# List of flora of Ohio

This list includes plants native and introduced to the state of Ohio, designated (N) and (I), respectively. Varieties and subspecies link to their parent species.
* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* See also
* References
* External links

## 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)
* Acer × freemanii (N)
* Acer ginnala (I)
* Acer negundo var. negundo (N)
* Acer negundo var. violaceum (N)
* Acer nigrum (N)
* Acer palmatum (I)
* Acer pensylvanicum (N)
* Acer platanoides (I)
* Acer rubrum var. rubrum (N)
* Acer rubrum var. trilobum (N)
* Acer saccharinum (N)
* Acer saccharum var. saccharum (N)
* Acer spicatum (N)
* 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)
* Adenocaulon bicolor (N)
* 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)
* 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)
* 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)
* Amaranthus blitoides (I)
* Amaranthus blitum var. emarginatus (I)
* Amaranthus cruentus (I)
* Amaranthus deflexus (I)
* Amaranthus hybridus (N)
* Amaranthus palmeri (N)
* 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)
* Asclepias exaltata (N)
* Asclepias hirtella (N)
* Asclepias incarnata ssp. incarnata (N)
* Asclepias purpurascens (N)
* Asclepias quadrifolia (N)
* Asclepias sullivantii (N)
* Asclepias syriaca (N)
* Asclepias tuberosa ssp. interior (N)
* Asclepias tuberosa ssp. tuberosa (N)
* Asclepias variegata (N)
* Asclepias verticillata (N)
* Asclepias viridiflora (N)
* Asclepias viridis (N)
* Asimina triloba (N)
* Asparagus officinalis (I)
* Asperugo procumbens (I)
* Asplenium bradleyi (N)
* 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 canadensis (N)
* Berberis × ottawensis (N)
* Berberis thunbergii (I)
* Berberis vulgaris (I)
* Berteroa incana (I)
* Besseya bullii (N)
* Betula alleghaniensis var. alleghaniensis (N)
* Betula alleghaniensis var. macrolepis (N)
* Betula lenta (N)
* Betula nigra (N)
* Betula papyrifera var. papyrifera (N)
* Betula pendula (I)
* Betula populifolia (N)
* Betula pubescens (N)
* Betula pubescens ssp. pubescens (I)
* Betula pumila var. pumila (N)
* Betula × purpusii (N)
* Bidens aristosa (N)
* 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)
* 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)
* Carex albicans var. albicans (N)
* Carex albicans var. emmonsii (N)
* Carex albolutescens (N)
* Carex albursina (N)
* Carex alopecoidea (N)
* Carex amphibola (N)
* 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)
* Cirsium arvense (I)
* Cirsium canescens (N)
* Cirsium carolinianum (N)
* Cirsium discolor (N)
* Cirsium muticum (N)
* Cirsium pumilum (N)
* Cirsium vulgare (I)
* 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)
* Coreopsis lanceolata (N)
* Coreopsis major (N)
* Coreopsis tinctoria var. tinctoria (N)
* Coreopsis tripteris (N)
* Coreopsis verticillata (N)
* 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)
* Crataegus holmesiana (N)
* Crataegus × hudsonica (N)
* Crataegus × immanis (N)
* Crataegus indicens (N)
* Crataegus intricata (N)
* Crataegus iracunda (N)
* Crataegus irrasa (N)
* Crataegus jesupii (N)
* Crataegus lucorum (N)
* Crataegus macrosperma (N)
* 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)
* 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)
* Cyperus amuricus (I)
* Cyperus bipartitus (N)
* Cyperus compressus (N)
* Cyperus diandrus (N)
* Cyperus echinatus (N)
* Cyperus erythrorhizos (N)
* Cyperus esculentus (N)
* Cyperus esculentus var. leptostachyus (I)
* Cyperus flavescens (N)
* Cyperus houghtonii (N)
* Cyperus iria (I)
* Cyperus lancastriensis (N)
* Cyperus lupulinus ssp. lupulinus (N)
* Cyperus lupulinus ssp. macilentus (N)
* Cyperus odoratus (N)
* Cyperus refractus (N)
* Cyperus retrofractus (N)
* Cyperus schweinitzii (N)
* Cyperus squarrosus (N)
* Cyperus strigosus (N)
* 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)
* Franklinia alatamaha (I)
* 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)
* Salicornia maritima (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)
* Torreya taxifolia (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)