandra ssp. dodecandra (N)
 * Polanisia dodecandra ssp. trachysperma (N)
 * Polanisia jamesii (N)
 * Polemonium caeruleum (I)
 * Polemonium reptans var. reptans (N)
 * Polemonium reptans var. villosum (N)
 * Polygala ambigua (N)
 * Polygala cruciata var. aquilonia (N)
 * Polygala curtissii (N)
 * Polygala incarnata (N)
 * Polygala paucifolia (N)
 * Polygala polygama (N)
 * Polygala sanguinea (N)
 * Polygala senega (N)
 * Polygala verticillata var. isocycla (N)
 * Polygala verticillata var. verticillata (N)
 * Polygonatum biflorum var. commutatum (N)
 * Polygonatum pubescens (N)
 * Polygonum achoreum (N)
 * Polygonum amphibium var. emersum (N)
 * Polygonum amphibium var. stipulaceum (N)
 * Polygonum arenastrum (I)
 * Polygonum arifolium (N)
 * Polygonum aviculare (I)
 * Polygonum buxiforme (N)
 * Polygonum careyi (N)
 * Polygonum cespitosum var. longisetum (I)
 * Polygonum ciliinode (N)
 * Polygonum convolvulus var. convolvulus (I)
 * Polygonum erectum (N)
 * Polygonum fowleri ssp. fowleri (N)
 * Polygonum hydropiper (I)
 * Polygonum hydropiperoides (N)
 * Polygonum lapathifolium (N)
 * Polygonum orientale (I)
 * Polygonum pensylvanicum (N)
 * Polygonum perfoliatum (I)
 * Polygonum persicaria (I)
 * Polygonum punctatum var. confertiflorum (N)
 * Polygonum punctatum var. punctatum (N)
 * Polygonum ramosissimum var. ramosissimum (N)
 * Polygonum robustius (N)
 * Polygonum sachalinense (I)
 * Polygonum sagittatum (N)
 * Polygonum scandens var. cristatum (N)
 * Polygonum scandens var. dumetorum (N)
 * Polygonum scandens var. scandens (N)
 * Polygonum scandens var. dumetorum (I)
 * Polygonum setaceum (N)
 * Polygonum tenue (N)
 * Polygonum virginianum (N)
 * Polymnia canadensis (N)
 * Polypodium appalachianum (N)
 * Polypodium virginianum (N)
 * Polystichum acrostichoides var. acrostichoides (N)
 * Pontederia cordata (N)
 * Populus alba (I)
 * Populus balsamifera ssp. balsamifera (N)
 * Populus × canadensis (N)
 * Populus × canescens (I)
 * Populus deltoides ssp. deltoides (N)
 * Populus deltoides ssp. monilifera (N)
 * Populus grandidentata (N)
 * Populus heterophylla (N)
 * Populus × jackii (N)
 * Populus nigra (I)
 * Populus × smithii (N)
 * Populus tremuloides (N)
 * Portulaca grandiflora (I)
 * Portulaca oleracea (I)
 * Portulaca oleracea (N)
 * Potamogeton amplifolius (N)
 * Potamogeton compressus (N)
 * Potamogeton crispus (I)
 * Potamogeton diversifolius (N)
 * Potamogeton epihydrus (N)
 * Potamogeton foliosus ssp. foliosus (N)
 * Potamogeton friesii (N)
 * Potamogeton gramineus (N)
 * Potamogeton × hagstroemii (N)
 * Potamogeton hillii (N)
 * Potamogeton illinoensis (N)
 * Potamogeton natans (N)
 * Potamogeton nodosus (N)
 * Potamogeton perfoliatus (N)
 * Potamogeton praelongus (N)
 * Potamogeton pulcher (N)
 * Potamogeton pusillus ssp. pusillus (N)
 * Potamogeton pusillus ssp. tenuissimus (N)
 * Potamogeton × rectifolius (N)
 * Potamogeton richardsonii (N)
 * Potamogeton robbinsii (N)
 * Potamogeton spirillus (N)
 * Potamogeton strictifolius (N)
 * Potamogeton tennesseensis (N)
 * Potamogeton vaseyi (N)
 * Potentilla argentea var. argentea (I)
 * Potentilla arguta ssp. arguta (N)
 * Potentilla canadensis var. canadensis (N)
 * Potentilla canadensis var. villosissima (N)
 * Potentilla inclinata (I)
 * Potentilla intermedia (I)
 * Potentilla norvegica ssp. monspeliensis (N)
 * Potentilla paradoxa (N)
 * Potentilla pensylvanica var. pensylvanica (N)
 * Potentilla recta (I)
 * Potentilla reptans (I)
 * Potentilla simplex (N)
 * Prenanthes alba (N)
 * Prenanthes altissima (N)
 * Prenanthes aspera (N)
 * Prenanthes crepidinea (N)
 * Prenanthes racemosa var. racemosa (N)
 * Prenanthes serpentaria (N)
 * Prenanthes trifoliolata (N)
 * Proboscidea louisianica ssp. louisianica (N)
 * Prosartes lanuginosa (N)
 * Prosartes maculata (N)
 * Proserpinaca palustris var. amblyogona (N)
 * Proserpinaca palustris var. crebra (N)
 * Prunella laciniata (I)
 * Prunella vulgaris ssp. lanceolata (N)
 * Prunus americana (N)
 * Prunus avium (I)
 * Prunus cerasifera (I)
 * Prunus cerasus (I)
 * Prunus domestica var. domestica (I)
 * Prunus hortulana (N)
 * Prunus mahaleb (I)
 * Prunus mexicana (N)
 * Prunus munsoniana (N)
 * Prunus nigra (N)
 * Prunus pensylvanica var. pensylvanica (N)
 * Prunus persica var. persica (I)
 * Prunus pumila var. pumila (N)
 * Prunus serotina var. serotina (N)
 * Prunus subhirtella (I)
 * Prunus susquehanae (N) (here considered a synonym of P. pumila)
 * Prunus tomentosa (I)
 * Prunus virginiana var. virginiana (N)
 * Psammophiliella muralis (syn. Gypsophila muralis) (I)
 * Pseudognaphalium macounii (N)
 * Pseudognaphalium obtusifolium ssp. obtusifolium (N)
 * Pseudolysimachion longifolium (I)
 * Ptelea trifoliata ssp. trifoliata var. trifoliata (N)
 * Ptelea trifoliata ssp. trifoliata (N)
 * Pteridium aquilinum var. latiusculum (N)
 * Pteridium aquilinum var. pseudocaudatum (N)
 * Puccinellia distans (N)
 * Puccinellia distans ssp. distans (I)
 * Pueraria montana var. lobata (I)
 * Pycnanthemum incanum var. incanum (N)
 * Pycnanthemum incanum var. puberulum (N)
 * Pycnanthemum muticum (N)
 * Pycnanthemum pycnanthemoides var. pycnanthemoides (N)
 * Pycnanthemum tenuifolium (N)
 * Pycnanthemum verticillatum var. pilosum (N)
 * Pycnanthemum verticillatum var. verticillatum (N)
 * Pycnanthemum virginianum (N)
 * Pyracantha coccinea (I)
 * Pyracantha coccinea (N)
 * Pyrola americana (N)
 * Pyrola asarifolia ssp. asarifolia (N)
 * Pyrola chlorantha (N)
 * Pyrola elliptica (N)
 * Pyrus calleryana (I)
 * Pyrus communis (I)

