Vascular Plants of Massachusetts

The Second Edition of the County Checklist (2011) at Salicicola
View species by county and status.

After M. Dow Cullina, B. Connolly, B. Sorrie, and P. Somers. 2011
Names of species represented at salicicola gallery (in darkred) are clickable.

Abies balsamea (L.) P. Miller — Balsam Fir [S4] [I]; Pinaceae -- 27 published photos
Abutilon theophrasti Medicus — Velvet-leaf [SNA] [I]; Malvaceae -- 2 published photos
Acalypha rhomboidea Raf. — Broad Three-seeded Mercury [S4?] [N]; Euphorbiaceae -- 7 published photos
Acalypha virginica L. — Three-seeded Mercury [WL] [S1S2] [N]; Euphorbiaceae
Acer ginnala Maxim. — Amur Maple [SNA] [I]; Sapindaceae
Acer negundo L. var. negundo — Boxelder [S4] [I]; Sapindaceae in Aceraceae -- 5 published photos
Acer pensylvanicum L. — Striped Maple [S4S5] [I]; Sapindaceae in Aceraceae -- 21 published photos
Acer platanoides L. — Norway Maple [invasive] [SNA] [I]; Sapindaceae in Aceraceae -- 18 published photos
Acer pseudoplatanus L. — Sycamore-maple [invasive] [SNA] [I]; Sapindaceae in Aceraceae -- 11 published photos
Acer rubrum L. — Red Maple [S5] [N]; Sapindaceae in Aceraceae -- 61 published photos
Acer saccharinum L. — Silver Maple [S4] [N]; Sapindaceae in Aceraceae -- 27 published photos
Acer saccharum Marsh. var. saccharum — Sugar-maple [S5] [N]; Sapindaceae in Aceraceae -- 16 published photos
Achillea millefolium L. ssp. millefolium — Yarrow [SNA] [I]; Asteraceae -- 9 published photos
Achillea ptarmica L. — Sneezeweed [SNA] [I]; Asteraceae
Acorus calamus L. — Sweet Flag [SNA] [I]; Acoraceae in Araceae -- 16 published photos
Actaea pachypoda Ell. — Doll's Eyes [S4S5] [N]; Ranunculaceae -- 12 published photos
Actaea rubra (Aiton) Willd. — Red Baneberry [S4S5] [N]; Ranunculaceae
Adiantum pedatum L. — Maidenhair-fern [S4] [N]; Pteridaceae in Adiantaceae -- 9 published photos
Aegopodium podagraria L. — Goutweed [invasive] [SNA] [I]; Apiaceae -- 14 published photos
Aesculus hippocastanum L. — Horse-chestnut [SNA] [I]; Sapindaceae in Hippocastanaceae -- 4 published photos
Aethusa cynapium L. — Fool's Parsley [SNA] [I]; Apiaceae -- 13 published photos
Agalinis maritima (Raf.) Raf. ssp. maritima — Seaside Gerardia [S4] [N]; Orobanchaceae in Scrophulariaceae -- 12 published photos
Agalinis paupercula (A. Gray) Britton var. paupercula — Small-flowered Gerardia [S5] [N]; Orobanchaceae in Scrophulariaceae
Agalinis purpurea (L.) Pennell — Purple Gerardia [S4] [N]; Orobanchaceae in Scrophulariaceae -- 22 published photos
Agalinis tenuifolia (Vahl.) Raf. var. tenuifolia — Slender Gerardia [S4] [N]; Orobanchaceae in Scrophulariaceae -- 6 published photos
Ageratina altissima (L.) King & H.E. Robinson — White Snakeroot [S4S5] [I]; Asteraceae -- 14 published photos
Ageratina aromatica (L.) Spach — Lesser Snakeroot [E] [S1] [N]; Asteraceae
Agrimonia gryposepala Wallr. — Common Agrimony [S5] [N]; Rosaceae -- 9 published photos
Agrostemma githago L. var. githago — Corn-cockle [SNA] [I]; Caryophyllaceae
Agrostis capillaris L. — Rhode Island Bentgrass [SNA] [I]; Poaceae
Agrostis elliottiana J.A. Schultes — Elliott's Bentgrass [SNA] [?]; Poaceae
Agrostis gigantea Roth — Redtop [SNA] [I]; Poaceae
Agrostis hyemalis (Walter) B.S.P. — Southern Ticklegrass [S4] [N]; Poaceae
Agrostis perennans (Walter) Tuckerman — Upland Bentgrass [S5] [N]; Poaceae
Agrostis scabra Willd. — Northern Ticklegrass [S5] [N]; Poaceae -- 9 published photos
Agrostis stolonifera L. — Marsh Bentgrass [S5] [I?]; Poaceae
Ailanthus altissima (P. Miller) Swingle — Tree-of-heaven [invasive] [SNA] [I]; Simaroubaceae -- 42 published photos
Aira caryophyllea L. var. caryophyllea — Silvery Hairgrass [SNA] [I]; Poaceae -- 8 published photos
Aira praecox L. — Strict Hairgrass [SNA] [I]; Poaceae -- 8 published photos
Ajuga reptans L. — Carpet-bugleweed [SNA] [I]; Lamiaceae -- 4 published photos
Aletris farinosa L. — Colic-root [S4] [N]; Nartheciaceae in Liliaceae -- 9 published photos
Alliaria petiolata (Bieb.) Cavara & Grande — Garlic-mustard [invasive] [SNA] [I]; Brassicaceae -- 11 published photos
Allium canadense L. var. canadense — Wild Garlic [S5] [N]; Alliaceae in Liliaceae -- 3 published photos
Allium vineale L. — Field Garlic [SNA] [I]; Alliaceae in Liliaceae -- 5 published photos
Alnus glutinosa (L.) Gaertner — Black Alder [SNA] [I]; Betulaceae -- 12 published photos
Alnus incana (L.) Moench ssp. rugosa (Du Roi) Clausen — Speckled Alder [S5] [N]; Betulaceae as Alnus rugosa -- 35 published photos
Alnus serrulata (Aiton) Willd. — Smooth Alder [S5] [N]; Betulaceae -- 25 published photos
Alopecurus aequalis Sobol. — Short-awned Foxtail [S5] [N]; Poaceae
Alopecurus geniculatus L. — Marsh Foxtail [SNA] [I]; Poaceae
Alopecurus pratensis L. — Meadow Foxtail [SNA] [I]; Poaceae -- 2 published photos
Amaranthus blitoides S. Watson — Tumbleweed [SNA] [I]; Amaranthaceae -- 4 published photos
Amaranthus cannabinus (L.) Sauer — Saltmarsh-hemp [S4] [N]; Amaranthaceae
Amaranthus hybridus L. — Green Amaranth [SNA] [I]; Amaranthaceae -- 2 published photos
Amaranthus powellii S. Watson — Powell's Amaranth [SNA] [I]; Amaranthaceae
Amaranthus retroflexus L. — Redroot [SNA] [I]; Amaranthaceae
Ambrosia artemisiifolia L. — Ragweed [S5] [N]; Asteraceae -- 14 published photos
Ambrosia trifida L. — Giant Ragweed [S5] [N]; Asteraceae
Amelanchier canadensis (L.) Medicus — Thicket Shadbush [S5] [N]; Rosaceae -- 34 published photos
Amelanchier laevis Wieg. — Smooth Shadbush [S5] [N]; Rosaceae -- 8 published photos
Amelanchier nantucketensis Bicknell — Nantucket Shadbush [WL] [S3S4] [N]; Rosaceae -- 10 published photos
Amelanchier spicata (Lam.) K. Koch — Running Shadbush [S5] [N]; Rosaceae -- 34 published photos
Ammophila breviligulata Fern. ssp. breviligulata — Dunegrass [S4] [N]; Poaceae -- 19 published photos
Amorpha fruticosa L. — False Indigo [SNA] [I]; Fabaceae -- 13 published photos
Ampelopsis heterophylla (Thunb.) Sieb. & Zucc. var. brevipedunculata C.L. Li — Porcelain-berry [likely invasive] [SNA] [I]; Vitaceae as Ampelopsis brevipedunculata -- 8 published photos
Amphicarpaea bracteata (L.) Fern. — Hog-peanut [S5] [N]; Fabaceae -- 7 published photos
Anagallis arvensis L. — Scarlet Pimpernel [SNA] [I]; Myrsinaceae in Primulaceae -- 6 published photos
Anaphalis margaritacea (L.) Bentham & Hooker f. — Pearly Everlasting [S5] [N]; Asteraceae
Andropogon gerardii Vitman — Big Bluestem [S5] [N]; Poaceae -- 19 published photos
Andropogon glomeratus (Walter) B.S.P. var. glomeratus — Bunched Broom-sedge [S4] [N]; Poaceae -- 13 published photos
Andropogon virginicus L. virginicus — Broom-sedge [S4] [N]; Poaceae -- 7 published photos
Anemone americana (DC.) H. Hara — Blunt-lobed Hepatica [S4] [N]; Ranunculaceae as Hepatica nobilis var. obtusa -- 17 published photos
Anemone quinquefolia L. var. quinquefolia — Wood-anemone [S5] [N]; Ranunculaceae -- 22 published photos
Anemone virginiana L. var. virginiana — Stout Thimbleweed [S5] [N]; Ranunculaceae -- 1 published photos
Angelica lucida L. — Seaside-angelica [WL] [S2?] [N]; Apiaceae -- 20 published photos
Antennaria howellii Greene ssp. canadensis (Greene) Bayer — Canadian Pussytoes [S5] [N]; Asteraceae
Antennaria howellii Greene ssp. petaloidea (Fern.) Bayer — Field-pussytoes [S5] [N]; Asteraceae
Antennaria howellii Greene ssp. neodioica (Greene) Bayer — Greene's Pussytoes [S5] [N]; Asteraceae as Antennaria neodioica -- 10 published photos
Antennaria neglecta Greene — Pussytoes [S5] [N]; Asteraceae -- 6 published photos
Antennaria parlinii Fern. ssp. fallax (Greene) Bayer & Stebbins — Broad-leaved Pussytoes [S5] [N]; Asteraceae
Antennaria plantaginifolia (L.) Richardson — Plantain-leaved Pussytoes [S5] [N]; Asteraceae -- 9 published photos
Anthemis arvensis L. — Dog-chamomile, corn-camomile [SNA] [I]; Asteraceae
Anthemis cotula L. — Mayweed [SNA] [I]; Asteraceae
Anthoxanthum nitens (Weber) Y. Schouten & Veldkamp ssp. nitens — Sweet Grass [S4S5] [N]; Poaceae
Anthoxanthum odoratum L. — Sweet Vernalgrass [S5] [I]; Poaceae -- 15 published photos
Apios americana Medicus — Groundnut [S5] [N]; Fabaceae -- 10 published photos
Apocynum androsaemifolium L. — Spreading Dogbane [S5] [N]; Apocynaceae -- 14 published photos
Apocynum cannabinum L. — Prairie-dogbane [S4] [N]; Apocynaceae -- 7 published photos
Apocynum ×floribundum Greene [S4] [N]; Apocynaceae
Aquilegia canadensis L. — Wild Columbine [S5] [N]; Ranunculaceae -- 26 published photos
Arabidopsis thaliana (L.) Heynh. — Mouse-ear Cress [SNA] [I]; Brassicaceae -- 25 published photos
Aralia hispida Vent. — Bristly Sarsaparilla [S5] [N]; Apiaceae in Araliaceae -- 20 published photos
Aralia nudicaulis L. — Wild Sarsaparilla [S5] [N]; Apiaceae in Araliaceae -- 19 published photos
Aralia racemosa L. ssp. racemosa — Spikenard [S4] [N]; Apiaceae in Araliaceae
Arctium lappa L. — Great Burdock [SNA] [I]; Asteraceae -- 8 published photos
Arctium minus Bernh. — Common Burdock [SNA] [I]; Asteraceae -- 7 published photos
Arctostaphylos uva-ursi (L.) Sprengel — Bearberry [S5] [N]; Ericaceae -- 23 published photos
Arenaria serpyllifolia L. — Thyme-leaf Sandwort [SNA] [I]; Caryophyllaceae
Arethusa bulbosa L. — arethusa [T] [S2] [N]; Orchidaceae -- 7 published photos
Argemone albiflora Hornem. ssp. albiflora — White Prickly-poppy [SNA] [W]; Papaveraceae
Argemone mexicana L. — Yellow Prickly-poppy [SNA] [I]; Papaveraceae
Argentina egedii (Wormsk.) Rydb. ssp. groenlandica — Saltmarsh Silverweed [S4] [N]; Rosaceae as Potentilla egedii ssp. groenlandica -- 9 published photos
Arisaema stewardsonii (Britton) Huttleston — Swamp Jack-in-the-pulpit [E] [S5] [N]; Araceae
Arisaema triphyllum ssp. triphyllum (L.) Schott ex — Schott & Endl. Woodland Jack-in-the-pulpit [S5] [N]; Araceae -- 16 published photos
Aristida dichotoma Michaux var. dichotoma — Poverty-grass [S5] [N]; Poaceae -- 5 published photos
Aristida longespica Poiret var. geniculata (Raf.) Fern. — Barrens Needle-grass [SNA] [N]; Poaceae as Aristida longespica var. geniculata
Aristida oligantha Michaux — Prairie Needle-grass [SNA] [I]; Poaceae
Aristida purpurascens Poiret — Purple Needle-grass [T] [S2] [N]; Poaceae
Aristida tuberculosa Nutt. — Seabeach Needle-grass [T] [S2] [N]; Poaceae
Armoracia rusticana Gaertner, Meyer, & Scherb. — Horse-radish [SNA] [I]; Brassicaceae
Aronia arbutifolia (L.) Ell. — Red Chokeberry [S4S5] [N]; Rosaceae
Aronia melanocarpa (Michaux) Ell. — Black Chokeberry [S5] [N]; Rosaceae -- 26 published photos
Aronia ×floribunda (Lindl.) Spach — Purple Chokeberry [S5] [N]; Rosaceae as Aronia x prunifolia -- 19 published photos
Arrhenatherum elatius (L.) J. & K. Presl ssp. elatius — Tall Oatgrass [SNA] [I]; Poaceae -- 9 published photos
Arrhenatherum elatius ssp. bulbosum (Willd.) Schübler & Martens — Bulbous Tall Oatgrass [SNA] [W]; Poaceae
Artemisia absinthium L. — Absinthe [SNA] [I]; Asteraceae
Artemisia campestris L. ssp. caudata (Michaux) Hall & Clements — Tall Wormwood [S4] [N]; Asteraceae as Artemisia campestris ssp. caudata -- 19 published photos
Artemisia stelleriana Besser — Dusty Miller [SNA] [I]; Asteraceae -- 16 published photos
Artemisia vulgaris L. — Mugwort [SNA] [I]; Asteraceae -- 11 published photos
Asclepias amplexicaulis J.E. Smith — Blunt-leaved Milkweed [S45] [N]; Apocynaceae in Asclepiadaceae -- 13 published photos
Asclepias exaltata L. — Poke-milkweed [S5] [N]; Apocynaceae in Asclepiadaceae -- 5 published photos
Asclepias incarnata L. ssp. pulchra (Ehrh. ex Willd.) Woodson — Downy Swamp-milkweed [S5] [N]; Apocynaceae as Asclepias incarnata ssp. pulchra in Asclepiadaceae -- 27 published photos
Asclepias quadrifolia Jacq. — Four-leaved Milkweed [S4] [N]; Apocynaceae in Asclepiadaceae -- 3 published photos
Asclepias syriaca L. — Common Milkweed [S5] [N]; Apocynaceae in Asclepiadaceae -- 24 published photos
Asclepias tuberosa L. — Orange Milkweed [WL] [S4] [N]; Apocynaceae in Asclepiadaceae -- 15 published photos
Asclepias verticillata L. — Whorled Milkweed [T] [S2] [N]; Apocynaceae
Asparagus officinalis L. — asparagus [SNA] [I]; Asparagaceae in Liliaceae -- 11 published photos
Asplenium platyneuron (L.) B.S.P. — Ebony Spleenwort [S5] [N]; Aspleniaceae -- 12 published photos
Athyrium angustum (Willd.) C. Presl. — Northern Lady-fern [S5] [N]; Woodsiaceae as Athyrium filix-femina var. angustum in Dryopteridaceae -- 24 published photos
Atriplex cristata Humb. & Bonpl. ex Willd. — Seabeach Orache [S4] [N]; Amaranthaceae in Chenopodiaceae -- 10 published photos
Atriplex glabriuscula Edmonston — Prostrate Orache [WL] [S1S2] [N]; Amaranthaceae in Chenopodiaceae -- 12 published photos
Atriplex littoralis L. — Seaside Orache [S4] [N]; Amaranthaceae in Chenopodiaceae
Atriplex patula L. — Orache [SNA] [I]; Amaranthaceae in Chenopodiaceae
Atriplex prostrata Boucher ex DC. — Halberd-leaf Orache [S4] [N]; Amaranthaceae in Chenopodiaceae -- 22 published photos
Atriplex rosea L. — Red Orache [SNA] [W]; Amaranthaceae
Atriplex subspicata (Nutt.) Rydb. — Halberd-leaf Orache [H] [SH] [N]; Amaranthaceae
Aureolaria flava (L.) Farw. var. flava — Smooth False Foxglove [S4] [N]; Orobanchaceae in Scrophulariaceae
Aureolaria pedicularia (L.) Raf. var. pedicularia — Fern-leaf False Foxglove [S4] [N]; Orobanchaceae in Scrophulariaceae -- 24 published photos
Aureolaria virginica (L.) Pennell — Downy False Foxglove [S4?] [N]; Orobanchaceae in Scrophulariaceae -- 6 published photos
Avena sativa L. — Oats [SNA] [I]; Poaceae -- 1 published photos
Baccharis halimifolia L. — Groundsel-tree [S4] [N]; Asteraceae -- 19 published photos
Ballota nigra L. var. nigra — Black Horehound [SNA] [W]; Lamiaceae
Baptisia tinctoria (L.) R. Br. ex Aiton f. — Yellow Wild Indigo [S5] [N]; Fabaceae -- 10 published photos
Barbarea vulgaris Aiton f. — Winter-cress [SNA] [I]; Brassicaceae -- 31 published photos
Bartonia paniculata (Michaux) Muhl. ssp. paniculata — Screw-stem [S4] [N]; Gentianaceae -- 4 published photos
Bartonia virginica (L.) B.S.P. — Screw-stem [S4] [N]; Gentianaceae -- 16 published photos
Bassia hirsuta (L.) Aschers. — Downy Seablite [SNA] [I]; Amaranthaceae
Bellis perennis L. — English Daisy [SNA] [I]; Asteraceae