Q

 * Quercus alba (N)
 * Quercus × bebbiana (N)
 * Quercus bicolor (N)
 * Quercus × bushii (N)
 * Quercus coccinea var. coccinea (N)
 * Quercus coccinea var. tuberculata (N)
 * Quercus × deamii (N)
 * Quercus ellipsoidalis (N)
 * Quercus × exacta (N)
 * Quercus falcata (N)
 * Quercus × fontana (N)
 * Quercus × hawkinsiae (N)
 * Quercus imbricaria (N)
 * Quercus × jackiana (N)
 * Quercus × leana (N)
 * Quercus macrocarpa var. macrocarpa (N)
 * Quercus marilandica var. marilandica (N)
 * Quercus muehlenbergii (N)
 * Quercus × mutabilis (N)
 * Quercus × palaeolithicola (N)
 * Quercus palustris (N)
 * Quercus prinus (N)
 * Quercus robur (I)
 * Quercus rubra var. ambigua (N)
 * Quercus rubra var. rubra (N)
 * Quercus × runcinata (N)
 * Quercus × saulii (N)
 * Quercus × schuettei (N)
 * Quercus shumardii var. schneckii (N)
 * Quercus shumardii var. shumardii (N)
 * Quercus stellata (N)
 * Quercus × tridentata (N)
 * Quercus velutina (N)

R

 * Ranunculus abortivus (N)
 * Ranunculus acris var. acris (N)
 * Ranunculus acris var. acris (I)
 * Ranunculus allegheniensis (N)
 * Ranunculus ambigens (N)
 * Ranunculus arvensis (I)
 * Ranunculus bulbosus (I)
 * Ranunculus fascicularis (N)
 * Ranunculus ficaria var. bulbifera (I)
 * Ranunculus flabellaris (N)
 * Ranunculus hispidus var. caricetorum (N)
 * Ranunculus hispidus var. hispidus (N)
 * Ranunculus hispidus var. nitidus (N)
 * Ranunculus longirostris (N)
 * Ranunculus micranthus (N)
 * Ranunculus parviflorus (I)
 * Ranunculus pensylvanicus (N)
 * Ranunculus pusillus var. pusillus (N)
 * Ranunculus recurvatus var. recurvatus (N)
 * Ranunculus repens (I)
 * Ranunculus sceleratus var. sceleratus (N)
 * Raphanus raphanistrum (I)
 * Raphanus sativus (I)
 * Ratibida columnifera (N)
 * Ratibida pinnata (N)
 * Reseda alba (I)
 * Reseda lutea (I)
 * Reseda luteola (I)
 * Reynoutria japonica (syn. Polygonum cuspidatum) (I)
 * Rhamnus alnifolia (N)
 * Rhamnus cathartica (I)
 * Rhamnus davurica ssp. davurica (I)
 * Rhamnus lanceolata ssp. glabrata (N)
 * Rhamnus lanceolata ssp. lanceolata (N)
 * Rhamnus utilis (I)
 * Rheum rhabarbarum (I)
 * Rhexia virginica (N)
 * Rhododendron calendulaceum (N)
 * Rhododendron maximum (N)
 * Rhododendron periclymenoides (N)
 * Rhododendron prinophyllum (N)
 * Rhodotypos scandens (I)
 * Rhus aromatica var. arenaria (N)
 * Rhus aromatica var. aromatica (N)
 * Rhus copallinum var. latifolia (N)
 * Rhus glabra (N)
 * Rhus pulvinata (N)
 * Rhus typhina (N)
 * Rhynchospora alba (N)
 * Rhynchospora capillacea (N)
 * Rhynchospora capitellata (N)
 * Rhynchospora recognita (N)
 * Ribes americanum (N)
 * Ribes aureum var. villosum (N)
 * Ribes cynosbati (N)
 * Ribes glandulosum (N)
 * Ribes hirtellum (N)
 * Ribes missouriense (N)
 * Ribes nigrum (I)
 * Ribes oxyacanthoides ssp. oxyacanthoides (N)
 * Ribes rotundifolium (N)
 * Ribes rubrum (I)
 * Ribes triste (N)
 * Ribes uva-crispa var. sativum (I)
 * Ricinus communis (I)
 * Robinia × ambigua (N)
 * Robinia hispida var. fertilis (N)
 * Robinia hispida var. hispida (N)
 * Robinia pseudoacacia (N)
 * Robinia viscosa var. viscosa (N)
 * Rorippa palustris ssp. fernaldiana (N)
 * Rorippa palustris ssp. hispida (N)
 * Rorippa sessiliflora (N)
 * Rorippa sylvestris (I)
 * Rosa arkansana var. suffulta (N)
 * Rosa blanda var. blanda (N)
 * Rosa canina (I)
 * Rosa carolina var. carolina (N)
 * Rosa centifolia (I)
 * Rosa cinnamomea (I)
 * Rosa eglanteria (I)
 * Rosa gallica (I)
 * Rosa majalis (I)
 * Rosa micrantha (I)
 * Rosa multiflora (I)
 * Rosa nitida (N)
 * Rosa × palustriformis (N)
 * Rosa palustris (N)
 * Rosa pimpinellifolia (I)
 * Rosa × rudiuscula (N)
 * Rosa rugosa (I)
 * Rosa setigera var. setigera (N)
 * Rosa setigera var. tomentosa (N)
 * Rosa wichuraiana (I)
 * Rotala ramosior (N)
 * Rubus aboriginum (N)
 * Rubus allegheniensis var. allegheniensis (N)
 * Rubus allegheniensis var. gravesii (N)
 * Rubus alumnus (N)
 * Rubus argutus (N)
 * Rubus armeniacus (I)
 * Rubus baileyanus (N)
 * Rubus bellobatus (N)
 * Rubus canadensis (N)
 * Rubus deamii (N)
 * Rubus depavitus (N)
 * Rubus fecundus (N)
 * Rubus flagellaris (N)
 * Rubus frondosus (N)
 * Rubus hispidus (N)
 * Rubus idaeus ssp. strigosus (N)
 * Rubus idaeus ssp. idaeus (I)
 * Rubus invisus (N)
 * Rubus laciniatus (I)
 * Rubus laudatus (N)
 * Rubus meracus (N)
 * Rubus michiganensis (N)
 * Rubus multifer (N)
 * Rubus occidentalis (N)
 * Rubus odoratus var. odoratus (N)
 * Rubus pensilvanicus (N)
 * Rubus pergratus (N)
 * Rubus philadelphicus (N)
 * Rubus phoenicolasius (I)
 * Rubus plicatifolius (N)
 * Rubus prestonensis (N)
 * Rubus pubescens var. pubescens (N)
 * Rubus recurvans (N)
 * Rubus recurvicaulis (N)
 * Rubus roribaccus (N)
 * Rubus rosa (N)
 * Rubus setosus (N)
 * Rubus suus (N)
 * Rubus trivialis (N)
 * Rubus uvidus (N)
 * Rubus vagus (N)
 * Rudbeckia fulgida var. deamii (N)
 * Rudbeckia fulgida var. fulgida (N)
 * Rudbeckia fulgida var. speciosa (N)
 * Rudbeckia fulgida var. umbrosa (N)
 * Rudbeckia grandiflora var. grandiflora (N)
 * Rudbeckia hirta var. hirta (N)
 * Rudbeckia hirta var. pulcherrima (N)
 * Rudbeckia laciniata var. laciniata (N)
 * Rudbeckia triloba var. triloba (N)
 * Ruellia caroliniensis ssp. caroliniensis var. caroliniensis (N)
 * Ruellia caroliniensis ssp. caroliniensis (N)
 * Ruellia humilis (N)
 * Ruellia strepens (N)
 * Rumex acetosa (N)
 * Rumex acetosa ssp. acetosa (I)
 * Rumex acetosella (I)
 * Rumex × acutus (I)
 * Rumex × acutus (N)
 * Rumex altissimus (N)
 * Rumex conglomeratus (I)
 * Rumex crispus ssp. crispus (I)
 * Rumex maritimus (N)
 * Rumex obtusifolius (I)
 * Rumex orbiculatus var. borealis (N)
 * Rumex orbiculatus var. orbiculatus (N)
 * Rumex patientia (I)
 * Rumex salicifolius var. mexicanus (N)
 * Rumex verticillatus (N)
 * Ruppia cirrhosa (N)