Benthamidia florida (L.) Spach — Flowering Dogwood [S5] [N]; Cornaceae as Cornus florida -- 25 published photos
Berberis thunbergii DC. — Japanese Barberry [invasive] [SNA] [I]; Berberidaceae -- 16 published photos
Berberis vulgaris L. — European Barberry [likely invasive] [SNA] [I]; Berberidaceae -- 15 published photos
Berteroa incana (L.) DC. — Hoary Alyssum [SNA] [I]; Brassicaceae -- 5 published photos
Berteroa mutabilis (Vent.) DC. — Flatpod-alyssum [SNA] [W]; Brassicaceae
Betula alleghaniensis Britton — Yellow Birch [S5] [N]; Betulaceae -- 29 published photos
Betula lenta L. — Black Birch [S5] [N]; Betulaceae -- 17 published photos
Betula papyrifera Marsh. — Paper-birch [S5] [N]; Betulaceae -- 27 published photos
Betula populifolia Marsh. — Gray Birch [S5] [N]; Betulaceae -- 32 published photos
Bidens cernua L. — Nodding Bur-marigold [S5] [N]; Asteraceae -- 4 published photos
Bidens connata Muhl. ex Willd. — Swamp Beggar-ticks [S5] [N]; Asteraceae -- 11 published photos
Bidens discoidea (Torrey & A. Gray) Britton — Small Beggar-ticks [S4] [N]; Asteraceae -- 7 published photos
Bidens frondosa L. — Devil's Pitchforks [S5] [N]; Asteraceae -- 12 published photos
Bidens hyperborea Greene — Estuary Beggar-ticks [E] [S1] [N]; Asteraceae
Bidens laevis (L.) B.S.P. — Smooth Bur-marigold [S4] [N]; Asteraceae
Bidens trichosperma (Michaux) Britton — Northern Tickseed-sunflower [S3S4] [N]; Asteraceae as Bidens coronata -- 9 published photos
Bidens vulgata Greene — Tall Beggar-ticks [S5] [N]; Asteraceae -- 7 published photos
Boechera canadensis (L.) Al-Shehbaz — Sickle-pod [S4] [N]; Brassicaceae as Arabis canadensis -- 8 published photos
Boehmeria cylindrica (L.) Sw. — False Nettle [S5] [N]; Urticaceae -- 10 published photos
Bolboschoenus maritimus (L.) Palla × B. robustus (Pursh) Soják [SNR] [N]; Cyperaceae
Bolboschoenus maritimus (L.) Palla ssp. paludosus (A. Nels.) T. Koyama — Seaside Bulrush [S5] [N]; Cyperaceae as Bolboschoenus maritimus ssp. paludosus
Bolboschoenus novae-angliae (Britton) S.G. Smith — Long-spiked Bulrush [WL] [S2?] [N]; Cyperaceae
Bolboschoenus robustus (Pursh) Soják — Saltmarsh Bulrush [S5] [N]; Cyperaceae as Scirpus robustus -- 11 published photos
Botrychium dissectum Sprengel — Dissected Grape-fern [S4?] [N]; Ophioglossaceae -- 8 published photos
Botrychium matricariifolium (Doll) A. Braun ex W.D.J. Koch — Daisy-leaf Moonwort [WL] [S2?] [N]; Ophioglossaceae
Botrychium oneidense (Gilbert) House — Blunt-lobed Grape-fern [WL] [S1S2] [N]; Ophioglossaceae
Botrychium tenebrosum A. A. Eaton — Swamp Moonwort [WL] [S1S2] [N]; Ophioglossaceae
Botrychium virginianum (L.) Sw. — Rattlesnake-fern [S5] [N]; Ophioglossaceae -- 11 published photos
Brachyelytrum aristosum (Michaux) Trel. in Branner & Coville — Woodgrass [S5] [N]; Poaceae as Brachyelytrum septentrionale -- 6 published photos
Brasenia schreberi J.F. Gmelin — Water-shield [S5] [N]; Nymphaeaceae in Cabombaceae -- 24 published photos
Brassica juncea (L.) Czern. — Brown Mustard [SNA] [I]; Brassicaceae
Brassica napus L. — Rutabaga [SNA] [W]; Brassicaceae
Brassica nigra (L.) W.D.J. Koch — Black Mustard [SNA] [I]; Brassicaceae
Brassica rapa L. — Turnip [SNA] [I]; Brassicaceae
Briza media L. — Quaking Grass [SNA] [I]; Poaceae
Bromus ciliatus L. — Fringed Brome [S5] [N]; Poaceae
Bromus commutatus Schrader — Hairy Chess [SNA] [I]; Poaceae
Bromus erectus Hudson — Upright Brome [SNA] [W]; Poaceae
Bromus hordeaceus L. ssp. hordeaceus — Soft Brome [SNA] [I]; Poaceae
Bromus inermis Leysser ssp. inermis — Smooth Brome [SNA] [I]; Poaceae -- 4 published photos
Bromus secalinus L. — Cheat [SNA] [I]; Poaceae
Bromus tectorum L. — Drooping Brome [I]; Poaceae -- 7 published photos
Buglossoides arvensis (L.) I.M. Johnston ssp. arvensis — Corn-gromwell [SNA] [I]; Boraginaceae
Bulbostylis capillaris (L.) Kunth ex C.B. Clarke — Sand-sedge [S5] [N]; Cyperaceae -- 13 published photos
Cabomba caroliniana A. Gray — Fanwort [invasive] [SNA] [I]; Nymphaeaceae in Cabombaceae -- 34 published photos
Cakile edentula (Bigelow) Hooker ssp. edentula var. edentula — Sea-rocket [S4S5] [N]; Brassicaceae -- 17 published photos
Calamagrostis canadensis (Michaux) Beauv. var. canadensis — Canada Bluejoint or Reedgrass [S5] [N]; Poaceae -- 34 published photos
Calamagrostis cinnoides (Muhl.) Bart. — Reed-bluejoint [S5] [N]; Poaceae -- 15 published photos
Calamagrostis epigejos (L.) Roth var. georgica (K. Koch) Ledeb. — Feathertop [SNA] [I]; Poaceae as Calamagrostis epigeios -- 10 published photos
Calamagrostis pickeringii A. Gray — Pickering's Reedgrass [E] [S1] [N]; Poaceae -- 16 published photos
Calla palustris L. — Wild Calla [S4] [N]; Araceae -- 15 published photos
Callitriche heterophylla Pursh var. heterophylla — Variable Water-starwort [S5] [N]; Plantaginaceae in Callitrichaceae -- 8 published photos
Callitriche stagnalis Scop. — Stream Water-starwort [SNA] [I]; Plantaginaceae in Callitrichaceae -- 31 published photos
Calluna vulgaris (L.) Hull — Heather [SNA] [I]; Ericaceae -- 16 published photos
Calopogon tuberosus (L.) B.S.P. — Grass-pink [S4] [N]; Orchidaceae -- 8 published photos
Caltha palustris L. — Marsh-marigold [S5] [N]; Ranunculaceae -- 9 published photos
Calystegia sepium (L.) R. Br. ssp. americana (Sims) Brummitt — Wild Morning-glory [S5] [N]; Convolvulaceae -- 9 published photos
Calystegia sepium (L.) R. Br. ssp. sepium — European Morning-glory, Hedge-bindweed [SNA] [I]; Convolvulaceae -- 9 published photos
Camelina microcarpa Andrz. ex DC. — Small-seeded False Flax [SNA] [I]; Brassicaceae
Campanula rapunculoides L. — Creeping Bellflower [SNA] [I]; Campanulaceae -- 3 published photos
Campsis radicans (L.) Seemann ex Bureau — Trumpet-creeper [SNA] [I]; Bignoniaceae -- 10 published photos
Cannabis sativa L. — Marijuana, Hemp [SNA] [I]; Cannabaceae
Capnoides sempervirens (L.) Borkh. — Pink Corydalis [S4] [N]; Papaveraceae as Corydalis sempervirens in Fumariaceae -- 19 published photos
Capsella bursa-pastoris (L.) Medik. — Shepherd's Purse [SNA] [I]; Brassicaceae -- 14 published photos
Cardamine longii Fern. — Long's Bittercress [E] [S1] [N]; Brassicaceae
Cardamine parviflora L. var. arenicola (Britton) O.E. Schulz — Small-flowered Bittercress [S4] [N]; Brassicaceae as Cardamine parviflora var. arenicola -- 11 published photos
Cardamine pensylvanica Muhl. ex Willd. — Pennsylvania Bittercress [S5] [N]; Brassicaceae -- 4 published photos
Carduus nutans L. — Nodding Thistle [SNA] [I]; Asteraceae
Carex abscondita Mackenzie — Concealed Sedge [WL] [S2?] [N]; Cyperaceae
Carex alata Torrey — Winged Sedge [S4] [N]; Cyperaceae
Carex albicans Willd. ex Sprengel var. emmonsii — Emmons' Sedge [S5] [N]; Cyperaceae as Carex albicans var. emmonsii -- 5 published photos
Carex annectens (Bicknell) Bicknell — Yellow Fox-sedge [S5] [N]; Cyperaceae -- 9 published photos
Carex appalachica Webber & Ball — Appalachian Sedge [S5] [N]; Cyperaceae
Carex argyrantha Tuckerman — Silvery Sedge [S5] [N]; Cyperaceae -- 5 published photos
Carex atlantica Bailey ssp. atlantica — Eastern or Atlantic Prickly Sedge [S5] [N]; Cyperaceae
Carex atlantica Bailey ssp. capillacea (Bailey) — Reznicek Howe's Prickly Sedge [S5] [N]; Cyperaceae as Carex atlantica ssp. capillacea -- 8 published photos
Carex billingsii (Knight) C.D. Kirschbaum — Three-seeded Bog-sedge [S5] [N]; Cyperaceae -- 6 published photos
Carex blanda Dewey — Woodland-sedge [S5] [N]; Cyperaceae -- 6 published photos
Carex bromoides Schkuhr ex Willd. — Brome-like Sedge [S5] [N]; Cyperaceae -- 6 published photos
Carex brunnescens (Pers.) Poiret ex Lam. var. sphaerostachya (Tuckerman) Kukenth. — Brownish Sedge [S5] [N]; Cyperaceae as Carex brunnescens
Carex bullata Schkuhr ex Willd. — Button-sedge [S5] [N]; Cyperaceae -- 18 published photos
Carex buxbaumii Wahlenb. — Buxbaum's Sedge [WL] [S2?] [N]; Cyperaceae
Carex canescens L. ssp. disjuncta (Fern.) Toivonen — Silvery Bog-sedge [S5] [N]; Cyperaceae as Carex canescens ssp. disjuncta -- 5 published photos
Carex cephalophora Muhl. ex Willd. — Oval-headed Sedge [S5] [N]; Cyperaceae -- 11 published photos
Carex communis Bailey var. communis — Colonial Sedge [S5] [N]; Cyperaceae -- 8 published photos
Carex comosa Boott — Bristly Sedge [S5] [N]; Cyperaceae -- 19 published photos
Carex conoidea Schkuhr ex Willd. — Field-sedge [S5] [N]; Cyperaceae
Carex crinita Lam. var. crinita — Awned Sedge [S?] [N]; Cyperaceae -- 13 published photos
Carex cumulata (Bailey) Mackenzie — Crowded Sedge [S4] [N]; Cyperaceae -- 14 published photos
Carex debilis Michaux var. rudgei Bailey — Northern Stalked Sedge [S5] [N]; Cyperaceae as Carex canescens ssp. disjuncta -- 5 published photos
Carex digitalis Willd. var. digitalis — Slender-spiked Woodland-sedge [S5] [N]; Cyperaceae
Carex echinata Murray ssp. echinata — Prickly Sedge [S5] [N]; Cyperaceae -- 1 published photos
Carex folliculata L. — Long-culmed Sedge [S5] [N]; Cyperaceae -- 15 published photos
Carex gracillima Schwein. — Graceful Sedge [S5] [N]; Cyperaceae -- 2 published photos
Carex gynandra Schwein. — Northern Awned Sedge [S5] [N]; Cyperaceae -- 6 published photos
Carex haydenii Dewey — Hayden's Sedge [WL] [S1S2] [N]; Cyperaceae -- 6 published photos
Carex hormathodes Fern. — Saltmarsh Straw-sedge [S5] [N]; Cyperaceae -- 8 published photos
Carex intumescens Rudge — Bladder Sedge [S5] [N]; Cyperaceae -- 14 published photos
Carex lacustris Willd. — Lakeside Sedge [S5] [N]; Cyperaceae -- 11 published photos
Carex laevivaginata (Kukenth.) Mackenzie — Smooth-sheathed Sedge [S4] [N]; Cyperaceae
Carex lasiocarpa Ehrh. ssp. americana (Fern.) D. — Löve & Bernard Woolly-fruited Sedge [S5] [N]; Cyperaceae as Carex lasiocarpa var. americana -- 8 published photos
Carex laxiculmis Schwein. var. laxiculmis — Spreading Woodland-sedge [S5] [N]; Cyperaceae
Carex laxiflora Lam. — Loose-flowered Woodland-sedge [S5] [N]; Cyperaceae -- 20 published photos
Carex leptalea Wahlenb. ssp. leptalea — Delicate Sedge [S5] [N]; Cyperaceae -- 4 published photos
Carex longii Mackenzie — Long's Sedge [S4] [N]; Cyperaceae -- 9 published photos
Carex lucorum Willd. ex Link var. lucorum — Long-beaked Pennsylvania Sedge [S5] [N]; Cyperaceae -- 6 published photos
Carex lupulina Muhl. ex Willd. — Hop-sedge [S5] [N]; Cyperaceae -- 6 published photos
Carex lurida Wahlenb. — Sallow Sedge [S5] [N]; Cyperaceae -- 17 published photos
Carex mariscoides (Muhl.) Torrey — Cladium Twig-sedge [S5] [N]; Cyperaceae as Cladium mariscoides -- 10 published photos
Carex muhlenbergii Schkuhr ex Willd. var. enervis Boott — Muhlenberg's Sedge [S4] [N]; Cyperaceae
Carex muhlenbergii Schkuhr ex Willd. var. muhlenbergii — Muhlenberg's Sedge [S4S5] [N]; Cyperaceae as Carex muehlenbergii -- 2 published photos
Carex nigra (L.) Reichard — Black Sedge [S4] [N]; Cyperaceae
Carex paleacea Schreber ex Wahlenb. — Saltmarsh-sedge [S4] [N]; Cyperaceae -- 4 published photos
Carex pallescens L. — Pale Sedge [S5] [N]; Cyperaceae -- 4 published photos
Carex panicea L. — Millet-sedge [SNA] [I]; Cyperaceae -- 5 published photos
Carex pellita Muhl. — Broad Wooly-fruited Sedge [S5] [N]; Cyperaceae
Carex pensylvanica Lam. — Pennsylvania Sedge [S5] [N]; Cyperaceae -- 11 published photos
Carex polymorpha Muhl. — Variable Sedge [E] [S2] [N]; Cyperaceae -- 5 published photos
Carex retroflexa Muhl. ex Willd. — Reflexed Sedge [S4] [N]; Cyperaceae -- 6 published photos
Carex rosea Schkuhr ex Willd. — Big Star-sedge [S5] [N]; Cyperaceae -- 4 published photos
Carex scabrata Schwein. — Scabrous Sedge [S4S5] [N]; Cyperaceae
Carex scoparia Schkuhr ex Willd. var. scoparia — Broom Sedge [S5] [N]; Cyperaceae -- 9 published photos
Carex seorsa Howe — Swamp Prickly Sedge [S4] [N]; Cyperaceae
Carex silicea Olney — Seabeach-sedge [S4] [N]; Cyperaceae -- 8 published photos
Carex spicata Hudson — European Star-sedge [SNA] [I]; Cyperaceae
Carex stipata Muhl. ex Willd. var. stipata — Awl-fruited Sedge [S5] [N]; Cyperaceae -- 8 published photos
Carex straminea Willd. ex Schkuhr — Straw-sedge [S5] [N]; Cyperaceae -- 8 published photos
Carex striata Michaux — Walter's Sedge [E] [S1] [N]; Cyperaceae -- 8 published photos
Carex stricta Lam. — Tussock-sedge [S5] [N]; Cyperaceae -- 10 published photos
Carex swanii (Fern.) Mackenzie — Swan's Sedge [S5] [N]; Cyperaceae -- 17 published photos
Carex tenera Dewey var. tenera — Slender Straw-sedge [S5] [N]; Cyperaceae -- 5 published photos
Carex tonsa (Fern.) Bicknell var. rugosperma (Mackenzie) W.J. Crins — Sand-sedge [S5] [N]; Cyperaceae -- 22 published photos
Carex tonsa (Fern.) Bicknell var. tonsa — Stiff-leaved Sand-sedge [S4] [N]; Cyperaceae
Carex tribuloides Wahlenb. var. tribuloides — Blunt Broom-sedge [S5] [N]; Cyperaceae -- 10 published photos
Carex utriculata Boott — Beaked Sedge [S5] [N]; Cyperaceae -- 11 published photos
Carex vesicaria L. — Inflated Sedge [S5] [N]; Cyperaceae
Carex vestita Willd. — Velvet-fruited Sedge [S5] [N]; Cyperaceae -- 4 published photos
Carex virescens Muhl. ex Willd. — Ribbed Sedge [S5] [N]; Cyperaceae -- 3 published photos
Carex viridula Michaux ssp. viridula — Little Green Sedge [WL] [S1S2] [N]; Cyperaceae
Carex vulpinoidea Michaux — Fox-sedge [S5] [N]; Cyperaceae -- 13 published photos
Carpinus caroliniana Walter ssp. virginiana (Marsh.) Furlow — Ironwood [S5] [N]; Betulaceae -- 19 published photos
Carya cordiformis (Wangenh.) K. Koch — Bitternut-hickory [S4] [N]; Juglandaceae -- 24 published photos
Carya glabra (P. Miller) — Sweet Pignut [S5] [N]; Juglandaceae -- 25 published photos
Carya ovata (P. Miller) K. Koch — Shagbark-hickory [S5] [N]; Juglandaceae -- 19 published photos
Carya tomentosa (Poir. in Lam.) Nutt. — Mockernut Hickory [S4S5] [N]; Juglandaceae as Carya alba -- 19 published photos
Castanea dentata (Marsh.) Borkh. — American Chestnut [S4] [N]; Fagaceae -- 44 published photos
Castanea pumila (L.) P. Miller — Chinquapin [SNA] [I]; Fagaceae
Castanea sativa P. Miller — Sweet Chestnut [SNA] [I]; Fagaceae
Castilleja coccinea (L.) Sprengel — Scarlet Painted Cup [H] [SH] [N]; Orobanchaceae
Catalpa bignonioides Walter — Indian Bean-tree [SNA] [I]; Bignoniaceae -- 5 published photos
Ceanothus americanus L. — New Jersey Tea [S4] [N]; Rhamnaceae -- 12 published photos