S

 * Sabatia angularis (N)
 * Saccharum alopecuroides (N)
 * Saccharum ravennae (I)
 * Sagina decumbens ssp. decumbens (N)
 * Sagina japonica (I)
 * Sagina procumbens (I)
 * Sagina procumbens (N)
 * Sagittaria australis (N)
 * Sagittaria brevirostra (N)
 * Sagittaria calycina var. calycina (N)
 * Sagittaria cuneata (N)
 * Sagittaria graminea var. graminea (N)
 * Sagittaria latifolia (N)
 * Sagittaria platyphylla (N)
 * Sagittaria rigida (N)
 * Salicornia depressa (N)
 * Salix alba (I)
 * Salix amygdaloides (N)
 * Salix bebbiana (N)
 * Salix candida (N)
 * Salix caprea (I)
 * Salix caroliniana (N)
 * Salix cinerea (I)
 * Salix discolor (N)
 * Salix × ehrhartiana (I)
 * Salix × ehrhartiana (N)
 * Salix eriocephala (N)
 * Salix fragilis (I)
 * Salix × glatfelteri (N)
 * Salix humilis var. humilis (N)
 * Salix humilis var. tristis (N)
 * Salix interior (N)
 * Salix lucida ssp. lucida (N)
 * Salix matsudana (I)
 * Salix myricoides var. albovestita (N)
 * Salix myricoides var. myricoides (N)
 * Salix nigra (N)
 * Salix pedicellaris (N)
 * Salix × pendulina (I)
 * Salix pentandra (I)
 * Salix petiolaris (N)
 * Salix purpurea (I)
 * Salix × rubens (I)
 * Salix sericea (N)
 * Salix serissima (N)
 * Salix viminalis (I)
 * Salsola collina (I)
 * Salsola tragus (I)
 * Salvia azurea var. grandiflora (N)
 * Salvia coccinea (N)
 * Salvia farinacea (N)
 * Salvia lyrata (N)
 * Salvia officinalis (I)
 * Salvia pratensis (I)
 * Salvia reflexa (N)
 * Salvia splendens (I)
 * Salvia × superba (I)
 * Salvia × sylvestris (I)
 * Sambucus nigra (I)
 * Sambucus nigra ssp. canadensis (N)
 * Sambucus racemosa var. racemosa (N)
 * Samolus valerandi (I)
 * Samolus valerandi ssp. parviflorus (N)
 * Sanguinaria canadensis (N)
 * Sanguisorba canadensis (N)
 * Sanguisorba minor ssp. balearica (I)
 * Sanicula canadensis var. canadensis (N)
 * Sanicula canadensis var. grandis (N)
 * Sanicula marilandica (N)
 * Sanicula odorata (N)
 * Sanicula smallii (N)
 * Sanicula trifoliata (N)
 * Saponaria officinalis (I)
 * Sarracenia purpurea ssp. purpurea (N)
 * Sassafras albidum (N)
 * Satureja hortensis (I)
 * Saururus cernuus (N)
 * Saxifraga pensylvanica (N)
 * Saxifraga virginiensis var. virginiensis (N)
 * Scabiosa columbaria (I)
 * Scandix pecten-veneris (I)
 * Schedonorus phoenix (I)
 * Schedonorus pratensis (I)
 * Scheuchzeria palustris ssp. americana (N)
 * Schizachne purpurascens (N)
 * Schizachyrium littorale (N)
 * Schizachyrium scoparium var. scoparium (N)
 * Schoenoplectus acutus var. acutus (N)
 * Schoenoplectus fluviatilis (N)
 * Schoenoplectus pungens var. pungens (N)
 * Schoenoplectus purshianus (N)
 * Schoenoplectus saximontanus (N)
 * Schoenoplectus smithii (N)
 * Schoenoplectus subterminalis (N)
 * Schoenoplectus tabernaemontani (N)
 * Schoenoplectus torreyi (N)
 * Scilla siberica (I)
 * Scirpus atrovirens (N)
 * Scirpus cyperinus (N)
 * Scirpus expansus (N)
 * Scirpus georgianus (N)
 * Scirpus hattorianus (N)
 * Scirpus pedicellatus (N)
 * Scirpus pendulus (N)
 * Scirpus polyphyllus (N)
 * Scleranthus annuus (I)
 * Scleria oligantha (N)
 * Scleria pauciflora var. caroliniana (N)
 * Scleria pauciflora var. pauciflora (N)
 * Scleria triglomerata (N)
 * Scleria verticillata (N)
 * Sclerochloa dura (I)
 * Sclerochloa dura (N)
 * Scrophularia lanceolata (N)
 * Scrophularia marilandica (N)
 * Scutellaria elliptica var. elliptica (N)
 * Scutellaria elliptica var. hirsuta (N)
 * Scutellaria galericulata (N)
 * Scutellaria incana var. incana (N)
 * Scutellaria integrifolia (N)
 * Scutellaria lateriflora var. lateriflora (N)
 * Scutellaria nervosa (N)
 * Scutellaria ovata ssp. ovata (N)
 * Scutellaria parvula var. missouriensis (N)
 * Scutellaria parvula var. parvula (N)
 * Scutellaria saxatilis (N)
 * Scutellaria serrata (N)
 * Secale cereale (I)
 * Securigera varia (I)
 * Sedum acre (I)
 * Sedum album (I)
 * Sedum dendroideum (I)
 * Sedum pulchellum (N)
 * Sedum reflexum (I)
 * Sedum sarmentosum (I)
 * Sedum sexangulare (I)
 * Sedum ternatum (N)
 * Selaginella apoda (N)
 * Selaginella eclipes (N)
 * Selaginella rupestris (N)
 * Senecio sylvaticus (I)
 * Senecio vulgaris (I)
 * Senna hebecarpa (N)
 * Senna marilandica (N)
 * Sericocarpus asteroides (N)
 * Sericocarpus linifolius (N)
 * Sesamum orientale (I)
 * Setaria faberi (I)
 * Setaria italica (I)
 * Setaria parviflora (N)
 * Setaria pumila ssp. pumila (I)
 * Setaria verticillata (I)
 * Setaria viridis var. viridis (I)
 * Shepherdia canadensis (N)
 * Sherardia arvensis (I)
 * Sibara virginica (N)
 * Sicyos angulatus (N)
 * Sida hermaphrodita (N)
 * Sida spinosa (N)
 * Silene antirrhina (N)
 * Silene armeria (I)
 * Silene caroliniana ssp. pensylvanica (N)
 * Silene caroliniana ssp. wherryi (N)
 * Silene conica (I)
 * Silene csereii (I)
 * Silene dichotoma (I)
 * Silene dioica (I)
 * Silene latifolia ssp. alba (I)
 * Silene nivea (N)
 * Silene noctiflora (I)
 * Silene nutans (I)
 * Silene regia (N)
 * Silene rotundifolia (N)
 * Silene stellata (N)
 * Silene virginica var. virginica (N)
 * Silene vulgaris (I)
 * Silphium laciniatum var. laciniatum (N)
 * Silphium perfoliatum var. perfoliatum (N)
 * Silphium terebinthinaceum var. luciae-brauniae (N)
 * Silphium terebinthinaceum var. terebinthinaceum (N)
 * Silphium trifoliatum var. latifolium (N)
 * Silphium trifoliatum var. trifoliatum (N)
 * Silybum marianum (I)
 * Sinapis alba (I)
 * Sinapis arvensis ssp. arvensis (I)
 * Sisymbrium altissimum (I)
 * Sisymbrium irio (I)
 * Sisymbrium loeselii (I)
 * Sisymbrium officinale (I)
 * Sisyrinchium albidum (N)
 * Sisyrinchium angustifolium (N)
 * Sisyrinchium atlanticum (N)
 * Sisyrinchium montanum var. crebrum (N)
 * Sisyrinchium mucronatum (N)
 * Sium suave (N)
 * Smallanthus uvedalia (N)
 * Smilax ecirrhata (N)
 * Smilax glauca (N)
 * Smilax herbacea (N)
 * Smilax illinoensis (N)
 * Smilax lasioneura (N)
 * Smilax pulverulenta (N)
 * Smilax rotundifolia (N)
 * Smilax tamnoides (N)
 * Solanum carolinense var. carolinense (N)
 * Solanum dulcamara var. dulcamara (I)
 * Solanum lycopersicum var. lycopersicum (I)
 * Solanum physalifolium (I)
 * Solanum ptychanthum (N)
 * Solanum rostratum (N)
 * Solanum triflorum (N)
 * Solanum tuberosum (I)
 * Solidago altissima (N)
 * Solidago arguta var. arguta (N)
 * Solidago bicolor (N)
 * Solidago caesia (N)
 * Solidago canadensis var. canadensis (N)
 * Solidago canadensis var. gilvocanescens (N)
 * Solidago canadensis var. hargeri (N)
 * Solidago erecta (N)
 * Solidago flexicaulis (N)
 * Solidago gigantea (N)
 * Solidago hispida var. hispida (N)
 * Solidago juncea (N)
 * Solidago nemoralis var. nemoralis (N)
 * Solidago odora var. odora (N)
 * Solidago patula var. patula (N)
 * Solidago puberula var. puberula (N)
 * Solidago rugosa ssp. aspera (N)
 * Solidago rugosa ssp. rugosa var. rugosa (N)
 * Solidago rugosa ssp. rugosa var. villosa (N)
 * Solidago rugosa ssp. rugosa (N)
 * Solidago rupestris (N)
 * Solidago sempervirens var. sempervirens (N)
 * Solidago speciosa var. rigidiuscula (N)
 * Solidago speciosa var. speciosa (N)
 * Solidago sphacelata (N)
 * Solidago squarrosa (N)
 * Solidago uliginosa var. linoides (N)
 * Solidago uliginosa var. uliginosa (N)
 * Solidago ulmifolia var. ulmifolia (N)
 * Sonchus arvensis ssp. arvensis (I)
 * Sonchus arvensis ssp. uliginosus (I)
 * Sonchus asper (I)
 * Sonchus oleraceus (I)
 * Sorbaria sorbifolia (I)
 * Sorbus aucuparia (I)
 * Sorbus decora (N)
 * Sorghastrum nutans (N)
 * Sorghum bicolor ssp. bicolor (I)
 * Sorghum halepense (I)
 * Sparganium americanum (N)
 * Sparganium androcladum (N)
 * Sparganium emersum (I)
 * Sparganium emersum (N)
 * Sparganium eurycarpum (N)