Celastrus orbiculatus Thunb. — Oriental Bittersweet [invasive] [SNA] [I]; Celastraceae -- 61 published photos
Celastrus scandens L. — American Bittersweet [SC] [S3] [N]; Celastraceae -- 8 published photos
Celtis occidentalis L. — Hackberry [S4] [N]; Cannabaceae in Ulmaceae -- 24 published photos
Cenchrus longispinus (Hackel) Fern. — Common Sandbur [S5] [N]; Poaceae
Centaurea cyanus L. — Bachelor's Button [SNA] [I]; Asteraceae
Centaurea jacea L. — Brown Knapweed [SNA] [I]; Asteraceae -- 13 published photos
Centaurea nigra L. — Black Knapweed [SNA] [I]; Asteraceae
Centaurea stoebe L. ssp. micranthos (Gugler) Hayek — Spotted Knapweed [likely invasive] [SNA] [I]; Asteraceae as Centaurea stoebe ssp. micranthos -- 49 published photos
Centaurea ×moncktonii C. E. Britton [SNA] [I]; Asteraceae
Cephalanthus occidentalis L. — Buttonbush [S5] [N]; Rubiaceae -- 15 published photos
Cerastium arvense L. — Field-chickweed [S5] [N]; Caryophyllaceae
Cerastium fontanum Baumg. ssp. vulgare (Hartman) Greuter & Burdet — Mouse-ear Chickweed [SNA] [I]; Caryophyllaceae as Cerastium vulgatum, Cerastium fontanum
Cerastium pumilum W. Curtis ssp. pumilum — Dwarf Mouse-ear Chickweed [SNA] [I]; Caryophyllaceae
Cerastium tomentosum L. — Snow-in-summer [SNA] [I]; Caryophyllaceae
Ceratophyllum demersum L. — Coontail [S5] [N]; Ceratophyllaceae in -- 7 published photos
Ceratophyllum echinatum A. Gray — Forked Coontail [S4] [N]; Ceratophyllaceae in
Chamaecrista fasciculata (Michaux) Greene — Partridge-pea [S4] [N]; Fabaceae -- 9 published photos
Chamaecrista nictitans (L.) Moench ssp. nictitans var. nictitans — Wild Sensitive Plant [S4] [N]; Fabaceae -- 8 published photos
Chamaecyparis thyoides (L.) B.S.P. — Atlantic White Cedar [S5] [N]; Cupressaceae -- 54 published photos
Chamaedaphne calyculata (L.) Moench — Leatherleaf [S5] [N]; Ericaceae -- 20 published photos
Chamaepericlymenum canadense (L.) Aschers. & Graebn. — Bunchberry [S5] [N]; Cornaceae as Cornus canadensis -- 11 published photos
Chamerion angustifolium (L.) Holub ssp. circumvagum (Mosq.) Kartesz — Fireweed [S5] [N]; Onagraceae as Epilobium angustifolium -- 4 published photos
Chelidonium majus L. — Celandine [SNA] [I]; Papaveraceae -- 3 published photos
Chelone glabra L. — White Turtlehead [S4] [N]; Plantaginaceae in Scrophulariaceae -- 9 published photos
Chenopodium album L. — Pigweed, Lamb's Quarters [SNA] [I]; Amaranthaceae in Chenopodiaceae -- 17 published photos
Chenopodium berlandieri Moq. var. bushianum (Aellen) Cronq. — Country Pigweed [SNA] [I]; Amaranthaceae
Chenopodium berlandieri Moq. var. macrocalycium (Aellen) Cronq. — Seabeach Pigweed [S4] [N]; Amaranthaceae as Chenopodium berlandieri var. macrocalycium in Chenopodiaceae -- 29 published photos
Chenopodium capitatum (L.) Aschers. var. capitatum — Strawberry-blite [SNA] [I]; Amaranthaceae
Chenopodium glaucum L. var. glaucum — Oak-leaf Goosefoot [SNA] [I]; Amaranthaceae in Chenopodiaceae -- 3 published photos
Chenopodium murale L. — Sowbane [SNA] [I]; Amaranthaceae
Chenopodium pratericola Rydb. — White Pigweed [S4] [N]; Amaranthaceae
Chenopodium rubrum L. var. rubrum — Coast-blite [S5] [N]; Amaranthaceae in Chenopodiaceae -- 14 published photos
Chenopodium simplex (Torrey) Raf. — Maple-leaf Goosefoot [WL] [S3?] [N]; Amaranthaceae in Chenopodiaceae -- 7 published photos
Chenopodium urbicum L. — City-goosefoot [SNA] [I]; Amaranthaceae
Chimaphila maculata (L.) Pursh — Striped Pipsissewa [S5] [N]; Ericaceae in Pyrolaceae -- 10 published photos
Chimaphila umbellata (L.) W. Barton ssp. cisatlantica (Blake) Hultén — Pipsissewa [S5] [N]; Ericaceae as Chimaphila umbellata ssp. cisatlantica in Pyrolaceae -- 7 published photos
Chionanthus virginicus L. — Fringe-tree [SNA] [I]; Oleaceae
Chrysosplenium americanum Schwein. ex Hooker — Golden Saxifrage [S4] [N]; Saxifragaceae -- 17 published photos
Cichorium intybus L. — Chicory [SNA] [I]; Asteraceae -- 7 published photos
Cicuta bulbifera L. — Bulblet Water-hemlock [S5] [N]; Apiaceae -- 12 published photos
Cicuta maculata L. var. maculata — Water-hemlock [S5] [N]; Apiaceae -- 12 published photos
Cinna arundinacea L. — Common [S5] [N]; Poaceae -- 2 published photos
Circaea alpina L. ssp. alpina — Small Enchanter's Nightshade [S4] [N]; Onagraceae
Circaea canadensis ( L.) Hill ssp. canadensis — Enchanter's Nightshade [S4S5] [N]; Onagraceae as Circaea luteniana var. canadensis -- 11 published photos
Cirsium arvense (L.) Scop. — Canada Thistle [SNA] [I]; Asteraceae -- 11 published photos
Cirsium discolor (Muhl. ex Willd.) Sprengel — Field-thistle [S5] [N]; Asteraceae
Cirsium horridulum Michaux var. horridulum — Yellow Thistle [WL] [S2S3] [N]; Asteraceae -- 8 published photos
Cirsium muticum Michaux — Swamp-thistle [S4?] [N]; Asteraceae
Cirsium pumilum (Nutt.) Sprengel var. pumilum — Pasture-thistle [S5] [N]; Asteraceae -- 13 published photos
Cirsium vulgare (Savi) Tenore — Bull-thistle [SNA] [I]; Asteraceae -- 21 published photos
Claytonia caroliniana Michaux — Broad-leaved Spring-beauty [S4] [I]; Portulacaceae -- 4 published photos
Clematis virginiana L. — Virgin's Bower [S5] [N]; Ranunculaceae -- 11 published photos
Clethra alnifolia L. — Sweet Pepper-bush [S5] [N]; Clethraceae -- 29 published photos
Clintonia borealis (Aiton) Raf. — Bluebead-lily [S4] [N]; Liliaceae -- 16 published photos
Comandra umbellata (L.) Nutt. ssp. umbellata — Bastard-toadflax [S5] [N]; Santalaceae -- 18 published photos
Commelina communis L. — Dayflower [SNA] [I]; Commelinaceae -- 3 published photos
Comptonia peregrina (L.) Coulter — Sweet-Fern [S5] [N]; Myricaceae -- 20 published photos
Conioselinum chinense (L.) B.S.P. — Hemlock-parsley [SC] [S2?] [N?]; Apiaceae
Conium maculatum L. — Poison-hemlock [SNA] [I]; Apiaceae
Convallaria majalis L. — Lily-of-the-valley [SNA] [I]; Ruscaceae in Liliaceae -- 7 published photos
Convolvulus arvensis L. — Field-bindweed [SNA] [I]; Convolvulaceae
Coptis trifolia (L.) Salisb. — Goldthread [S5] [N]; Ranunculaceae as Coptis trifolia ssp. groenlandica -- 16 published photos
Corallorhiza maculata (Raf.) Raf. — Spotted Coral-root [S4] [N]; Orchidaceae
Corallorhiza trifida Chatelain — Pale Coral-root [S4] [N]; Orchidaceae -- 1 published photos
Corema conradii (Torrey) Torrey ex Loudon — Broom-crowberry [WL] [S3] [N]; Ericaceae in Empetraceae -- 36 published photos
Coreopsis lanceolata L. — Lanceleaf-tickseed [SNA] [I]; Asteraceae -- 5 published photos
Coreopsis rosea Nutt. — Pink Tickseed [WL] [S3] [N]; Asteraceae -- 32 published photos
Corrigiola litoralis L. ssp. litoralis — Shore-strapwort [SNA] [W]; Caryophyllaceae
Corydalis solida (L.) Clairv. — Purple Corydalis [SNA] [W]; Papaveraceae
Corylus americana Walter — American Filbert [S5] [N]; Betulaceae -- 21 published photos
Corylus cornuta Marsh. — Beaked Hazelnut [S5] [N]; Betulaceae -- 16 published photos
Cota tinctoria (L.) J. Gay — Yellow Chamomile [SNA] [I]; Asteraceae
Crassula aquatica (L.) Schoenl. — Shore Pygmy-weed [T] [S2] [N]; Crassulaceae
Crataegus coccinea L. — Scarlet Hawthorn, Red Haw [SNR] [N]; Rosaceae
Crataegus macracantha Lodd. ex Loud var. macracantha — Long-thorned Hawthorn [SNR] [N]; Rosaceae
Crataegus macrosperma Ashe — Big-seeded Hawthorn [S4] [N]; Rosaceae
Crataegus monogyna Jacq. — English Hawthorn [SNA] [I]; Rosaceae
Crataegus pruinosa (Wendl. f.) K. Koch var. pruinosa — Frosted Hawthorn [SNR] [N]; Rosaceae
Crepis capillaris (L.) Wallr. — Smooth Hawk's Beard [SNA] [I]; Asteraceae
Crocanthemum bicknellii (Fern.) Barnh. — Hoary Frostweed [S4S5] [N]; Cistaceae as Helianthemum bicknellii -- 19 published photos
Crocanthemum canadense (L.) Britton — Canadian Frostweed [S4S5] [N]; Cistaceae as Helianthemum canadense -- 36 published photos
Crocanthemum dumosum Bicknell — Bushy Frostweed [SC] [S3] [N]; Cistaceae as Helianthemum dumosum -- 17 published photos
Crocanthemum propinquum (Bicknell) Bicknell — Low Frostweed [S4] [N]; Cistaceae as Helianthemum propinquum -- 25 published photos
Crotalaria sagittalis L. — Rattlebox [S4] [N]; Fabaceae
Cuscuta cephalanthi Engelm. — Buttonbush-dodder [S?] [N]; Convolvulaceae
Cuscuta compacta Juss. ex Choisy var. compacta — Dense Dodder [S4] [N]; Convolvulaceae in Cuscutaceae
Cuscuta coryli Engelm. — Pondshore-dodder [WL] [S1S2] [N]; Convolvulaceae
Cuscuta gronovii Willd. ex J.A. Schultes var. gronovii — Love-vine [S5] [N]; Convolvulaceae in Cuscutaceae -- 18 published photos
Cuscuta indecora Choisy var. indecora — Collared Dodder [H] [SH] [N]; Convolvulaceae
Cycloloma atriplicifolium (Sprengel) Coulter — Winged Pigweed [SNA] [I]; Amaranthaceae
Cynanchum louiseae Kartesz & Gandhi — Black Swallow-wort [invasive] [SNA] [I]; Apocynaceae in Asclepiadaceae -- 14 published photos
Cyperus bipartitus Torrey — Shining Flatsedge [S5] [N]; Cyperaceae
Cyperus dentatus Torrey — Pondshore Flatsedge [S5] [N]; Cyperaceae -- 17 published photos
Cyperus diandrus Torrey — Red-edged Flatsedge [S5] [N]; Cyperaceae
Cyperus erythrorhizos Muhl. — Redroot Flatsedge [S5] [N]; Cyperaceae
Cyperus esculentus L. var. leptostachyus Boeck. — Yellow Flatsedge [S5] [N]; Cyperaceae
Cyperus filicinus Vahl — Saltpond Flatsedge [S4] [N]; Cyperaceae
Cyperus grayi Torrey — Gray's Flatsedge [S4] [N]; Cyperaceae -- 19 published photos
Cyperus houghtonii Torrey — Houghton's Flatsedge [E] [S1] [N?]; Cyperaceae
Cyperus lupulinus (Spreng.) Marcks ssp. lupulinus — Slender Sand- or Button-flatsedge [S4] [N]; Cyperaceae -- 11 published photos
Cyperus lupulinus (Spreng.) Marcks ssp. macilentus (Fern.) Marcks — Sand Flatsedge [S5] [N]; Cyperaceae -- 11 published photos
Cyperus odoratus L. — Saltmarsh-flatsedge [WL] [S3S4] [N]; Cyperaceae
Cyperus polystachyos — Texas Flatsedge [WL] [S1S2] [N]; Cyperaceae
Cyperus strigosus L. — Straw-colored Flatsedge [S5] [N]; Cyperaceae -- 17 published photos
Cypripedium acaule Aiton — Pink Lady's-slipper [S5] [N]; Orchidaceae -- 7 published photos
Cystopteris tenuis (Michaux) Desv. — MacKay's Fragile Fern [S5] [N]; Woodsiaceae in Dryopteridaceae -- 5 published photos
Cytisus scoparius (L.) Link var. scoparius — Scotch Broom [SNA] [I]; Fabaceae -- 6 published photos
Cytisus ×praecox W.J. Bean [SNA] [W]; Fabaceae
Dactylis glomerata L. — Orchard-grass [SNA] [I]; Poaceae -- 6 published photos
Danthonia compressa Austin ex Peck — Woodland Oatgrass [S5] [N]; Poaceae -- 18 published photos
Danthonia spicata (L.) Beauv. ex Roemer & J.A. — Schultes Poverty-grass [S5] [N]; Poaceae -- 6 published photos
Datura inoxia P. Miller — Downy Thorn-apple [SNA] [I]; Solanaceae
Datura stramonium L. — White Thorn-apple, White Jimson-weed [SNA] [I]; Solanaceae -- 7 published photos
Daucus carota L. — Queen Anne's Lace [SNA] [I]; Apiaceae -- 4 published photos
Decodon verticillatus (L.) Ell. — Water-willow [S5] [N]; Lythraceae -- 25 published photos
Dendrolycopodium obscurum (L.) A. Haines — Ground-pine, Princess Pine [S5] [N]; Lycopodiaceae as Lycopodium obscurum -- 19 published photos
Dennstaedtia punctilobula (Michaux) T. Moore — Hay-scented Fern [S5] [N]; Dennstaedtiaceae -- 16 published photos
Deparia acrostichoides (Swartz) M. Kato — Silvery Spleenwort [S5] [N]; Woodsiaceae in Dryopteridaceae -- 5 published photos
Deschampsia flexuosa (L.) Trin. — Common Hairgrass [S5] [N]; Poaceae -- 8 published photos
Desmodium canadense (L.) DC. — Canadian Tick-trefoil [S5] [N]; Fabaceae -- 14 published photos
Desmodium ciliare (Muhl. ex Willd.) DC. — Hairy Small-leaved Tick-trefoil [S4] [N]; Fabaceae -- 9 published photos
Desmodium marilandicum (L.) DC. — Maryland Tick-trefoil [S4] [N]; Fabaceae -- 10 published photos
Desmodium obtusum (Muhl. ex Willd.) DC. — Stiff Tick-trefoil [S4] [N]; Fabaceae
Desmodium paniculatum (L.) DC. — Panicled Tick-trefoil [S4] [N]; Fabaceae -- 6 published photos
Desmodium sessilifolium (Torrey) Torrey & A. Gray — Sessile-leaved Tick-trefoil [H] [SH] [N]; Fabaceae
Dianthus armeria L. — Deptford Pink [SNA] [I]; Caryophyllaceae -- 5 published photos
Dianthus deltoides L. — Maiden-pink [SNA] [I]; Caryophyllaceae
Dichanthelium acuminatum (Sw.) Gould & Clark ssp. columbianum (Scribn.) Freckmann & Lelong — Downy Panic-grass [S5] [N]; Poaceae as Dichanthelium columbianum
Dichanthelium acuminatum (Sw.) Gould & Clark ssp. fasciculatum (Torrey) Freckmann & Lelong — Fascicled Panic-grass [S5] [N]; Poaceae as Dichanthelium acuminatum var. fasciculatum -- 16 published photos
Dichanthelium acuminatum (Sw.) Gould & Clark ssp. implicatum (Scribn.) Freckmann & Lelong — Pondshore Panic-grass [S4] [N]; Poaceae as Dichanthelium acuminatum var. implicatum -- 8 published photos
Dichanthelium acuminatum (Sw.) Gould & Clark ssp. spretum (J.A. Schultes) Freckmann & Lelong — Smooth Panic-grass [S4] [N]; Poaceae as Dichanthelium spretum -- 4 published photos
Dichanthelium boreale (Nash) Freckmann — Northern Panic-grass [S5] [N]; Poaceae
Dichanthelium clandestinum (L.) Gould — Deer-tongue [S5] [N]; Poaceae -- 10 published photos
Dichanthelium commutatum (J.A. Schultes) Gould ssp. ashei (G. Pearson ex Ashe) Freckmann & Lelong — Changeable Panic-grass [S4] [N]; Poaceae
Dichanthelium depauperatum (Muhl.) Gould — Depauperate Panic-grass [S5] [N]; Poaceae -- 3 published photos
Dichanthelium dichotomum (L.) Gould ssp. dichotomum — Forked Panic-grass [S5] [N]; Poaceae -- 10 published photos
Dichanthelium dichotomum (L.) Gould ssp. mattamuskeetense (Ashe) Freckmann & Lelong — Mattamuskeet Panic-grass [E] [S1] [N]; Poaceae
Dichanthelium dichotomum (L.) Gould ssp. microcarpon (Muhl. ex Ell.) Freckmann & Lelong — Tiny-fruited Panic-grass [S4] [N]; Poaceae
Dichanthelium latifolium (L.) Gould & Clark — Broad-leaved Panic-grass [S5] [N]; Poaceae -- 5 published photos
Dichanthelium linearifolium (Scribner) Gould — Linear-leaved Panic-grass [S5] [N]; Poaceae -- 4 published photos
Dichanthelium oligosanthes (J.A. Schultes) Gould ssp. scribnerianum (Nash) Freckmann & Lelong — Scribner's Panic-grass [S5] [N]; Poaceae as Dichanthelium oligosanthes var. scribnerianum -- 8 published photos
Dichanthelium sphaerocarpon (Ell.) Gould — Round-fruited Panic-grass [S5] [N]; Poaceae -- 9 published photos
Dichanthelium wrightianum (Scribner) Freckmann — Wright's Panic-grass [SC] [S3] [N]; Poaceae -- 2 published photos
Diervilla lonicera P. Miller — Bush-honeysuckle [S5] [N]; Caprifoliaceae -- 14 published photos
Digitaria filiformis (L.) Koeler — Slender Crab-grass [S5] [N]; Poaceae
Digitaria ischaemum (Schreber) Muhl. — Smooth Crab-grass [SNA] [I]; Poaceae -- 2 published photos
Digitaria sanguinalis (L.) Scop. — Large Crab-grass [SNA] [I]; Poaceae -- 11 published photos
Diodia teres Walter var. teres — Buttonweed [SNA] [I]; Rubiaceae -- 15 published photos
Dioscorea villosa L. — Wild Yam [WL] [SNR] [N]; Dioscoreaceae
Diphasiastrum digitatum (Dill. ex A. Braun) Holub — Southern Ground-cedar [S5] [N]; Lycopodiaceae -- 18 published photos
Diphasiastrum tristachyum (Pursh) Holub — Slender Ground-cedar [S5] [N]; Lycopodiaceae -- 3 published photos
Dirca palustris L. — Leatherwood [S4] [I]; Thymelaeaceae -- 5 published photos
Distichlis spicata (L.) Greene — Saltmarsh Spike-grass [S5] [N]; Poaceae -- 13 published photos
Doellingeria umbellata (P. Mill.) Nees var. umbellata — Tall Flat-topped White Aster [S5] [N]; Asteraceae as Aster umbellatus -- 14 published photos
Draba verna L. — Longpod Whitlow-grass [SNA] [I]; Brassicaceae -- 21 published photos
Dracocephalum parviflorum Nutt. — American Dragonhead [SNA] [I]; Lamiaceae
Drosera filiformis Raf. var. filiformis — Thread-leaf Sundew [S4] [N]; Droseraceae -- 26 published photos
Drosera intermedia Hayne — Spatulate-leaved Sundew [S4S5] [N]; Droseraceae -- 14 published photos
Drosera rotundifolia L. — Round-leaved Sundew [S4S5] [N]; Droseraceae -- 23 published photos
Dryopteris campyloptera (Kunze) Clarkson — Mountain Wood-fern [WL] [S3?] [I?]; Dryopteridaceae
Dryopteris carthusiana (Vill.) H.P. Fuchs — Spinulose Wood-fern [S4] [N]; Dryopteridaceae -- 17 published photos
Dryopteris cristata (L.) A. Gray — Crested Wood-fern [S4] [N]; Dryopteridaceae -- 17 published photos
Dryopteris intermedia (Muhl. ex Willd.) A. Gray — Intermediate Wood-fern [S5] [N]; Dryopteridaceae -- 20 published photos
Dryopteris marginalis (L.) A. Gray — Marginal Wood-fern [S5] [N]; Dryopteridaceae -- 21 published photos
Dryopteris ×boottii (Tuckerman) Underw. — Boott's Wood-fern [SNR] [N]; Dryopteridaceae as Dryopteris x boottii
Dryopteris ×slossoniae Wherry ex Lellinger — Slosson's Wood-fern [SNR] [N]; Dryopteridaceae as Dryopteris x slossonae
Dulichium arundinaceum (L.) Britton var. arundinaceum — Threeway Sedge [S5] [N]; Cyperaceae -- 17 published photos
Dysphania ambrosioides (L.) Mosyakin & Clemants — Wormseed [SNA] [I]; Amaranthaceae as Chenopodium ambrosioides in Chenopodiaceae -- 14 published photos
Dysphania botrys (L.) Mosyakin & Clemants — Jerusalem Oak [SNA] [I]; Amaranthaceae
Echinochloa crus-galli (L.) Beauv. — Barnyard-grass [SNA] [I]; Poaceae -- 11 published photos
Echinochloa muricata (Beauv.) Fern. var. muricata — Cockspur-grass, Barnyard-grass [S5] [N]; Poaceae
Echinocystis lobata (Michaux) Torrey & A. Gray — Wild Balsam-apple [S4] [N]; Cucurbitaceae -- 8 published photos
Echium vulgare L. — Viper's Bugloss [SNA] [I]; Boraginaceae -- 3 published photos
Egeria densa Planchon — Brazilian Water-weed [likely invasive] [SNA] [I]; Hydrocharitaceae -- 3 published photos
Elaeagnus angustifolia L. — Russian Olive [SNA] [I]; Elaeagnaceae -- 4 published photos
Elaeagnus pungens Thunb. — Japanese Oleaster [SNA] [W]; Elaeagnaceae
Elaeagnus umbellata Thunb. var. parvifolia (Royle) Schneid. — Autumn-olive [invasive] [SNA] [I]; Elaeagnaceae -- 27 published photos
Elatine americana (Pursh) Arnott — American Waterwort [E] [S1] [N]; Elatinaceae in
Elatine minima (Nutt.) Fischer & C.A. Meyer — Lesser Waterwort [S4] [N]; Elatinaceae in
Eleocharis acicularis (L.) Roemer & Schultes — Little Spike-rush [S5] [N]; Cyperaceae -- 28 published photos
Eleocharis elliptica Kunth var. elliptica — Orange-fruited Spike-rush [S5] [N]; Cyperaceae -- 3 published photos
Eleocharis flavescens (Poir.) Urban var. olivacea — Olive Spike-rush [S5] [N]; Cyperaceae as Eleocharis flavescens var. olivacea -- 17 published photos
Eleocharis melanocarpa Torrey — Black-fruited Spike-rush [WL] [S3] [N]; Cyperaceae -- 35 published photos
Eleocharis obtusa (Willd.) J.A. Schultes var. obtusa — Soft-stemmed Spike-rush [S5] [N]; Cyperaceae -- 37 published photos
Eleocharis palustris (L.) Roemer & Schultes — Creeping Spike-rush [S5] [N]; Cyperaceae -- 7 published photos
Eleocharis parvula (Roemer & Schultes) Link ex Bluff, Nees & Schauer — Saltpond- or Dwarf Spike-rush [S4] [N]; Cyperaceae -- 7 published photos
Eleocharis robbinsii Oakes — Robbins' Spike-rush [S5] [N]; Cyperaceae -- 39 published photos
Eleocharis rostellata (Torrey) Torrey — Beaked or Saltmarsh Spike-rush [WL] [S2?] [N]; Cyperaceae -- 20 published photos
Eleocharis tenuis (Willd.) J.A. Schultes var. pseudoptera (Weatherby ex Svens.) Svens. [H] [SH] [N]; Cyperaceae
Eleocharis tenuis (Willd.) J.A. Schultes var. tenuis var. tenuis — Slender Spike-rush [S5] [N]; Cyperaceae -- 1 published photos
Eleocharis tuberculosa (Michaux) Roemer & Schultes — Tubercled Spike-rush [S4] [N]; Cyperaceae -- 14 published photos
Eleocharis uniglumis (Link) Schultes — One-glumed Spike-rush [S4] [N]; Cyperaceae -- 16 published photos
Eleusine indica (L.) Gaertner — Goose-grass [SNA] [I]; Poaceae -- 7 published photos
Eleusine walterii (Pursh) Heller — Walter's Cockspur [S4] [N]; Poaceae as Echinochloa walterii -- 13 published photos
Elodea nuttallii (Planchon) St. John — Nuttall's Water-weed [S5] [N]; Hydrocharitaceae
Elymus hystrix L. — Bottlebrush-grass [S5] [N]; Poaceae as Hystrix patula -- 8 published photos
Elymus repens (L.) Gould — Quack-grass [SNA] [I]; Poaceae as Elytrigia repens
Elymus villosus Muhl. ex Willd. — Hairy Wild Rye [E] [S1] [N]; Poaceae
Elymus virginicus L. var. halophilus (Bicknell) Wieg. — Saltmarsh Wild Rye [S4] [N]; Poaceae as Elymus virginicus var. halophilus -- 11 published photos
Elymus virginicus L. var. virginicus — Virginia Wild Rye [S5] [N]; Poaceae -- 13 published photos
Epifagus virginiana (L.) W.P.C. Barton — Beech-drops [S5] [N]; Orobanchaceae -- 13 published photos
Epigaea repens L. — Mayflower [S5] [N]; Ericaceae -- 35 published photos
Epilobium ciliatum Raf. var. ciliatum — American Willow-herb [S5] [N]; Onagraceae -- 13 published photos
Epilobium coloratum Biehler — Eastern Willow-herb [S5] [N]; Onagraceae -- 3 published photos
Epilobium hirsutum L. — Hairy Willow-herb [likely invasive] [SNA] [I]; Onagraceae
Epilobium leptophyllum Raf. — Narrow-leaved Willow-herb [S4S5] [N]; Onagraceae -- 2 published photos
Epilobium palustre L. — Marsh Willow-herb [S4S5] [N]; Onagraceae
Epilobium strictum Muhl. ex Sprengel — Northeastern Willow-herb [S4] [N]; Onagraceae
Equisetum arvense L. — Field-horsetail [S5] [N]; Equisetaceae -- 19 published photos
Equisetum fluviatile L. — River-horsetail [S5] [N]; Equisetaceae -- 20 published photos
Equisetum hyemale L. ssp. affine (Engelm.) Calder & Taylor — Scouring Rush [S5] [N]; Equisetaceae -- 10 published photos
Equisetum sylvaticum L. — Woodland-horsetail [S4] [N]; Equisetaceae -- 3 published photos
Eragrostis capillaris (L.) Nees — Lace-grass [WL] [SNA] [N]; Poaceae
Eragrostis curvula (Schrader) Nees — Weeping Lovegrass [SNA] [I]; Poaceae -- 3 published photos
Eragrostis minor Host — Little Lovegrass [SNA] [I]; Poaceae
Eragrostis pectinacea (Michaux) Nees var. pectinacea — Tufted Lovegrass [S5] [N]; Poaceae -- 11 published photos
Eragrostis spectabilis (Pursh) Steudel — Purple Lovegrass [S5] [N]; Poaceae -- 14 published photos
Erechtites hieraciifolius (L.) Raf. ex DC. var. hieracifolius — Pilewort, Fireweed [S5] [N]; Asteraceae as Erechtites hieracifolius -- 23 published photos
Erechtites hieraciifolius (L.) Raf. ex DC. var. megalocarpus (Fern.) Cronq. — Seaside Pilewort [WL] [S2S3] [N]; Asteraceae as Erechtites hieracifolius var. megalocarpus -- 1 published photos
Erigeron annuus (L.) Pers. — Daisy-fleabane [S5] [N]; Asteraceae -- 8 published photos
Erigeron canadensis L. — Horseweed, Hogweed, Butterweed [S5] [N]; Asteraceae as Conyza canadensis -- 25 published photos
Erigeron philadelphicus L. var. philadelphicus — Philadelphia Fleabane [S5] [N]; Asteraceae -- 5 published photos
Erigeron pulchellus Michaux var. pulchellus — Robin's Plantain [S5] [N]; Asteraceae
Erigeron strigosus Muhl. ex Willd. var. strigosus Torrey & A. Gray) — Rough Fleabane, Lesser Daisy-fleabane [S5] [N]; Asteraceae as Erigeron strigosus, Erigeron strigosus var. discoideus
Eriocaulon aquaticum (Hill) Druce — Pipewort [S5] [N]; Eriocaulaceae -- 27 published photos
Eriocaulon parkeri Robinson — Parker's Pipewort [E] [S1] [N]; Eriocaulaceae
Eriophorum tenellum Nutt. — Rough Cotton-grass [S5] [N]; Cyperaceae
Eriophorum vaginatum L. — Hare's-tail Cotton-grass [S5] [N]; Cyperaceae
Eriophorum virginicum L. — Tawny Cotton-grass [S5] [N]; Cyperaceae -- 12 published photos
Erysimum cheiranthoides L. — Wormseed-mustard [SNA] [I]; Brassicaceae -- 7 published photos
Erythronium americanum Ker-Gawler ssp. americanum — Trout-lily [S5] [N]; Liliaceae -- 17 published photos
Eubotrys racemosa (L.) Nutt. — Swamp-sweetbells [S4] [N]; Ericaceae as Leucothoe racemosa -- 22 published photos
Euonymus alatus (Thunb.) Sieb. — Winged Euonymus [invasive] [SNA] [I]; Celastraceae as Euonymus alata -- 16 published photos
Euonymus europaea L. — European Spindle-tree [SNA] [I]; Celastraceae -- 9 published photos
Euonymus fortunei (Turcz.) Handel-Maz. var. radicans (Sieb. ex Miq.) Rehder — Winter-creeper [SNA] [I]; Celastraceae -- 7 published photos
Euonymus fortunei (Turcz.) Handel-Maz. var. vegeta (Rehder) Rehder — Big-leaved Winter-creeper [SNA] [I]; Celastraceae -- 7 published photos
Eupatorium hyssopifolium L. — Hyssop-leaved Boneset [S4?] [N]; Asteraceae -- 13 published photos
Eupatorium novae-angliae (Fern.) V. Sullivan ex A. Haines & Sorrie — New England-boneset [E] [S1] [N]; Asteraceae -- 8 published photos
Eupatorium perfoliatum L. — Boneset [S5] [N]; Asteraceae -- 26 published photos
Eupatorium pilosum Walter — Rough Boneset [S5] [N]; Asteraceae -- 25 published photos
Eupatorium pubescens Muhl. ex Willd. — Hairy Boneset [S4?] [N]; Asteraceae as Eupatorium rotundifolium var. ovatum -- 3 published photos
Eupatorium serotinum Michaux — Late Boneset [SNA] [W]; Asteraceae
Eupatorium sessilifolium L. — Upland Boneset [S4] [N]; Asteraceae
Euphorbia cyparissias L. — Cypress-spurge [likely invasive] [SNA] [I]; Euphorbiaceae -- 10 published photos
Euphorbia esula L. — Leafy Spurge [invasive] [SNA] [I]; Euphorbiaceae -- 7 published photos
Euphorbia maculata L. — Milk-purslane [S5] [N]; Euphorbiaceae -- 17 published photos
Euphorbia polygonifolia L. — Seaside-spurge [S4] [N]; Euphorbiaceae -- 16 published photos
Eurybia divaricata (L.) Nesom — White Wood-aster [S5] [N]; Asteraceae as Aster divaricatus -- 10 published photos
Eurybia macrophylla (L.) Cass. — Big-leaved Aster [S5] [N]; Asteraceae as Aster macrophyllus -- 16 published photos
Eurybia radula (Aiton) Nesom — Rough Aster [WL] [S1S2] [N]; Asteraceae
Eurybia spectabilis (Aiton) Nesom — Showy Aster [S4] [N]; Asteraceae as Aster spectabilis -- 32 published photos
Eurybia ×herveyi (A. Gray) Nesom — Cartpath-aster [SNR] [N]; Asteraceae
Euthamia caroliniana (L.) Greene ex Porter & Britton — Slender-leaved Flat-topped Goldenrod [S5] [N]; Asteraceae -- 17 published photos
Euthamia graminifolia (L.) Nutt. — Grass-leaf Flat-topped Goldenrod, Common Flat-topp [S5] [N]; Asteraceae -- 9 published photos
Eutrochium dubium (Willd. ex Poir.) E.E. Lamont — Atlantic Joe-Pye-weed [S5] [N]; Asteraceae as Eupatorium dubium -- 22 published photos
Eutrochium fistulosum (Barratt) E.E. Lamont — Hollow-stemmed Joe-Pye-weed [S5] [N]; Asteraceae as Eupatorium fistulosum -- 17 published photos
Eutrochium purpureum (L.) E.E. Lamont var. purpureum — Sweet Joe-Pye-weed [S4] [N]; Asteraceae as Eupatorium purpureum -- 9 published photos
Fagopyrum esculentum Moench — Buckwheat [SNA] [I]; Polygonaceae
Fagus grandifolia Ehrh. — American Beech [S5] [N]; Fagaceae -- 35 published photos
Fagus sylvatica L. — European Beech [SNA] [I]; Fagaceae -- 6 published photos
Fallopia cilinodis (Michaux) Holub — Fringed Bindweed [S5] [N]; Polygonaceae
Fallopia convolvulus (L.) A. Löve — Black Bindweed [SNA] [I]; Polygonaceae as Polygonum convolvulus -- 1 published photos
Fallopia cristata (Engelm. & A. Gray) Holub — Winged Bindweed [S5] [N]; Polygonaceae as Polygonum cristatum -- 9 published photos
Fallopia japonica (Houtt.) R. Decr. — Japanese Knotweed [invasive] [SNA] [I]; Polygonaceae as Polygonum cuspidatum -- 25 published photos
Fallopia sachalinensis (F.S. Petrop. ex Maxim.) R. Decr. — Giant Knotweed [SNA] [I]; Polygonaceae
Fallopia scandens (L.) Holub — Climbing False Buckwheat, Bindweed [S5] [N]; Polygonaceae as Polygonum scandens -- 17 published photos
Fallopia ×bohemica (Chrtek & Chrtková) J.P. Bailey [SNA] [I]; Polygonaceae as Polygonum x bohemicum -- 13 published photos
Festuca filiformis Pourret — Hair-fescue [likely invasive] [SNA] [I]; Poaceae -- 7 published photos
Festuca ovina L. — Sheep-fescue [SNA] [I]; Poaceae
Festuca rubra L. ssp. commutata Gaudin — Red Fescue [SNA] [I]; Poaceae -- 2 published photos
Festuca rubra L. ssp. pruinosa (Hack.) Piper — Coastal Red Fescue [S4] [N]; Poaceae -- 2 published photos
Festuca rubra L. ssp. rubra — Red Fescue [SNA] [I]; Poaceae -- 2 published photos
Festuca subverticillata (Pers.) Alexeev — Nodding Fescue [S4S5] [N]; Poaceae
Festuca trachyphylla (Hackel) Krajina — Hard Fescue [SNA] [I]; Poaceae
Ficus carica L. — Fig [SNA] [W]; Moraceae
Filago vulgaris Lam. — Common Cotton-rose [SNA] [?]; Asteraceae
Fimbristylis autumnalis (L.) Roemer & Schultes — Autumn Fimbry [S5] [N]; Cyperaceae -- 11 published photos
Fragaria vesca L. ssp. vesca — European Strawberry [SNA] [I]; Rosaceae -- 3 published photos
Fragaria virginiana Duchesne ssp. virginiana — Wild Strawberry, Thick-leaved Wild Strawberry [S5] [N]; Rosaceae -- 10 published photos
Fragaria ×ananasa Duchesne — Garden Strawberry [SNA] [I]; Rosaceae as Fragaria x ananasa -- 3 published photos