 * Spartina pectinata (N)
 * Spergula arvensis (I)
 * Spergularia maritima (I)
 * Spergularia rubra (I)
 * Spergularia salina (N)
 * Spermacoce glabra (N)
 * Sphenopholis intermedia (N)
 * Sphenopholis nitida (N)
 * Sphenopholis obtusata (N)
 * Sphenopholis × pallens (N)
 * Sphenopholis pensylvanica (N)
 * Spinacia oleracea (I)
 * Spiraea alba var. alba (N)
 * Spiraea alba var. latifolia (N)
 * Spiraea japonica var. fortunei (I)
 * Spiraea prunifolia (I)
 * Spiraea tomentosa (N)
 * Spiraea × vanhouttei (I)
 * Spiraea virginiana (N)
 * Spiranthes cernua (N)
 * Spiranthes lacera var. gracilis (N)
 * Spiranthes lacera var. lacera (N)
 * Spiranthes lucida (N)
 * Spiranthes magnicamporum (N)
 * Spiranthes ochroleuca (N)
 * Spiranthes ovalis var. erostellata (N)
 * Spiranthes romanzoffiana (N)
 * Spiranthes tuberosa (N)
 * Spiranthes vernalis (N)
 * Spirodela polyrrhiza (N)
 * Sporobolus compositus var. compositus (N)
 * Sporobolus cryptandrus (N)
 * Sporobolus heterolepis (N)
 * Sporobolus neglectus (N)
 * Sporobolus vaginiflorus var. ozarkanus (N)
 * Sporobolus vaginiflorus var. vaginiflorus (N)
 * Stachys aspera (N)
 * Stachys cordata (N)
 * Stachys germanica (I)
 * Stachys palustris (N)
 * Stachys pilosa var. arenicola (N)
 * Stachys sylvatica (I)
 * Stachys tenuifolia (N)
 * Staphylea trifolia (N)
 * Stellaria alsine (N)
 * Stellaria corei (N)
 * Stellaria graminea (I)
 * Stellaria holostea (I)
 * Stellaria longifolia var. longifolia (N)
 * Stellaria media ssp. media (I)
 * Stellaria media ssp. pallida (I)
 * Stellaria pubera (N)
 * Stenanthium gramineum var. gramineum (N)
 * Stenanthium gramineum var. robustum (N)
 * Stenaria nigricans var. nigricans (N)
 * Stenosiphon linifolius (N)
 * Streptopus lanceolatus var. lanceolatus (N)
 * Streptopus lanceolatus var. roseus (N)
 * Strophostyles helvola (N)
 * Strophostyles leiosperma (N)
 * Strophostyles umbellata (N)
 * Stuckenia filiformis ssp. alpina (N)
 * Stuckenia pectinata (N)
 * Stuckenia vaginata (N)
 * Stylophorum diphyllum (N)
 * Stylosanthes biflora (N)
 * Styphnolobium japonicum (I)
 * Styrax americanus (N)
 * Styrax grandifolius (N)
 * Suaeda calceoliformis (N)
 * Sullivantia sullivantii (N)
 * Symphoricarpos albus var. albus (N)
 * Symphoricarpos albus var. laevigatus (N)
 * Symphoricarpos occidentalis (N)
 * Symphoricarpos orbiculatus (N)
 * Symphyotrichum boreale (N)
 * Symphyotrichum ciliatum (N)
 * Symphyotrichum cordifolium (N)
 * Symphyotrichum drummondii var. drummondii (N)
 * Symphyotrichum dumosum var. strictior (N)
 * Symphyotrichum ericoides var. ericoides (N)
 * Symphyotrichum laeve var. laeve (N)
 * Symphyotrichum lanceolatum ssp. lanceolatum var. hirsuticaule (N)
 * Symphyotrichum lanceolatum ssp. lanceolatum var. interior (N)
 * Symphyotrichum lanceolatum ssp. lanceolatum var. lanceolatum (N)
 * Symphyotrichum lanceolatum ssp. lanceolatum var. latifolium (N)
 * Symphyotrichum lanceolatum ssp. lanceolatum (N)
 * Symphyotrichum lateriflorum var. lateriflorum (N)
 * Symphyotrichum lowrieanum (N)
 * Symphyotrichum novae-angliae (N)
 * Symphyotrichum oblongifolium (N)
 * Symphyotrichum ontarionis (N)
 * Symphyotrichum oolentangiense var. oolentangiense (N)
 * Symphyotrichum patens var. patens (N)
 * Symphyotrichum phlogifolium (N)
 * Symphyotrichum pilosum var. pilosum (N)
 * Symphyotrichum pilosum var. pringlei (N)
 * Symphyotrichum praealtum var. praealtum (N)
 * Symphyotrichum prenanthoides (N)
 * Symphyotrichum puniceum var. puniceum (N)
 * Symphyotrichum racemosum (N)
 * Symphyotrichum sericeum (N)
 * Symphyotrichum shortii (N)
 * Symphyotrichum subulatum (N)
 * Symphyotrichum undulatum (N)
 * Symphyotrichum urophyllum (N)
 * Symphytum asperum (I)
 * Symphytum officinale (I)
 * Symplocarpus foetidus (N)
 * Synandra hispidula (N)
 * Syringa vulgaris (I)

T

 * Taenidia integerrima (N)
 * Tagetes erecta (I)
 * Tagetes patula (I)
 * Tamarix chinensis (I)
 * Tanacetum balsamita (I)
 * Tanacetum coccineum (I)
 * Tanacetum parthenium (I)
 * Tanacetum vulgare (I)
 * Taraxacum laevigatum (I)
 * Taraxacum officinale (N)
 * Taraxacum officinale ssp. officinale (I)
 * Taxodium distichum (N)
 * Taxus canadensis (N)
 * Taxus cuspidata (I)
 * Tephrosia virginiana (N)
 * Tetradium daniellii (I)
 * Tetragonia tetragonioides (I)
 * Tetraneuris herbacea (N)
 * Teucrium canadense var. canadense (N)
 * Teucrium canadense var. occidentale (N)
 * Thalictrum dasycarpum (N)
 * Thalictrum dioicum (N)
 * Thalictrum pubescens (N)
 * Thalictrum revolutum (N)
 * Thalictrum thalictroides (N)
 * Thaspium barbinode (N)
 * Thaspium trifoliatum var. aureum (N)
 * Thaspium trifoliatum var. trifoliatum (N)
 * Thelypteris noveboracensis (N)
 * Thelypteris palustris var. pubescens (N)
 * Thlaspi alliaceum (I)
 * Thlaspi arvense (I)
 * Thuja occidentalis (N)
 * Thymelaea passerina (I)
 * Thymelaea passerina (N)
 * Thymus praecox ssp. arcticus (I)
 * Tiarella cordifolia var. cordifolia (N)
 * Tilia americana var. americana (N)
 * Tilia americana var. heterophylla (N)
 * Tilia × europaea (I)
 * Tipularia discolor (N)
 * Torilis arvensis ssp. arvensis (N)
 * Torilis arvensis ssp. arvensis (I)
 * Torilis japonica (I)
 * Torreyochloa pallida var. pallida (N)
 * Toxicodendron radicans ssp. negundo (N)
 * Toxicodendron rydbergii (N)
 * Toxicodendron vernix (N)
 * Tradescantia ohiensis (N)
 * Tradescantia subaspera var. subaspera (N)
 * Tradescantia virginiana (N)
 * Tragopogon dubius (I)
 * Tragopogon lamottei (I)
 * Tragopogon porrifolius (I)
 * Triadenum fraseri (N)
 * Triadenum tubulosum (N)
 * Triadenum virginicum (N)
 * Triadenum walteri (N)
 * Triantha glutinosa (N)
 * Tribulus terrestris (I)
 * Trichomanes boschianum (N)
 * Trichomanes intricatum (N)
 * Trichophorum planifolium (N)
 * Trichostema brachiatum (N)
 * Trichostema dichotomum (N)
 * Trichostema setaceum (N)
 * Tridens flavus var. flavus (N)
 * Trientalis borealis ssp. borealis (N)
 * Trifolium ambiguum (I)
 * Trifolium arvense (I)
 * Trifolium aureum (I)
 * Trifolium campestre (I)
 * Trifolium dubium (I)
 * Trifolium hybridum (I)
 * Trifolium incarnatum (I)
 * Trifolium pratense (I)
 * Trifolium reflexum (N)
 * Trifolium repens (I)
 * Trifolium resupinatum (I)
 * Trifolium stoloniferum (N)
 * Triglochin maritima (N)
 * Triglochin palustris (N)
 * Trillium cernuum (N)
 * Trillium erectum (N)
 * Trillium flexipes (N)
 * Trillium grandiflorum (N)
 * Trillium nivale (N)
 * Trillium recurvatum (N)
 * Trillium sessile (N)
 * Trillium undulatum (N)
 * Triodanis perfoliata (N)
 * Triosteum angustifolium (N)
 * Triosteum aurantiacum var. aurantiacum (N)
 * Triosteum aurantiacum var. glaucescens (N)
 * Triosteum aurantiacum var. illinoense (N)
 * Triosteum perfoliatum (N)
 * Triphora trianthophora (N)
 * Triplasis purpurea (N)
 * Tripleurospermum maritimum (N)
 * Tripleurospermum maritimum ssp. maritimum (I)
 * Tripsacum dactyloides (N)
 * Triticum aestivum (I)
 * Trollius laxus ssp. laxus (N)
 * Tsuga canadensis (N)
 * Tulipa gesneriana (I)
 * Tussilago farfara (I)
 * Typha angustifolia (I)
 * Typha angustifolia (N)
 * Typha × glauca (N)
 * Typha latifolia (N)

U

 * Ulmus americana (N)
 * Ulmus procera (I)
 * Ulmus pumila (I)
 * Ulmus rubra (N)
 * Ulmus thomasii (N)
 * Urtica chamaedryoides (N)
 * Urtica dioica ssp. gracilis (N)
 * Urtica dioica ssp. dioica (I)
 * Utricularia cornuta (N)
 * Utricularia geminiscapa (N)
 * Utricularia gibba (N)
 * Utricularia intermedia (N)
 * Utricularia macrorhiza (N)
 * Utricularia minor (N)
 * Uvularia grandiflora (N)
 * Uvularia perfoliata (N)
 * Uvularia sessilifolia (N)