Frangula alnus P. Miller — Glossy Alder-buckthorn [invasive] [SNA] [I]; Rhamnaceae as Rhamnus frangula -- 25 published photos
Fraxinus americana L. — White Ash [S5] [N]; Oleaceae -- 35 published photos
Fraxinus excelsior L. — Common Ash [SNA] [I]; Oleaceae
Fraxinus nigra Marshall — Black Ash [S4S5] [N]; Oleaceae -- 20 published photos
Fraxinus pennsylvanica Marshall — Green Ash [S4S5] [N]; Oleaceae -- 18 published photos
Froelichia gracilis (Hooker) Moq. — Slender Cottonweed [SNA] [I]; Amaranthaceae -- 17 published photos
Fuirena pumila (Torrey) Sprengel — Annual Umbrella-sedge [WL] [S3] [N]; Cyperaceae -- 27 published photos
Fumaria officinalis L. ssp. officinalis — Fumitory [SNA] [I]; Papaveraceae in Fumariaceae -- 5 published photos
Gaillardia aristata Pursh — Perennial Gaillardia [SNA] [W]; Asteraceae
Galeopsis bifida Boenn. — Cleft Hemp-nettle [SNA] [I]; Lamiaceae -- 8 published photos
Galinsoga parviflora Cav. — Quickweed [SNA] [I]; Asteraceae -- 2 published photos
Galinsoga quadriradiata Ruiz & Pavón — Hairy Quickweed [SNA] [I]; Asteraceae -- 8 published photos
Galium aparine L. — Cleavers [S5] [N]; Rubiaceae -- 5 published photos
Galium asprellum Michaux — Rough Bedstraw [S5] [N]; Rubiaceae -- 3 published photos
Galium brevipes Fern. & Wiegand — Short-stalked Bedstraw [SNR] [?]; Rubiaceae -- 4 published photos
Galium circaezans Michaux var. circaezans — Wild Licorice, Forest-bedstraw [S4] [N]; Rubiaceae -- 12 published photos
Galium mollugo L. — Field-madder [SNA] [I]; Rubiaceae -- 17 published photos
Galium obtusum Bigelow ssp. obtusum — Blunt-leaved Marsh-bedstraw [S5] [N]; Rubiaceae -- 4 published photos
Galium palustre L. — Marsh-bedstraw [S5] [N]; Rubiaceae -- 4 published photos
Galium pilosum Aiton var. pilosum — Hairy Bedstraw [S4?] [N]; Rubiaceae -- 14 published photos
Galium sylvaticum L. — Scotch Mist [SNA] [W]; Rubiaceae
Galium tinctorium (L.) Scop. var. tinctorium — Clayton's Marsh-bedstraw [S5] [N]; Rubiaceae -- 18 published photos
Galium triflorum Michaux — Sweet-scented Bedstraw [S5] [N]; Rubiaceae -- 8 published photos
Galium verum L. ssp. verum — Yellow Bedstraw, Our Lady's Bedstraw [SNA] [I]; Rubiaceae
Gamochaeta purpurea (L.) Cabrera — Purple Cudweed [E] [S1] [N]; Asteraceae
Gaultheria hispidula (L.) Muhl. ex Bigelow — Creeping Snowberry [S4] [N]; Ericaceae -- 9 published photos
Gaultheria procumbens L. — Wintergreen [S5] [N]; Ericaceae -- 24 published photos
Gaylussacia baccata (Wangenh.) K. Koch — Black Huckleberry [S5] [N]; Ericaceae -- 27 published photos
Gaylussacia bigeloviana (Fern.) Sorrie & Weakley — Dwarf Huckleberry [S4] [N]; Ericaceae as Gaylussacia dumosa var. bigelowiana -- 9 published photos
Gaylussacia frondosa (L.) Torrey & A. Gray ex Torrey — Dangleberry [S4S5] [N]; Ericaceae -- 18 published photos
Genista tinctoria L. — Dyer's Greenweed [SNA] [I]; Fabaceae -- 2 published photos
Gentiana andrewsii Griseb. var. andrewsii — Andrews's Bottle-gentian [E] [S1] [N]; Gentianaceae
Gentianopsis crinita (Froel.) Ma — Fringed Gentian [S4] [N]; Gentianaceae -- 4 published photos
Geranium carolinianum L. — Carolina Crane's Bill [S4] [N]; Geraniaceae -- 3 published photos
Geranium maculatum L. — Wild Geranium [S5] [N]; Geraniaceae -- 13 published photos
Geranium molle L. — Dove's Foot Crane's Bill [SNA] [I]; Geraniaceae
Geranium pusillum L. — Small Crane's Bill [SNA] [I]; Geraniaceae
Geranium robertianum L. — Herb-Robert [S4S5] [N]; Geraniaceae -- 12 published photos
Geum canadense Jacq. var. canadense — White Avens [S5] [N]; Rosaceae -- 12 published photos
Geum fragarioides (Michaux) Smedmark — Barren Strawberry [SC] [S3] [I]; Rosaceae
Glaucium flavum Crantz — Sea-poppy [invasive] [SNA] [I]; Papaveraceae -- 5 published photos
Glebionis segetum (L.) Fourr. — Corn-marigold [SNA] [W]; Asteraceae
Glechoma hederacea L. — Gill-over-the-ground [SNA] [I]; Lamiaceae -- 12 published photos
Gleditsia triacanthos L. — Honey-locust [SNA] [I]; Fabaceae -- 12 published photos
Glyceria acutiflora Torrey — Sharp-scaled Mannagrass [S4?] [N]; Poaceae
Glyceria canadensis (Michaux) Trin. — Mannagrass [S5] [N]; Poaceae -- 9 published photos
Glyceria grandis S. Watson var. grandis — Tall Mannagrass [S5] [N]; Poaceae
Glyceria obtusa (Muhl.) Trin. — Coastal Mannagrass [S4S5] [N]; Poaceae -- 11 published photos
Glyceria septentrionalis A.S. Hitchc. var. septentrionalis — Eastern Float-grass [S5] [N]; Poaceae
Glyceria striata (Lam.) A.S. Hitchc. — Fowl Mannagrass [S5] [N]; Poaceae -- 6 published photos
Gnaphalium uliginosum L. — Low Cudweed [S5] [N]; Asteraceae -- 5 published photos
Goodyera pubescens (Willd.) R. Br. — Downy Rattlesnake-plantain [S4] [N]; Orchidaceae -- 13 published photos
Goodyera tesselata Lodd. — Checkered Rattlesnake-plantain [S4] [N]; Orchidaceae -- 17 published photos
Gratiola aurea Pursh — Golden Pert [S5] [N]; Plantaginaceae in Scrophulariaceae -- 29 published photos
Gratiola neglecta Torrey — Mud Hedge-hyssop [S4] [N]; Plantaginaceae in Scrophulariaceae -- 7 published photos
Hamamelis virginiana L. — Witch-hazel [S5] [N]; Hamamelidaceae -- 33 published photos
Helenium autumnale L. — Common Sneezeweed [WL] [I]; Asteraceae
Helenium flexuosum Raf. — Purple-headed Sneezeweed [SNA] [I]; Asteraceae -- 6 published photos
Helianthus annuus L. — Common Sunflower [SNA] [I]; Asteraceae -- 3 published photos
Helianthus divaricatus L. — Divaricate Sunflower [S4] [N]; Asteraceae -- 14 published photos
Helianthus grosseserratus Martens — Saw-toothed Sunflower [SNA] [I]; Asteraceae
Helianthus strumosus L. — Harsh Sunflower [S4] [N]; Asteraceae
Helianthus tuberosus L. — Jerusalem Artichoke [SNA] [I]; Asteraceae -- 3 published photos
Helianthus ×laetiflorus Pers. — Showy Sunflower [SNA] [I]; Asteraceae
Hemerocallis fulva (L.) L. — Orange Day-lily [SNA] [I]; Hemerocallidaceae in Liliaceae -- 8 published photos
Hemerocallis lilioasphodelus L. — Yellow Day-lily [SNA] [I]; Hemerocallidaceae
Heracleum maximum Bartram — Cow-parsnip [S5] [N]; Apiaceae -- 36 published photos
Hesperis matronalis L. — Dame's Rocket [invasive] [SNA] [I]; Brassicaceae -- 13 published photos
Hibiscus moscheutos L. ssp. moscheutos — Rose-mallow [S4] [N]; Malvaceae -- 15 published photos
Hieracium aurantiacum L. — Orange Hawkweed [SNA] [I]; Asteraceae -- 6 published photos
Hieracium flagellare Willd. — Whip-hawkweed [SNA] [I]; Asteraceae -- 6 published photos
Hieracium gronovii L. — Hairy Hawkweed [S4] [N]; Asteraceae -- 15 published photos
Hieracium lachenalii K.C. Gmelin — European Hawkweed [SNA] [I]; Asteraceae -- 5 published photos
Hieracium paniculatum L. — Panicled Hawkweed [S5] [N]; Asteraceae -- 14 published photos
Hieracium pilosella L. — Mouse-ear Hawkweed [SNA] [I]; Asteraceae -- 5 published photos
Hieracium piloselloides Vill. — Smooth Hawkweed [SNA] [I]; Asteraceae -- 3 published photos
Hieracium scabrum Michaux — Rough Hawkweed [S5] [N]; Asteraceae -- 14 published photos
Hieracium umbellatum L. — Canada Hawkweed [S5] [N]; Asteraceae
Hieracium venosum L. — Rattlesnake Weed [N]; Asteraceae -- 4 published photos
Hieracium ×marianum Willd. — Maryland Hawkweed [SNR] [N]; Asteraceae
Holcus lanatus L. — Velvet-grass [SNA] [I]; Poaceae -- 12 published photos
Honckenya peploides (L.) Ehrh. ssp. robusta (Fern.) Hultén — Seabeach sandwort [S4] [N]; Caryophyllaceae as Honckenya peploides ssp. robusta -- 20 published photos
Hordeum jubatum L. ssp. jubatum — Foxtail-barley [SNA] [I]; Poaceae
Hordeum vulgare L. — Barley, Six-row Barley [SNA] [I]; Poaceae
Hottonia inflata Ell. — Featherfoil [WL] [S3] [N]; Primulaceae -- 7 published photos
Houstonia caerulea L. — Bluets, Quaker Ladies, Innocence [S5] [N]; Rubiaceae -- 26 published photos
Houstonia longifolia Gaertner — Long-leaved Bluets [E] [S1] [N]; Rubiaceae
Hudsonia ericoides L. — Golden Heather [S4] [N]; Cistaceae -- 32 published photos
Hudsonia ericoides L. × H. tomentosa Nutt. [SNR] [N]; Cistaceae
Hudsonia tomentosa Nutt. — Beach-heather, Hudsonia, Poverty-grass [S4] [N]; Cistaceae -- 20 published photos
Humulus lupulus L. var. lupulus — Common Hops [SNA] [I]; Cannabaceae -- 4 published photos
Huperzia lucidula (Michaux) Trev. — Shining Fir-moss [S5] [N]; Huperziaceae in Lycopodiaceae -- 11 published photos
Hydrastis canadensis L. — Golden Seal [E] [S1] [I]; Ranunculaceae
Hydrilla verticillata (L. f.) Royle — hydrilla [likely invasive] [SNA] [I]; Hydrocharitaceae
Hydrocotyle americana L. — Swamp-pennywort [S5] [N]; Apiaceae -- 13 published photos
Hydrocotyle umbellata L. — Water-pennywort [S4] [N]; Apiaceae -- 7 published photos
Hylodesmum glutinosum (Muhl. ex Willd.) H. Ohashi & R.R. Mill — Cluster-leaf Tick-trefoil [S4] [N]; Fabaceae as Desmodium glutinosum -- 5 published photos
Hylodesmum nudiflorum (L.) H. Ohashi & R.R. Mill — Naked Tick-trefoil [S5] [N]; Fabaceae as Desmodium nudiflorum -- 5 published photos
Hylotelephium telephium (L.) H. Ohba ssp. telephium — Live-forever [SNA] [I]; Crassulaceae as Sedum telephium -- 1 published photos
Hypericum boreale (Britton) Bicknell — Northern Dwarf St. John's-wort [S5] [N]; Hypericaceae in Clusiaceae
Hypericum canadense L. — Canadian St. John's-wort [S5] [N]; Hypericaceae in Clusiaceae -- 11 published photos
Hypericum ellipticum Hooker — Pale St. John's-wort [S5] [N]; Hypericaceae in Clusiaceae -- 16 published photos
Hypericum gentianoides (L.) B.S.P. — Orange Grass [S5] [N]; Hypericaceae in Clusiaceae -- 18 published photos
Hypericum majus (A. Gray) Britton — Larger Canadian St. John's-wort [S4] [N]; Hypericaceae
Hypericum mutilum L. — Dwarf St. John's-wort [S5] [N]; Hypericaceae in Clusiaceae
Hypericum perforatum L. — Common St. John's-wort [SNA] [I]; Hypericaceae in Clusiaceae -- 9 published photos
Hypericum punctatum Lam. — Spotted St. John's-wort [S5] [N]; Hypericaceae in Clusiaceae -- 12 published photos
Hypericum ×dissimulatum Bicknell — Bicknell's St. John's-wort [SNR] [N]; Hypericaceae
Hypochaeris radicata L. — Spotted Cat's Ear [SNA] [I]; Asteraceae -- 32 published photos
Hypopitys monotropa Crantz — Pinesap [S5] [N]; Ericaceae as Monotropa hypopitys in Monotropaceae -- 16 published photos
Hypoxis hirsuta (L.) Cov. — Yellow Star-grass [S4S5] [N]; Hypoxidaceae in Liliaceae -- 10 published photos
Ilex glabra (L.) A. Gray — Inkberry [S4] [N]; Aquifoliaceae -- 19 published photos
Ilex laevigata (Pursh) A. Gray — Smooth Winterberry [S4] [N]; Aquifoliaceae
Ilex mucronata (L.) M. Powell, Savol., & S. Andrews — Mountain-holly [S5] [N]; Aquifoliaceae as Nemopanthus mucronatus -- 39 published photos
Ilex opaca Aiton var. opaca — American Holly [N]; Aquifoliaceae -- 38 published photos
Ilex verticillata (L.) A. Gray — Winterberry [S5] [N]; Aquifoliaceae -- 28 published photos
Impatiens capensis Meerb. — Orange Jewelweed [S5] [N]; Balsaminaceae -- 11 published photos
Inula helenium L. [SNA] [I]; Asteraceae
Ionactis linariifolia (L.) Greene — Stiff Aster [S5] [N]; Asteraceae as -- 23 published photos
Ipomoea pandurata (L.) G.F.W. Meyer — Wild Potato-vine [SNA] [I]; Convolvulaceae
Ipomoea purpurea (L.) Roth — Common Morning-glory [SNA] [I]; Convolvulaceae
Iris prismatica Pursh — Slender Blue Flag [S4] [N]; Iridaceae
Iris sibirica L. — Siberian Iris [SNA] [I]; Iridaceae -- 2 published photos
Iris versicolor L. — Northern Blue Flag [S5] [N]; Iridaceae -- 30 published photos
Isoetes acadiensis Kott — Acadian Quillwort [E] [S1] [N]; Isoetaceae
Isoetes echinospora Dur. ssp. muricata (Dur.) Löve & Löve — Spiny-spored Quillwort [S5] [N]; Isoetaceae in
Isoetes engelmannii A. Br. — Engelmann's Quillwort [S4] [N]; Isoetaceae
Isoetes tuckermanii A. Br. ex Engelm. — Tuckerman's Quillwort [S4?] [N]; Isoetaceae
Isotria verticillata (Willd.) Raf. — Large Whorled Pogonia [WL] [S3S4] [N]; Orchidaceae -- 9 published photos
Iva frutescens (Bartlett) R.C. Jackson — Hightide-bush [S4] [N]; Asteraceae as Iva frutescens ssp. oraria -- 19 published photos
Jasione montana L. — Sheep's Bit [SNA] [I]; Campanulaceae -- 20 published photos
Juglans ailanthifolia Carr. — Japanese Walnut [SNA] [I]; Juglandaceae
Juglans cinerea L. — Butternut [WL] [S4?] [N]; Juglandaceae -- 10 published photos
Juglans nigra L. — Black Walnut [SNA] [I]; Juglandaceae -- 9 published photos
Juncus acuminatus Michaux — Sharp-fruited Rush [S5] [N]; Juncaceae
Juncus anthelatus (Wieg.) R.E. Brooks — Wiegand's Rush [SNR] [N]; Juncaceae
Juncus arcticus Willd. var. balticus (Willd.) Trautv. — Brackish Rush [S4] [N]; Juncaceae
Juncus articulatus L. — Jointed Rush [S5] [N]; Juncaceae
Juncus brachycarpus Engelm. — Short-fruited Rush [SNA] [W]; Juncaceae
Juncus bufonius L. — Toad-rush [S5] [N]; Juncaceae -- 3 published photos
Juncus canadensis Gay ex LaHarpe — Marsh- or Canada Rush [S5] [N]; Juncaceae -- 21 published photos
Juncus dichotomus Ell. — Forked Rush [S4] [N]; Juncaceae
Juncus effusus L. ssp. solutus (Fern. & Wieg.) — Hämet-Ahti Soft Rush [S5] [N]; Juncaceae -- 12 published photos
Juncus gerardii Loisel. — Saltmarsh-rush [S5] [N]; Juncaceae -- 7 published photos
Juncus greenei Oakes & Tuckerman — Greene's Rush [S5] [N]; Juncaceae -- 12 published photos
Juncus marginatus Rostk. — Grass-leaf rush [S5] [N]; Juncaceae -- 7 published photos
Juncus militaris Bigelow — Bayonet-rush [S5] [N]; Juncaceae -- 32 published photos
Juncus pelocarpus E. Meyer — Pondshore-rush [S5] [N]; Juncaceae -- 24 published photos
Juncus pylaei Laharpe — Soft Rush [S5] [N]; Juncaceae
Juncus secundus Beauv. ex Poiret — Secund Rush [S4] [N]; Juncaceae -- 5 published photos
Juncus tenuis Willd. — Path-rush, Yard-rush [S5] [N]; Juncaceae -- 6 published photos
Juniperus communis L. var. depressa Pursh — Common Juniper [S5] [N]; Cupressaceae as Juniperus communis var. depressa -- 28 published photos
Juniperus virginiana L. var. virginiana — Eastern Red Cedar [S5] [N]; Cupressaceae -- 55 published photos
Kalmia angustifolia L. var. angustifolia — Sheep-laurel [S5] [N]; Ericaceae -- 25 published photos
Kalmia latifolia L. — Mountain-laurel [S5] [N]; Ericaceae -- 28 published photos
Knautia arvensis (L.) Coulter — Blue Buttons [SNA] [I]; Caprifoliaceae
Kochia scoparia (L.) Schrader — Summer-cypress [SNA] [I]; Amaranthaceae in Chenopodiaceae -- 11 published photos