V

 * Vaccaria hispanica (I)
 * Vaccinium angustifolium (N)
 * Vaccinium corymbosum (N)
 * Vaccinium fuscatum (N)
 * Vaccinium macrocarpon (N)
 * Vaccinium myrtilloides (N)
 * Vaccinium oxycoccos (N)
 * Vaccinium pallidum (N)
 * Vaccinium simulatum (N)
 * Vaccinium stamineum (N)
 * Valeriana edulis var. ciliata (N)
 * Valeriana officinalis (I)
 * Valeriana pauciflora (N)
 * Valeriana uliginosa (N)
 * Valerianella chenopodiifolia (N)
 * Valerianella locusta (I)
 * Valerianella radiata (N)
 * Valerianella umbilicata (N)
 * Vallisneria americana (N)
 * Veratrum virginicum (N)
 * Veratrum viride (N)
 * Veratrum woodii (N)
 * Verbascum blattaria (I)
 * Verbascum phlomoides (I)
 * Verbascum phoeniceum (I)
 * Verbascum thapsus (I)
 * Verbascum virgatum (I)
 * Verbena bracteata (N)
 * Verbena × engelmannii (N)
 * Verbena hastata var. hastata (N)
 * Verbena × moechina (N)
 * Verbena simplex (N)
 * Verbena stricta (N)
 * Verbena urticifolia var. leiocarpa (N)
 * Verbena urticifolia var. urticifolia (N)
 * Verbesina alternifolia (N)
 * Verbesina helianthoides (N)
 * Verbesina occidentalis (N)
 * Verbesina virginica var. virginica (N)
 * Vernonia arkansana (N)
 * Vernonia fasciculata ssp. fasciculata (N)
 * Vernonia gigantea ssp. gigantea (N)
 * Vernonia × illinoensis (N)
 * Vernonia missurica (N)
 * Vernonia noveboracensis (N)
 * Veronica agrestis (I)
 * Veronica americana (N)
 * Veronica anagallis-aquatica (N)
 * Veronica arvensis (I)
 * Veronica austriaca ssp. teucrium (I)
 * Veronica beccabunga (I)
 * Veronica chamaedrys (I)
 * Veronica filiformis (I)
 * Veronica hederifolia (I)
 * Veronica officinalis var. officinalis (I)
 * Veronica peregrina ssp. peregrina (N)
 * Veronica peregrina ssp. xalapensis (N)
 * Veronica persica (I)
 * Veronica polita (I)
 * Veronica scutellata (N)
 * Veronica serpyllifolia (N)
 * Veronica serpyllifolia ssp. serpyllifolia (I)
 * Veronica verna (I)
 * Veronicastrum virginicum (N)
 * Viburnum acerifolium (N)
 * Viburnum buddleifolium (I)
 * Viburnum dentatum var. dentatum (N)
 * Viburnum dentatum var. venosum (N)
 * Viburnum lantana (I)
 * Viburnum lantanoides (N)
 * Viburnum lentago (N)
 * Viburnum molle (N)
 * Viburnum nudum var. cassinoides (N)
 * Viburnum opulus var. americanum (N)
 * Viburnum opulus var. opulus (I)
 * Viburnum plicatum (I)
 * Viburnum prunifolium (N)
 * Viburnum rafinesqueanum (N)
 * Viburnum recognitum (N)
 * Viburnum × rhytidophylloides (I)
 * Viburnum rufidulum (N)
 * Vicia americana ssp. americana (N)
 * Vicia caroliniana (N)
 * Vicia cracca ssp. cracca (I)
 * Vicia hirsuta (I)
 * Vicia sativa ssp. nigra (I)
 * Vicia sativa ssp. sativa (I)
 * Vicia tetrasperma (I)
 * Vicia villosa ssp. varia (I)
 * Vicia villosa ssp. villosa (I)
 * Vigna unguiculata (I)
 * Vinca major (I)
 * Vinca minor (I)
 * Viola affinis (N)
 * Viola arvensis (I)
 * Viola × bernardii (N)
 * Viola bicolor (N)
 * Viola × bissellii (N)
 * Viola blanda var. blanda (N)
 * Viola blanda var. palustriformis (N)
 * Viola × brauniae (N)
 * Viola canadensis var. canadensis (N)
 * Viola × conjugens (N)
 * Viola × consobrina (N)
 * Viola × cooperrideri (N)
 * Viola × cordifolia (N)
 * Viola cucullata (N)
 * Viola × eclipes (N)
 * Viola × filicetorum (N)
 * Viola hastata (N)
 * Viola hirsutula (N)
 * Viola labradorica (N)
 * Viola lanceolata ssp. lanceolata (N)
 * Viola macloskeyi ssp. pallens (N)
 * Viola × malteana (N)
 * Viola missouriensis (N)
 * Viola nephrophylla (N)
 * Viola odorata (I)
 * Viola × palmata (N)
 * Viola pedata (N)
 * Viola pedatifida (N)
 * Viola × populifolia (N)
 * Viola × primulifolia (N)
 * Viola pubescens var. pubescens (N)
 * Viola pubescens var. scabriuscula (N)
 * Viola × ravida (N)
 * Viola rostrata (N)
 * Viola rotundifolia (N)
 * Viola sagittata var. ovata (N)
 * Viola sagittata var. sagittata (N)
 * Viola selkirkii (N)
 * Viola × slavinii (N)
 * Viola sororia (N)
 * Viola striata (N)
 * Viola tricolor (I)
 * Viola triloba var. dilatata (N)
 * Viola triloba var. triloba (N)
 * Viola tripartita (N)
 * Viola walteri (N)
 * Viola × wittrockiana (I)
 * Vitex negundo var. heterophylla (I)
 * Vitis aestivalis var. aestivalis (N)
 * Vitis aestivalis var. bicolor (N)
 * Vitis cinerea var. baileyana (N)
 * Vitis labrusca (N)
 * Vitis riparia (N)
 * Vitis vulpina (N)
 * Vittaria appalachiana (N)
 * Vulpia bromoides (I)
 * Vulpia myuros (I)
 * Vulpia octoflora var. glauca (N)

W

 * Waldsteinia fragarioides ssp. fragarioides (N)
 * Wisteria floribunda (I)
 * Wisteria frutescens (N)
 * Wolffia borealis (N)
 * Wolffia brasiliensis (N)
 * Wolffia columbiana (N)
 * Wolffiella gladiata (N)
 * Woodsia ilvensis (N)
 * Woodwardia virginica (N)

X

 * Xanthium spinosum (I)
 * Xanthium strumarium var. canadense (N)
 * Xanthium strumarium var. glabratum (N)
 * Xanthorhiza simplicissima (N)
 * Xyris difformis var. difformis (N)
 * Xyris torta (N)

Y

 * Yucca filamentosa (N)

Z

 * Zannichellia palustris (N)
 * Zanthoxylum americanum (N)
 * Zea mays ssp. mays (I)
 * Zelkova serrata (I)
 * Zigadenus elegans ssp. glaucus (N)
 * Zizania aquatica var. aquatica (N)
 * Zizania palustris var. interior (N)
 * Zizia aptera (N)
 * Zizia aurea (N)