Krigia virginica (L.) Willd. — Dwarf Dandelion [S5] [N]; Asteraceae -- 25 published photos
Lachnanthes caroliana (Lam.) Dandy [SC] [S3] [N]; Haemodoraceae as Lachnanthes caroliniana -- 17 published photos
Lactuca biennis (Moench) Fern. — Blue Wild Lettuce [S5] [N]; Asteraceae -- 10 published photos
Lactuca canadensis L. — Yellow Wild Lettuce [S5] [N]; Asteraceae -- 16 published photos
Lactuca serriola L. — Prickly Lettuce [SNA] [I]; Asteraceae -- 21 published photos
Lactuca ×morssii B.L. Robinson — Morss's Wild Lettuce [SNR] [N]; Asteraceae
Lamium amplexicaule L. var. ampliexicaule Henbit [SNA] [I]; Lamiaceae -- 5 published photos
Lamium maculatum L. — Spotted Dead Nettle [SNA] [I]; Lamiaceae
Lamium purpureum L. var. incisum (Willd.) Pers. — Intermediate Henbit [SNA] [I]; Lamiaceae -- 9 published photos
Lamium purpureum L. var. purpureum — Purple Dead Nettle, Red Dead Nettle [SNA] [I]; Lamiaceae -- 9 published photos
Larix decidua P. Miller — European Larch [SNR] [I]; Pinaceae -- 16 published photos
Larix laricina (DuRoi) Koch — Tamarack [S5] [N]; Pinaceae -- 13 published photos
Lathyrus japonicus Willd. var. maritimus (L.) Kartesz & Gandhi — Beach-pea [S4S5] [N]; Fabaceae as Lathyrus japonicus var. maritimus -- 10 published photos
Lathyrus palustris L. — Vetchling, Marsh-pea [WL] [SNR] [N]; Fabaceae
Lathyrus sylvestris L. — Flat Pea [SNA] [I]; Fabaceae -- 5 published photos
Lechea intermedia Leggett ex Britton var. intermedia — Large-podded Pinweed [S4] [N]; Cistaceae -- 21 published photos
Lechea maritima Leggett ex B.S.P. var. maritima — Beach-pinweed [S5] [N]; Cistaceae -- 60 published photos
Lechea minor L. — Thyme-leaf Pinweed [WL] [S2S3] [N]; Cistaceae -- 18 published photos
Lechea mucronata Raf. — Hairy Pinweed [S5] [N]; Cistaceae -- 43 published photos
Lechea pulchella Raf. var. pulchella — Leggett's Pinweed [S3S4] [N]; Cistaceae as Lechea pulchella var. pulchella -- 4 published photos
Lechea tenuifolia Michaux — Slender Pinweed [S4?] [N]; Cistaceae -- 17 published photos
Leersia oryzoides (L.) Sw. — Rice Cut-grass [S5] [N]; Poaceae -- 30 published photos
Leersia virginica Willd. — White Cut-grass [S4S5] [N]; Poaceae -- 3 published photos
Lemna minor L. — Duckweed [S5] [N]; Araceae in Lemnaceae -- 4 published photos
Lemna perpusilla Torrey — Tiny Duckweed [H] [SH] [N]; Araceae
Lemna valdiviana Phil. — Valdivia Duckweed [H] [SH] [N]; Araceae in Lemnaceae -- 2 published photos
Leontodon saxatilis Lam. ssp. saxatilis — Little Fall-dandelion [SNA] [I]; Asteraceae
Leonurus cardiaca L. — Motherwort [SNA] [I]; Lamiaceae -- 4 published photos
Lepidium campestre (L.) Aiton f. — Cow-cress [SNA] [I]; Brassicaceae -- 7 published photos
Lepidium densiflorum Schrader var. densiflorum — Prairie-peppergrass [SNA] [I]; Brassicaceae -- 1 published photos
Lepidium latifolium L. — Broad-leaved Pepperweed, Tall Pepperweed [invasive] [SNA] [I]; Brassicaceae -- 8 published photos
Lepidium ruderale L. — Stinking Peppergrass [SNA] [I]; Brassicaceae
Lepidium virginicum L. var. virginicum — Poor-man's Pepper [S5] [N]; Brassicaceae -- 21 published photos
Lespedeza angustifolia (Pursh) Ell. — Narrow-leaved Bush-clover [WL] [S3?] [N]; Fabaceae -- 13 published photos
Lespedeza capitata Michaux — Round-headed Bush-clover [S5] [N]; Fabaceae -- 11 published photos
Lespedeza cuneata (Dum.-Cours.) G. Don — Sericea Lespedeza [SNA] [I]; Fabaceae -- 15 published photos
Lespedeza hirta (L.) Hornem. ssp. hirta — Hairy Bush-clover [S5] [N]; Fabaceae -- 7 published photos
Lespedeza stuevei Nutt. — Stueve's Bush-clover [H] [SH] [N]; Fabaceae -- 4 published photos
Lespedeza thunbergii (DC.) Nakai — Tall Bush-clover [SNA] [W]; Fabaceae as Lespedeza thunbergii ssp. formosa -- 25 published photos
Lespedeza violacea (L.) Pers. — Wand Bush-clover [S5] [N]; Fabaceae -- 16 published photos
Lespedeza virginica (L.) Britton — Virginia Bush-clover [S4] [N]; Fabaceae -- 8 published photos
Lespedeza ×brittonii Bicknell [SNR] [N]; Fabaceae
Lespedeza ×nuttallii Darl. [SNR] [N]; Fabaceae as Lespedeza x nuttallii
Leucanthemum vulgare Lam. — Oxeye-daisy [SNA] [I]; Asteraceae -- 7 published photos
Liatris scariosa (L.) Willd. var. novae-angliae — New England Blazing-star [SC] [S3] [N]; Asteraceae as Liatris novae-angliae -- 21 published photos
Liatris spicata (L.) Willd. var. spicata — Spiked Blazing-star [SNA] [W]; Asteraceae
Ligusticum scothicum L. — Scotch Lovage [S4] [N]; Apiaceae -- 4 published photos
Ligustrum obtusifolium Sieb. & Zucc. var. obtusifolium — Japanese Privet [likely invasive] [SNA] [I]; Oleaceae -- 16 published photos
Ligustrum sinense Lour. — Chinese Privet [SNA] [W]; Oleaceae
Ligustrum vulgare L. — Common Privet [SNA] [I]; Oleaceae
Lilaeopsis chinensis (L.) Kuntze — lilaeopsis [WL] [S2?] [N]; Apiaceae
Lilium canadense L. — Canada Lily [S4] [N]; Liliaceae -- 17 published photos
Lilium philadelphicum L. — Wood-lily [S4] [N]; Liliaceae -- 26 published photos
Lilium superbum L. — Turk's Cap Lily [S3S4] [N]; Liliaceae -- 3 published photos
Limonium carolinianum (Walter) Britton — Sea-lavender [S4] [N]; Plumbaginaceae -- 21 published photos
Limosella australis R. Br. — Atlantic Mudwort [S4] [N]; Scrophulariaceae
Linaria vulgaris P. Miller — Butter-and-eggs [SNA] [I]; Plantaginaceae in Scrophulariaceae -- 7 published photos
Lindera benzoin (L.) Blume — Spicebush [S5] [N]; Lauraceae -- 33 published photos
Lindernia dubia (L.) Pennell var. anagallidea — False Pimpernel [S5] [N]; Linderniaceae in Scrophulariaceae -- 11 published photos
Lindernia dubia (L.) Pennell var. dubia — False Pimpernel [S5] [N]; Linderniaceae in Scrophulariaceae -- 11 published photos
Linnaea borealis L. ssp. americana (Forbes) Hultén ex Clausen — Twinflower [WL] [S3] [N]; Caprifoliaceae -- 8 published photos
Linum intercursum Bicknell — Sandplain Flax [SC] [S3] [N]; Linaceae -- 11 published photos
Linum medium (Planchon) Britton var. texanum — Texan Flax [T] [S2] [N]; Linaceae
Linum usitatissimum L. — Common Flax [SNA] [I]; Linaceae -- 8 published photos
Linum virginianum L. — Woodland Yellow Flax [S5] [N]; Linaceae -- 14 published photos
Liparis loeselii (L.) L. C. Rich. — Green Twayblade [S4] [N]; Orchidaceae
Lipocarpha micrantha (Vahl) G. Tucker — Dwarf Bulrush [T] [S2] [N]; Cyperaceae
Liriodendron tulipifera L. — Tulip-tree [S4] [I]; Magnoliaceae -- 13 published photos
Lobelia cardinalis L. — Cardinal-flower [S4] [N]; Campanulaceae -- 19 published photos
Lobelia dortmanna L. — Water-lobelia [S4] [N]; Campanulaceae -- 12 published photos
Lobelia inflata L. — Indian Tobacco [S5] [N]; Campanulaceae -- 18 published photos
Lobelia siphilitica L. var. siphilitica — Great Blue Lobelia [E] [S1] [I]; Campanulaceae -- 2 published photos
Lobelia spicata Lam. var. spicata — Spiked Lobelia, Pale-spike Lobelia [S4] [N]; Campanulaceae
Lobularia maritima (L.) Desv. — Sweet Alyssum [SNA] [I]; Brassicaceae -- 1 published photos
Lolium multiflorum Lam. — Italian Rye-grass [SNA] [I]; Poaceae -- 2 published photos
Lolium perenne L. — Perennial Rye-grass [SNA] [I]; Poaceae -- 9 published photos
Lonicera dioica L. — Wild Honeysuckle [S4] [I]; Caprifoliaceae
Lonicera japonica Thunb. — Japanese Honeysuckle [invasive] [SNA] [I]; Caprifoliaceae -- 18 published photos
Lonicera morrowii A. Gray — Morrow Honeysuckle [invasive] [SNA] [I]; Caprifoliaceae -- 30 published photos
Lonicera sempervirens L. var. sempervirens — Trumpet-honeysuckle [WL] [SNR] [I?]; Caprifoliaceae -- 8 published photos
Lonicera ×bella Zabel — Hybrid Honeysuckle [invasive] [SNA] [I]; Caprifoliaceae as Lonicera x bella -- 13 published photos
Lotus corniculatus L. — Birdsfoot-trefoil [SNA] [I]; Fabaceae -- 8 published photos
Ludwigia palustris (L.) Ell. — Water Purslane [S5] [N]; Onagraceae -- 18 published photos
Ludwigia sphaerocarpa Elliott — Round-fruited Seedbox [E] [S1] [N]; Onagraceae -- 6 published photos
Lupinus perennis L. ssp. perennis — Wild Lupine [WL] [S3S4] [N]; Fabaceae -- 11 published photos
Luzula campestris (L.) DC. — Field Wood-rush [SNA] [I]; Juncaceae
Luzula luzuloides (Lam.) Dandy & Wilm. Krecz. — White-flowered Wood-rush [SNA] [W]; Juncaceae
Luzula multiflora (Ehrh.) Lej. ssp. multiflora — Common Wood-rush [S5] [N]; Juncaceae -- 17 published photos
Lychnis chalcedonica L. — Scarlet Lychnis [SNA] [I]; Caryophyllaceae
Lychnis coronaria (L.) Murray — Mullein-pink [SNA] [I]; Caryophyllaceae
Lychnis flos-cuculi L. ssp. flos-cuculi — Ragged Robin [SNA] [I]; Caryophyllaceae -- 6 published photos
Lycium barbarum L. — Matrimony-vine [SNA] [I]; Solanaceae
Lycopodiella appressa (Chapman) Cranfill — Southern Bog-clubmoss [S4] [N]; Lycopodiaceae
Lycopodiella inundata (L.) Holub — Northern Bog-clubmoss [S5] [N]; Lycopodiaceae -- 12 published photos
Lycopodiella ×copelandii (Eiger) Cranfill — Copeland's Clubmoss [S?] [N]; Lycopodiaceae
Lycopodium clavatum L. — Staghorn Clubmoss [S5] [N]; Lycopodiaceae -- 8 published photos
Lycopus americanus Muhl. ex W. Barton — American Water-horehound [S5] [N]; Lamiaceae -- 9 published photos
Lycopus amplectens Raf. — Sessile Water-horehound [WL] [S2S3] [N]; Lamiaceae -- 12 published photos
Lycopus europaeus L. — European Water-horehound [SNA] [I]; Lamiaceae -- 1 published photos
Lycopus rubellus Moench — Gypsywort Water-horehound [E] [S1S2] [N]; Lamiaceae
Lycopus uniflorus Michaux — Northern Water-horehound [S5] [N]; Lamiaceae -- 38 published photos
Lycopus virginicus L. — Virginia Water-horehound [S5] [N]; Lamiaceae -- 15 published photos
Lygodium palmatum (Bernh. ex Schrader) Sw. — Climbing Fern [SC] [S3] [N]; Schizaeaceae in -- 13 published photos
Lyonia ligustrina (L.) DC. var. ligustrina — Maleberry [S5] [N]; Ericaceae -- 39 published photos
Lysimachia borealis (Raf.) U Manns & A. Anderb. — Starflower [S5] [N]; Myrsinaceae as Trientalis borealis in Primulaceae -- 10 published photos
Lysimachia ciliata L. — Fringed Loosestrife [S4] [N]; Myrsinaceae in Primulaceae -- 3 published photos
Lysimachia hybrida Michaux — Narrow-leaved Loosestrife [S4] [N]; Myrsinaceae in Primulaceae -- 11 published photos
Lysimachia maritima (L.) Galasso, Banfi, & Soldano — Sea-milkwort [S4] [N]; Myrsinaceae as Glaux maritima in Primulaceae -- 5 published photos
Lysimachia nummularia L. — Moneywort [invasive] [SNA] [I]; Myrsinaceae in Primulaceae -- 4 published photos
Lysimachia punctata L. — Spotted Loosestrife [SNA] [I]; Myrsinaceae
Lysimachia quadrifolia L. — Whorled Loosestrife [S5] [N]; Myrsinaceae in Primulaceae -- 11 published photos
Lysimachia terrestris (L.) B.S.P. — Swamp-candles [S5] [N]; Myrsinaceae in Primulaceae -- 12 published photos
Lysimachia thyrsiflora L. — Tufted Loosestrife [S4] [N]; Myrsinaceae in Primulaceae -- 9 published photos
Lysimachia vulgaris L. — Garden-loosestrife [SNA] [I]; Myrsinaceae
Lysimachia ×producta (A. Gray) Fern. [SNR] [N]; Myrsinaceae
Lythrum hyssopifolia L. — Annual Loosestrife [SNA] [I]; Lythraceae
Lythrum salicaria L. — Purple Loosestrife [invasive] [SNA] [I]; Lythraceae -- 16 published photos
Madia sativa Molina — Large-headed Coast-madia [SNA] [W]; Asteraceae
Magnolia acuminata L. — Cucumber-magnolia [SNA] [I]; Magnoliaceae
Magnolia tripetala (L.) L. — Umbrella-magnolia [SNA] [I]; Magnoliaceae
Maianthemum canadense Desf. — Canada Mayflower [S5] [N]; Ruscaceae in Liliaceae -- 9 published photos
Maianthemum racemosum (L.) Link ssp. racemosum — False Solomon's Seal [S5] [N]; Ruscaceae as Smilacina racemosa in Liliaceae -- 10 published photos
Maianthemum stellatum (L.) Link — Starry Solomon's Seal [S4] [N]; Ruscaceae as Smilacina stellata in Liliaceae -- 7 published photos
Maianthemum trifolium (L.) Sloboda — Three-leaved Solomon's Seal [WL] [S3?] [N]; Ruscaceae
Malus baccata (L.) Borkh. — Siberian Crabapple [SNA] [I]; Rosaceae -- 7 published photos
Malus pumila P. Miller — Apple [SNA] [I]; Rosaceae -- 1 published photos
Malus sieboldii (Regel) Rehder — Toringo Crabapple [SNA] [I]; Rosaceae -- 8 published photos
Malva moschata L. — Musk-mallow [SNA] [I]; Malvaceae -- 4 published photos
Malva neglecta Wallr. — Cheeses, Common Mallow [SNA] [I]; Malvaceae -- 5 published photos
Malva sylvestris L. — High Mallow [SNA] [I]; Malvaceae
Malva verticillata L. — Crisped Mallow, Whorled Mallow [SNA] [I]; Malvaceae
Marrubium vulgare L. — Horehound [SNA] [I]; Lamiaceae
Matricaria discoidea DC. — Pineapple-weed [SNA] [I]; Asteraceae -- 3 published photos
Medeola virginiana L. — Indian Cucumber-root [S5] [N]; Liliaceae -- 22 published photos
Medicago lupulina L. — Black Medick [SNA] [I]; Fabaceae -- 3 published photos
Medicago sativa L. — Blue Alfalfa, Lucerne [SNA] [I]; Fabaceae -- 3 published photos
Melampyrum lineare Desr. — Cow-wheat [S5] [N]; Orobanchaceae in Scrophulariaceae -- 9 published photos
Melilotus albus Medicus — White Sweet-clover [SNA] [I]; Fabaceae -- 5 published photos
Melilotus officinalis (L.) Lam. — Yellow Sweet-clover [SNA] [I]; Fabaceae -- 4 published photos
Menispermum canadense L. — Moonseed [WL] [S3] [I]; Menispermaceae
Mentha arvensis L. ssp. parietariaefolia (Becker) Briq. — Field-mint [SNA] [I]; Lamiaceae
Mentha canadensis L. — American Field-mint [S4S5] [N]; Lamiaceae -- 5 published photos
Mentha spicata L. ssp. spicata — Spearmint [SNA] [I]; Lamiaceae
Mentha ×gracilis Sole — Spotted Whorled Mint [SNA] [I]; Lamiaceae as Mentha x gracilis
Mentha ×piperita L. — Peppermint [SNA] [I]; Lamiaceae as Mentha x piperita -- 4 published photos
Mentha ×rotundifolia (L.) Hudson — Round-leaved Mint [SNA] [I]; Lamiaceae
Menyanthes trifoliata L. — Buckbean [S4] [N]; Menyanthaceae -- 7 published photos
Mertensia maritima (L.) S.F. Gray var. maritima — Oysterleaf [E] [S1] [N]; Boraginaceae
Mibora minima (L.) Desv. [SNA] [W]; Poaceae
Micranthes pensylvanica (L.) Haw. — Swamp-saxifrage [S4] [N]; Saxifragaceae as Saxifraga pensylvanica -- 11 published photos
Micranthes virginiensis (Michaux) Small — Early Saxifrage [S4] [N]; Saxifragaceae as Saxifraga virginiensis
Mikania scandens (L.) Willd. — Climbing Hempweed [S4] [N]; Asteraceae -- 16 published photos
Mimulus ringens L. — Blue Monkey-flower [S5] [N]; Phrymaceae in Scrophulariaceae -- 10 published photos
Mirabilis nyctaginea (Michaux) MacMillan — Heart-leaved Umbrella-wort [SNA] [I]; Nyctaginaceae -- 7 published photos
Mitchella repens L. — Partridge-berry [S5] [N]; Rubiaceae -- 14 published photos
Moehringia lateriflora (L.) Fenzl — Grove-sandwort [S5] [N]; Caryophyllaceae -- 6 published photos
Mollugo verticillata L. — Carpetweed [SNA] [I]; Molluginaceae -- 13 published photos
Monarda didyma L. — Bee-balm [SNA] [I]; Lamiaceae
Monarda fistulosa L. ssp. fistulosa — Wild Bergamot [S4?] [I]; Lamiaceae
Monarda media Willd. — Purple Bergamot [SNA] [I]; Lamiaceae
Monarda punctata ssp. punctata L. var. villicaulis — Dotted Horse-mint [SNA] [W]; Lamiaceae
Moneses uniflora (L.) A. Gray — One-flowered Pyrola [WL] [S2S3] [N]; Ericaceae in Pyrolaceae
Monotropa uniflora L. — Indian Pipe [S5] [N]; Ericaceae in Monotropaceae -- 15 published photos
Montia linearis (Douglas ex Hooker) Greene — Linear Montia [SNA] [W]; Portulacaceae
Morella pensylvancia (Mirbel) Kartesz — Bayberry [S5] [N]; Myricaceae as Myrica pensylvanica -- 28 published photos
Morus alba L. — White Mulberry [SNA] [I]; Moraceae -- 8 published photos
Muhlenbergia capillaris (Lam.) Trin. — Hairgrass [H] [SH] [N]; Poaceae
Muhlenbergia frondosa (Poiret) Fern. — Wirestem Muhly [S5] [N]; Poaceae
Muhlenbergia glomerata (Willd.) Trin. — Marsh Muhly [S5] [N]; Poaceae
Muhlenbergia mexicana (L.) Trin. — Satingrass [S5] [N]; Poaceae
Muhlenbergia schreberi J.F. Gmelin — Nimblewill [S5] [N]; Poaceae -- 2 published photos
Muhlenbergia uniflora (Muhl.) Fern. — Northern Muhly [S5] [N]; Poaceae -- 18 published photos
Muscari botryoides (L.) P. Miller — Grape-hyacinth [SNA] [I]; Hyacinthaceae
Myosotis laxa Lehm. — Smaller Forget-me-not [S4] [N]; Boraginaceae -- 5 published photos
Myosotis scorpioides L. — True Forget-me-not [likely invasive] [SNA] [I]; Boraginaceae
Myosotis stricta Link ex Roemer & J.A. Schultes — Blue Scorpion-grass [SNA] [I]; Boraginaceae -- 4 published photos
Myosotis sylvatica Ehrh. ex Hoffm. — Garden Forget-me-not [SNA] [I]; Boraginaceae
Myosotis verna Nutt. — Spring Scorpion-grass [S4] [N]; Boraginaceae
Myrica gale L. — Sweet Gale [S5] [N]; Myricaceae -- 20 published photos
Myriophyllum heterophyllum Michaux — Variable Water-milfoil [invasive] [SNA] [I]; Haloragaceae -- 10 published photos
Myriophyllum humile (Raf.) Morong — Lowly Water-milfoil [S5] [N]; Haloragaceae -- 24 published photos
Myriophyllum pinnatum (Walter) B.S.P. — Pinnate Water-milfoil [SC] [S3] [N]; Haloragaceae
Myriophyllum tenellum Bigelow — Leafless Water-milfoil [S4] [N]; Haloragaceae
Nabalus serpentarius (Pursh) Hooker — Lion's Foot [E] [S1] [N]; Asteraceae
Nabalus trifoliolatus Cass. — Gall-of-the-earth [S5] [N]; Asteraceae as Prenanthes trifoliolata -- 16 published photos
Najas flexilis (Willd.) Rostk. & Schmidt — Common Naiad [S5] [N]; Hydrocharitaceae
Najas gracillima (A. Braun) Magnus — Slender Naiad [S5] [N]; Hydrocharitaceae in Najadaceae -- 2 published photos
Narcissus poeticus L. — Poet's Narcissus [SNA] [I]; Amaryllidaceae
Nasturtium microphyllum Boenn. ex Reichenb. — Watercress [SNA] [I]; Brassicaceae
Nelumbo lutea Willd. — American Lotus [SNA] [I]; Nelumbonaceae
Nepeta cataria L. — Catnip [SNA] [I]; Lamiaceae -- 1 published photos
Nicandra physalodes (L.) Gaertner — Apple-of-Peru [SNA] [I]; Solanaceae
Nuphar variegata Durand ex Clinton — Yellow Water-lily, Cow-lily [S5] [N]; Nymphaeaceae -- 17 published photos
Nuttallanthus canadensis (L.) D.A. Sutton — Blue Toadflax [S5] [N]; Plantaginaceae in Scrophulariaceae -- 28 published photos
Nymphaea odorata Aiton — White Water-lily, Fragrant Water-lily [S5] [N]; Nymphaeaceae -- 19 published photos
Nymphoides cordata (Ell.) Fern. — Floating Heart [S5] [N]; Menyanthaceae -- 14 published photos
Nyssa sylvatica Marshall — Black Gum [S5] [N]; Cornaceae in Nyssaceae -- 75 published photos
Oclemena acuminata (Michaux) Nesom — Whorled Wood-aster [S5] [N]; Asteraceae as Aster acuminatus -- 14 published photos
Oclemena ×blakei (Porter) Nesom — Blake's Aster [SNR] [N]; Asteraceae as Aster x blakei -- 4 published photos
Oenothera biennis L. — Common Evening-primrose [S5] [N]; Onagraceae -- 27 published photos
Oenothera fruticosa L. ssp. glauca (Michaux) Straley — Sundrops [N?]; Onagraceae
Oenothera gaura W.L. Wagner & Hoch — Biennial Gaura [SNA] [I]; Onagraceae
Oenothera oakesiana (A. Gray) Robbins ex S. Watson & Coulter — Cross-shaped Evening-primrose [S4] [N]; Onagraceae
Oenothera parviflora L. — Small-flowered Evening-primrose [S4] [N]; Onagraceae
Oenothera perennis L. — Little Sundrops [S5] [N]; Onagraceae
Onoclea sensibilis L. — Sensitive Fern [S5] [N]; Onocleaceae in Dryopteridaceae -- 23 published photos
Onopordum acanthium L. ssp. acanthium — Scotch Thistle [SNA] [I]; Asteraceae
Ophioglossum pusillum Raf. — Adder's Tongue Fern [T] [S2] [N]; Ophioglossaceae
Opuntia humifusa (Raf.) Raf. — Eastern Prickly Pear [E] [S1] [I]; Cactaceae in
Origanum vulgare L. — Marjoram [SNA] [I]; Lamiaceae
Ornithogalum umbellatum L. — Star-of-Bethlehem [SNA] [I]; Hyacinthaceae in Liliaceae -- 4 published photos
Orobanche uniflora L. — One-flowered Cancer-root [S5] [N]; Orobanchaceae -- 4 published photos
Orontium aquaticum L. — Golden Club [E] [S1] [N]; Araceae
Oryzopsis asperifolia Michaux — Spreading Ricegrass [S5] [N]; Poaceae, Oryzopsis asperifolia
Osmorhiza longistylis (Torrey) DC. — Aniseroot [S4] [N]; Apiaceae
Osmunda claytoniana L. — Interrupted Fern [S5] [N]; Osmundaceae -- 17 published photos
Osmunda regalis L. var. spectabilis (Willd.) A. Gray — Royal Fern [S5] [N]; Osmundaceae -- 21 published photos
Osmundastrum cinnamomeum (L.) C. Presl — Cinnamon Fern [S5] [N]; Osmundaceae as Osmunda cinnamomea -- 22 published photos
Ostrya virginiana (P. Miller) K. Koch — Hop-hornbeam [S5] [N]; Betulaceae -- 21 published photos
Othocallis siberica (Haw. ex Andr.) Speta — Siberian Squill [SNA] [I]; Hyacinthaceae as Scilla sibirica in Liliaceae -- 6 published photos
Oxalis dillenii Jacq. ssp. dillenii — Southern Yellow Wood-sorrel [S5] [N]; Oxalidaceae -- 9 published photos
Oxalis stricta L. — Common Yellow Wood-sorrel [S5] [N]; Oxalidaceae -- 15 published photos
Packera aurea (L.) A. & D. Löve — Golden Ragwort [S5] [N]; Asteraceae as Senecio aureus -- 12 published photos
Packera paupercula (Michaux) W.A. Weber & A. Löve — Balsam-ragwort [S4] [N]; Asteraceae
Panax trifolius L. — Dwarf Ginseng [S4] [N]; Apiaceae in Araliaceae -- 18 published photos
Panicum capillare L. ssp. capillare — Witch-grass [S5] [N]; Poaceae -- 6 published photos
Panicum dichotomiflorum Michaux var. dichotomiflorum — Fall Panic-grass [S5] [N]; Poaceae -- 22 published photos
Panicum dichotomiflorum Michaux var. puritanorum Svenson — Svenson's Panic-grass [S4] [N]; Poaceae -- 22 published photos
Panicum miliaceum L. ssp. milliaceum — Broom-corn Millet [SNA] [I]; Poaceae
Panicum philadelphicum Bernh. ex Trin. ssp. philadelphicum — Philadelphia Panic-grass [SC] [S3] [N]; Poaceae
Panicum rigidulum Bosc ex Nees subsp. pubescens — Long-leaved Panic-grass [T] [S2] [N]; Poaceae
Panicum rigidulum Bosc ex Nees ssp. rigidulum — Flat-stemmed Panic-grass [S5] [N]; Poaceae -- 12 published photos
Panicum verrucosum Muhl. — Warty Panic-grass [S4] [N]; Poaceae -- 21 published photos
Panicum virgatum L. — Switchgrass [S5] [N]; Poaceae -- 28 published photos
Papaver rhoeas L. — Corn-poppy [SNA] [I]; Papaveraceae
Papaver somniferum L. — Opium-poppy [SNA] [I]; Papaveraceae
Parathelypteris noveboracensis (L.) Ching — New York Fern [S5] [N]; Thelypteridaceae as Thelypteris noveboracensis -- 9 published photos
Parathelypteris simulata (Davenport) Holttum — Massachusetts Fern [S5] [N]; Thelypteridaceae as Thelypteris simulata -- 17 published photos
Parthenocissus quinquefolia (L.) Planchon — Virginia Creeper [S5] [N]; Vitaceae -- 26 published photos
Parthenocissus vitacea (Knerr) A.S. Hitchc. — Grape-woodbine [S5] [N]; Vitaceae
Paspalum setaceum Michaux var. muhlenbergii (Nash) D. Banks — Muhlenberg's Bead-grass [S5] [N]; Poaceae as Paspalum setaceum var. muhlenbergii -- 11 published photos
Paspalum setaceum Michaux var. psammophilum (Nash) D. Banks — Sand Bead-grass [WL] [S2S3] [N]; Poaceae
Paspalum setaceum var. setaceum Michaux — Small-fruited or Slender Bead-grass [WL] [S3?] [N]; Poaceae
Pastinaca sativa L. — Field-parsnip [SNA] [I]; Apiaceae -- 8 published photos
Pedicularis canadensis L. ssp. canadensis — Wood-betony [S5] [N]; Orobanchaceae in Scrophulariaceae -- 8 published photos
Peltandra virginica (L.) Schott ex Schott & Endl. — Arrow-arum [S5] [N]; Araceae -- 12 published photos
Penstemon digitalis Nutt. ex Sims — Tall White Beard-tongue [S4] [N?]; Plantaginaceae in Scrophulariaceae
Penstemon hirsutus (L.) Willd. — Hairy Beard-tongue [E] [S1] [I]; Plantaginaceae
Penstemon pallidus Small — Pale Beard-tongue [SNA] [I?]; Plantaginaceae
Penthorum sedoides L. — Ditch-stonecrop [S4] [N]; Penthoraceae in Crassulaceae -- 7 published photos
Persicaria amphibia (L.) S.F. Gray — Water Smartweed [S5] [N]; Polygonaceae as Polygonum amphibium var. emersum -- 15 published photos
Persicaria arifolia (L.) Haroldson — Halberd-leaf Tearthumb [S5] [N]; Polygonaceae as Polygonum arifolium -- 11 published photos
Persicaria careyi (Olney) Greene — Carey's Smartweed [S?] [N]; Polygonaceae as Polygonum careyi -- 21 published photos
Persicaria hydropiper (L.) Opiz — Water-pepper [S5] [I]; Polygonaceae as Polygonum hydropiper
Persicaria hydropiperoides (Michaux) Small — False Water-pepper, Mild Water-pepper [S5] [N]; Polygonaceae as Polygonum hydropiperoides -- 11 published photos
Persicaria lapathifolia (L.) S.F. Gray — Willow-weed Smartweed, Nodding Smartweed, Dock-lea [S5] [N]; Polygonaceae as Polygonum lapathifolium -- 2 published photos
Persicaria longiseta (Bruijn) Kitagawa — Chinese Smartweed [SNA] [I]; Polygonaceae as Polygonum cespitosum var. longisetum -- 18 published photos
Persicaria maculosa S.F. Gray — Lady's Thumb [SNA] [I]; Polygonaceae as Polygonum persicaria -- 21 published photos
Persicaria orientalis (L.) Spach — Prince's Feather [SNA] [I]; Polygonaceae
Persicaria pensylvanica (L.) G. Maza — Pinkweed, Smartweed, Pennsylvania Smartweed [S5] [N]; Polygonaceae as Polygonum pensylvanicum -- 21 published photos
Persicaria punctata (Ell.) Small — Perennial Water-smartweed, Dotted Smartweed [S5] [N]; Polygonaceae as Polygonum punctatum -- 18 published photos
Persicaria puritanorum (Fern.) Soják — Pondshore Smartweed [SC] [S3] [N]; Polygonaceae as Polygonum puritanorum -- 5 published photos
Persicaria robustior (Small) Bicknell — Big Water-smartweed [S4] [N]; Polygonaceae as Polygonum robustius -- 6 published photos
Persicaria sagittata (L.) H. Gross — Arrow-leaf Tearthumb [S5] [N]; Polygonaceae as Polygonum sagittatum -- 12 published photos
Persicaria setacea (Baldw.) Small — Swamp Smartweed [T] [S2] [N]; Polygonaceae
Peucedanum palustre (L.) Moench — Milk-parsley [SNA] [I]; Apiaceae
Phalaris arundinacea L. — Reed Canary-grass [invasive] [S5] [I?]; Poaceae -- 21 published photos
Phegopteris connectilis (Michaux) Watt — Northern Beech-fern [S5] [N]; Thelypteridaceae -- 9 published photos
Phegopteris hexagonoptera (Michaux) Fée — Southern Beech-fern [S4] [N]; Thelypteridaceae -- 5 published photos
Phleum pratense L. — Timothy [SNA] [I]; Poaceae -- 14 published photos
Phlox subulata L. ssp. subulata — Moss-phlox [SNA] [I]; Polemoniaceae
Phragmites australis (Cav.) Trin. ex Steudel — Phragmites, Common Reed [invasive] [SNA] [I]; Poaceae -- 34 published photos
Physalis grisea (Waterfall) M. Martinez — Strawberry-tomato [N]; Solanaceae
Physalis heterophylla Nees var. heterophylla — Clammy Ground-cherry [S4] [N]; Solanaceae
Physocarpus opulifolius (L.) Maxim. — Ninebark [SNA] [I]; Rosaceae
Physostegia virginiana (L.) Bentham ssp. virginiana — False Dragonhead [SNA] [I]; Lamiaceae
Phytolacca americana L. var. americana — Pokeweed [S5] [N]; Phytolaccaceae -- 15 published photos
Picea glauca (Moench) Voss — White Spruce [SNR] [I]; Pinaceae -- 25 published photos
Picea mariana (P. Miller) B.S.P. — Black Spruce [S5] [N]; Pinaceae -- 31 published photos
Picris hieracioides L. — Hawkweed Oxtongue [SNA] [I]; Asteraceae
Pilea pumila (L.) A. Gray — Clearweed [S5] [N]; Urticaceae -- 11 published photos
Pinus banksiana Lamb. — Jack Pine [SNR] [I]; Pinaceae -- 9 published photos
Pinus rigida Miller — Pitch-pine [S5] [N]; Pinaceae -- 89 published photos
Pinus strobus L. — White Pine [S5] [N]; Pinaceae -- 57 published photos
Piptatherum pungens (Torr ex Spreng.) Dorn — Little Ricegrass [S5] [N]; Poaceae as Oryzopsis pungens -- 3 published photos
Piptochaetium avenaceum (L.) Parodi — Black Oatgrass [WL] [SNR] [N]; Poaceae -- 18 published photos
Pityopsis falcata (Pursh) Nutt. — Sickle-leaved Golden-aster [S4] [N]; Asteraceae -- 25 published photos
Plantago arenaria Waldst. & Kit. — Sand-plantain [SNA] [I]; Plantaginaceae
Plantago aristata Michaux — Bracted Plantain [SNA] [I]; Plantaginaceae -- 13 published photos
Plantago intermedia DC. — Saltmarsh Plantain [S4] [N]; Plantaginaceae
Plantago lanceolata L. — Ribgrass Plantain [SNA] [I]; Plantaginaceae -- 7 published photos
Plantago major L. — Common Plantain, White Man's Foot [SNA] [I]; Plantaginaceae -- 8 published photos
Plantago maritima L. var. juncoides (Lam.) A. Gray — Seaside Plantain [S4S5] [N]; Plantaginaceae as Plantago maritima var. juncoides -- 12 published photos
Plantago pusilla Nutt. — Dwarf Plantain [WL] [S1?] [N]; Plantaginaceae
Plantago rugelii Dcne. — American Plantain [S5] [N]; Plantaginaceae
Platanthera blephariglottis (Willd.) Lindley var. blephariglottis — White-fringed Orchis [S4] [N]; Orchidaceae -- 12 published photos
Platanthera ciliaris (L.) Lindley — Yellow or Orange-fringed Orchis [H] [SH] [N]; Orchidaceae
Platanthera clavellata (Michaux) Luer — Club-spur Orchis [S4S5] [N]; Orchidaceae -- 11 published photos
Platanthera flava (L.) Lindley var. herbiola (R. Br.) Luer — Pale Green or Tubercled Orchis [T] [S2] [N]; Orchidaceae as Platanthera flava var. herbiola
Platanthera grandiflora (Bigelow) Lindley — Large Purple-fringed Orchis [S4] [N]; Orchidaceae -- 7 published photos
Platanthera lacera (Michaux) G. Don — Ragged-fringed Orchis [S4] [N]; Orchidaceae -- 7 published photos
Platanthera orbiculata (Pursh) Lindley — Round-leaved Orchis or Orchid [WL] [S1S2] [N]; Orchidaceae
Platanthera psycodes (L.) Lindl. — Small Purple-fringed Orchis [S4] [N]; Orchidaceae
Platanus occidentalis L. — Sycamore [S4] [N]; Platanaceae -- 26 published photos
Pluchea odorata (L.) Cass. var. succulenta (Fern.) Cronq. — Saltmarsh-fleabane [S4] [N]; Asteraceae as Pluchea odorata var. succulenta -- 8 published photos
Poa annua L. — Annual Bluegrass [SNA] [I]; Poaceae -- 16 published photos
Poa compressa L. — Canada Bluegrass [SNA] [I]; Poaceae -- 10 published photos
Poa palustris L. — Fowl-meadow Grass [S5] [N]; Poaceae -- 6 published photos
Poa pratensis L. ssp. pratensis — Kentucky Blue-grass, Junegrass [SNA] [I]; Poaceae -- 3 published photos
Poa pratensis L. ssp. angustifolia (L.) Arcang. — Narrow-leaved Kentucky Blue-grass [SNA] [I]; Poaceae -- 3 published photos
Podophyllum peltatum L. — May-apple [WL] [SNA] [I]; Berberidaceae
Pogonia ophioglossoides (L.) Ker-Gawler — Rose Pogonia [S5] [N]; Orchidaceae -- 9 published photos
Polygala cruciata L. var. aquilonia Fern. & Schub. — Cross-leaved Milkwort [S4] [N]; Polygalaceae -- 21 published photos
Polygala nuttallii Torrey & A. Gray — Nuttall's Milkwort [WL] [S3] [N]; Polygalaceae -- 13 published photos
Polygala polygama Walter — Racemed Milkwort [S4] [N]; Polygalaceae -- 18 published photos
Polygala sanguinea L. — Purple Milkwort [S4] [N]; Polygalaceae -- 7 published photos
Polygala verticillata L. — Whorled Milkwort [WL] [S2S3] [N]; Polygalaceae -- 9 published photos
Polygonatum biflorum (Walt.) Ell. — Giant Solomon's Seal [S4] [I]; Ruscaceae in Liliaceae -- 3 published photos
Polygonatum pubescens (Willd.) Pursh — Solomon's Seal [S5] [N]; Ruscaceae in Liliaceae -- 15 published photos
Polygonum articulatum L. — Jointweed [S4] [N]; Polygonaceae as Polygonella articulata -- 25 published photos
Polygonum aviculare L. — Knotweed, Doorweed [SNA] [I]; Polygonaceae -- 17 published photos
Polygonum buxiforme Small — Box-leaf Knotweed [S4] [N]; Polygonaceae
Polygonum erectum L. — Erect Knotweed [S3S4] [N]; Polygonaceae
Polygonum ramosissimum Michaux var. prolificum Small — Saltmarsh Knotweed [S4] [N]; Polygonaceae
Polygonum ramosissimum Michaux var. ramosissimum — Saltmarsh Knotweed, Bushy Knotweed [S4] [N]; Polygonaceae
Polygonum tenue Michaux — Rock Knotweed [WL] [S2S3] [N]; Polygonaceae -- 12 published photos
Polypodium virginianum L. — Rock Polypody [S5] [N]; Polypodiaceae -- 11 published photos
Polypodium ×incognitum Cusik [SNR] [N]; Polypodiaceae as Polypodium x incognitum
Polystichum acrostichoides (Michaux) Schott — Christmas-fern [S5] [N]; Dryopteridaceae -- 20 published photos
Pontederia cordata L. — Pickerel-weed [S5] [N]; Pontederiaceae -- 13 published photos
Populus alba L. — White Poplar [SNA] [I]; Salicaceae -- 7 published photos
Populus deltoides Bartram ex Marsh. — Cottonwood [S4] [I]; Salicaceae -- 14 published photos
Populus grandidentata Michaux — Big-toothed Aspen [S5] [N]; Salicaceae -- 28 published photos
Populus tremuloides Michaux — Trembling Aspen [SNA] [N]; Salicaceae -- 30 published photos
Populus ×jackii Sarg. — Balm-of-Gilead [SNA] [I]; Salicaceae as Populus x jackii -- 1 published photos
Portulaca grandiflora Hooker — Red Portulaca [SNA] [I]; Portulacaceae
Portulaca oleracea L. — Common Purslane [SNA] [I]; Portulacaceae -- 9 published photos
Potamogeton amplifolius Tuckerman — Big-leaved Pondweed [S5] [N]; Potamogetonaceae -- 3 published photos
Potamogeton berchtoldii Fieber — Slender Tiny Pondweed [S5] [N]; Potamogetonaceae
Potamogeton bicupulatus Fern. — Hairlike Pondweed [S5] [N]; Potamogetonaceae -- 1 published photos
Potamogeton confervoides Reichenb. — Alga-pondweed [T] [S2] [N]; Potamogetonaceae
Potamogeton epihydrus Raf. — Ribbon-leaf Pondweed [S5] [N]; Potamogetonaceae -- 15 published photos
Potamogeton foliosus Raf. ssp. foliosus — Leafy Pondweed [S4] [N]; Potamogetonaceae
Potamogeton gramineus L. — Grass-leaf Pondweed [S5] [N]; Potamogetonaceae -- 4 published photos
Potamogeton natans L. — Floating Pondweed [S5] [N]; Potamogetonaceae
Potamogeton oakesianus Robbins — Oakes' Pondweed [S5] [N]; Potamogetonaceae -- 12 published photos
Potamogeton perfoliatus L. — Perfoliate Pondweed [S5] [N]; Potamogetonaceae
Potamogeton pulcher Tuckerman — Spotted Pondweed [S4] [N]; Potamogetonaceae -- 1 published photos
Potamogeton robbinsii Oakes — Robbins Pondweed [S5] [N]; Potamogetonaceae
Potamogeton spirillus Tuckerman — Northern Snailseed-pondweed [S5] [N]; Potamogetonaceae
Potentilla argentea L. — Silvery Cinquefoil [SNA] [I]; Rosaceae -- 6 published photos
Potentilla canadensis L. — Dwarf Cinquefoil [S5] [N]; Rosaceae -- 13 published photos
Potentilla inclinata Vill. — Grayish Cinquefoil [SNA] [I]; Rosaceae
Potentilla norvegica L. — Three-finger [S5] [N]; Rosaceae -- 10 published photos
Potentilla recta L. — Rough-fruited Cinquefoil [SNA] [I]; Rosaceae -- 10 published photos
Potentilla simplex Michaux — Old Field Cinquefoil [S5] [N]; Rosaceae -- 5 published photos
Proserpinaca palustris L. — Mermaid-weed [S4] [N]; Haloragaceae -- 16 published photos
Proserpinaca pectinata Lam. — Cut-leaved Mermaid-weed [S4?] [N]; Haloragaceae -- 3 published photos
Prunella vulgaris L. ssp. lanceolata (W. Barton) Hultén — Wild Heal-all [S5] [N]; Lamiaceae as Prunella vulgaris ssp. lanceolata -- 2 published photos
Prunus alleghaniensis Porter — Allegheny Plum [SNA] [I]; Rosaceae
Prunus americana Marsh. — Wild Plum [S4?] [I]; Rosaceae
Prunus avium (L.) L. — Sweet Cherry [SNA] [I]; Rosaceae -- 7 published photos
Prunus cerasus L. — Sour Cherry [SNA] [I]; Rosaceae
Prunus hortulana Bailey — Wild Goose Plum [SNA] [W]; Rosaceae
Prunus maritima Marsh. var. maritima — Beach-plum [S4] [N]; Rosaceae -- 39 published photos
Prunus nigra Aiton — Canada Plum [S4?] [I]; Rosaceae
Prunus pensylvanica L. f. var. pensylvanica — Fire-cherry [S5] [N]; Rosaceae -- 28 published photos
Prunus serotina Ehrh. var. serotina — Black Cherry [S5] [N]; Rosaceae -- 52 published photos
Prunus susquehanae Willd. — Sand-cherry [S4?] [N]; Rosaceae -- 23 published photos
Prunus virginiana L. var. virginiana — Choke-cherry [S5] [N]; Rosaceae -- 23 published photos
Pseudognaphalium macounii (Greene) Kartesz — Clammy Everlasting [WL] [S1S2] [N]; Asteraceae
Pseudognaphalium obtusifolium (L.) Hilliard & Burtt — Sweet Everlasting [S5] [N]; Asteraceae as Gnaphalium obtusifolium -- 15 published photos
Ptelea trifoliata L. ssp. trifoliata var. trifoliata — Wafer-ash [SNA] [I]; Rutaceae -- 4 published photos
Pteridium aquilinum (L.) Kuhn var. latiusculum (Desv.) Underw. ex A. Heller — Bracken [S5] [N]; Dennstaedtiaceae -- 18 published photos
Pteridium aquilinum (L.) Kuhn var. pseudocaudatum (Clute) A. Heller — Pine Barrens Bracken [WL] [SNR] [N]; Dennstaedtiaceae
Ptilimnium capillaceum (Michaux) Raf. — Mock Bishop's-weed [S4] [N]; Apiaceae
Puccinellia distans (Jacq.) Parl. ssp. distans — European or Reflexed Alkali-grass [SNA] [I]; Poaceae as Puccinellia distans ssp. distans
Puccinellia maritima (Hudson) Parl. — Seaside Alkali-grass [S4] [N]; Poaceae -- 2 published photos
Puccinellia pumila (Vasey) A.S. Hitchc. — Northern Alkali-grass [H] [SH] [N]; Poaceae
Pueraria montana (Lour.) Merrill var. lobata (Willd.) Maesen & S. Almeida — Kudzu [likely invasive] [SNA] [I]; Fabaceae as Pueraria montana var. lobata -- 12 published photos
Pycnanthemum incanum (L.) Michaux var. incanum — Hoary Mountain-mint [S4] [N]; Lamiaceae -- 4 published photos
Pycnanthemum muticum (Michaux) Pers. — Short-toothed Mountain-mint [S4] [N]; Lamiaceae -- 23 published photos
Pycnanthemum tenuifolium Schrader — Slender-leaved Mountain-mint [S4] [N]; Lamiaceae -- 14 published photos
Pycnanthemum virginianum (L.) Durand & B.D. Jackson — Virginia Mountain-mint [S4] [N]; Lamiaceae
Pyrola americana Sweet — Glossy Shinleaf [S5] [N]; Ericaceae in Pyrolaceae -- 23 published photos
Pyrola chlorantha Sw. — Green Shinleaf [S4] [N]; Ericaceae in Pyrolaceae -- 4 published photos
Pyrola elliptica Nutt. — Elliptic Shinleaf [S5] [N]; Ericaceae in Pyrolaceae -- 9 published photos
Pyrus communis L. — Pear [SNA] [I]; Rosaceae -- 1 published photos
Quercus alba L. — White Oak [S5] [N]; Fagaceae -- 52 published photos
Quercus bicolor Willd. — Swamp White Oak [S4] [N]; Fagaceae -- 50 published photos
Quercus cerris L. — European Turkey-oak [SNA] [I]; Fagaceae
Quercus coccinea Muenchh. — Scarlet Oak [S5] [N]; Fagaceae -- 31 published photos
Quercus ilicifolia Wangenh. — Scrub-oak [S5] [N]; Fagaceae -- 55 published photos
Quercus montana Willd. — Chestnut-oak [S4] [N]; Fagaceae as Quercus prinus -- 22 published photos
Quercus prinoides Willd. — Dwarf Chinquapin-oak [S5] [N]; Fagaceae -- 43 published photos
Quercus robur L. — English Oak [SNA] [I]; Fagaceae -- 12 published photos
Quercus rubra L. — Red Oak [S5] [N]; Fagaceae -- 46 published photos
Quercus velutina Lam. — Black Oak [S5] [N]; Fagaceae -- 31 published photos
Quercus ×bimundorum Palmer [SNR] [I]; Fagaceae
Ranunculus abortivus L. — Kidney-leaf Buttercup [S5] [N]; Ranunculaceae -- 7 published photos
Ranunculus acris L. — Tall Buttercup [SNA] [I]; Ranunculaceae -- 4 published photos
Ranunculus aquatilis L. var. diffusus Withering — White Water-crowfoot [S5] [N]; Ranunculaceae
Ranunculus bulbosus L. — Bulbous Buttercup [SNA] [I]; Ranunculaceae -- 11 published photos
Ranunculus cymbalaria Pursh — Seaside Crowfoot [S4] [N]; Ranunculaceae
Ranunculus ficaria L. — Lesser Celandine [invasive] [SNA] [I]; Ranunculaceae -- 11 published photos
Ranunculus flabellaris Raf. — Yellow Water-crowfoot [S4] [N]; Ranunculaceae -- 4 published photos
Ranunculus pensylvanicus L. f. — Bristly Buttercup [SC] [S2] [N]; Ranunculaceae
Ranunculus recurvatus Poiret var. recurvatus — Hooked Buttercup [S5] [N]; Ranunculaceae -- 18 published photos
Ranunculus repens L. — Creeping Buttercup [likely invasive] [SNA] [I]; Ranunculaceae -- 11 published photos
Ranunculus sceleratus L. var. sceleratus — Cursed Crowfoot [WL] [S3?] [N?]; Ranunculaceae
Raphanus raphanistrum L. — Wild Radish [SNA] [I]; Brassicaceae -- 20 published photos
Rhamnus cathartica L. — Common Buckthorn [invasive] [SNA] [I]; Rhamnaceae -- 17 published photos
Rhexia virginica L. — Northern Meadow-beauty [S4] [N]; Melastomataceae -- 27 published photos
Rhinanthus alectorolophus (Scop.) Pollich — Large Yellow Rattle [SNA] [I]; Orobanchaceae
Rhododendron periclymenoides (Michaux) Shinners — Pinxter-flower [WL] [S2?] [N]; Ericaceae
Rhododendron vaseyi A. Gray — Vasey's Azalea [SNA] [W]; Ericaceae
Rhododendron viscosum (L.) Torrey — Swamp-azalea [S5] [N]; Ericaceae -- 16 published photos
Rhodora canadense (L.) Torrey [S4] [N]; Ericaceae as Rhododendron canadense -- 11 published photos
Rhodotypos scandens (Thunb.) Makino — Jetbead [SNA] [I]; Rosaceae -- 13 published photos
Rhus copallinum L. var. latifolia Engler — Winged Sumac [S4S5] [N]; Anacardiaceae as Rhus copallina -- 25 published photos
Rhus glabra L. — Smooth Sumac [S4S5] [N]; Anacardiaceae -- 15 published photos
Rhus hirta (L.) Sudworth — Staghorn-sumac [S5] [N]; Anacardiaceae as Rhus typhina -- 18 published photos
Rhynchospora alba (L.) Vahl — White Beak-rush [S5] [N]; Cyperaceae -- 12 published photos
Rhynchospora capitellata (Michaux) Vahl — Brown Beak-rush [S5] [N]; Cyperaceae -- 27 published photos
Rhynchospora fusca (L.) Aiton f. — Sooty Beak-rush [S5] [N]; Cyperaceae
Rhynchospora inundata (Oakes) Fern. — Inundated Horned-sedge [T] [S2] [N]; Cyperaceae -- 9 published photos
Rhynchospora macrostachya Torrey ex A. Gray — Big-headed Horned-sedge [S4] [N]; Cyperaceae -- 30 published photos
Rhynchospora nitens (Vahl) A. Gray — Short-beaked Bald-sedge [T] [S2] [N]; Cyperaceae -- 11 published photos
Rhynchospora scirpoides (Torrey) A. Gray — Long-beaked Bald-sedge [SC] [S3] [N]; Cyperaceae -- 39 published photos
Rhynchospora torreyana A. Gray — Torrey's Beak-sedge [E] [S1] [N]; Cyperaceae -- 8 published photos
Ribes hirtellum Michaux — Swamp-gooseberry [S4] [N]; Grossulariaceae -- 16 published photos
Ribes nigrum L. — European Black Currant [SNA] [I]; Grossulariaceae
Ribes rubrum L. — Garden Red Currant [SNA] [I]; Grossulariaceae -- 3 published photos
Robinia hispida L. var. hispida — Bristly Locust [SNA] [I]; Fabaceae -- 12 published photos
Robinia pseudoacacia L. — Black Locust [invasive] [SNA] [I]; Fabaceae -- 27 published photos
Robinia viscosa Vent. var. viscosa — Clammy Locust [SNA] [I]; Fabaceae
Rorippa palustris (L.) Besser var. fernaldiana (Butters & Abbe) R. Stuckey — Marsh Yellowcress [S4] [N]; Brassicaceae
Rorippa sylvestris (L.) Besser — Creeping Yellowcress [SNA] [I]; Brassicaceae
Rosa canina L. — Dog-rose [SNA] [I]; Rosaceae
Rosa carolina L. ssp. carolina — Pasture-rose [S5] [N]; Rosaceae -- 6 published photos
Rosa cinnamomea L. — Cinnamon-rose [SNA] [I]; Rosaceae
Rosa multiflora Thunb. ex Murray — Multiflora Rose [invasive] [SNA] [I]; Rosaceae -- 21 published photos
Rosa nitida Willd. — New England Rose [S4?] [N]; Rosaceae -- 11 published photos
Rosa palustris Marsh. — Swamp-rose [S5] [N]; Rosaceae -- 21 published photos
Rosa rubiginosa L. — Sweetbrier [SNA] [I]; Rosaceae as Rosa eglanteria
Rosa rugosa Thunb. — Saltspray Rose [SNA] [I]; Rosaceae -- 25 published photos
Rosa virginiana P. Miller — Low Rose [S5] [N]; Rosaceae -- 23 published photos
Rubus allegheniensis Porter — Common Blackberry [S5] [N]; Rosaceae -- 23 published photos
Rubus arenicola Blanchard — New England Sand-blackberry [S4] [N]; Rosaceae
Rubus argutus Link — Serrate Blackberry [S3?] [N]; Rosaceae
Rubus enslenii Tratt. — Southern Dewberry [S4] [N]; Rosaceae
Rubus flagellaris Willd. — Northern Dewberry [S5] [N]; Rosaceae -- 11 published photos
Rubus flagellaris Willd. × R. frondosus Bigelow [SNR] [N]; Rosaceae
Rubus hispidus L. — Bristly Dewberry [S5] [N]; Rosaceae -- 25 published photos
Rubus hispidus L. × R. semisetosus Blanch. [SNR] [N]; Rosaceae
Rubus idaeus L. ssp. strigosus (Michaux) Focke — Wild Red Raspberry [S5] [N]; Rosaceae as Rubus idaeus ssp. strigosus -- 8 published photos
Rubus jaysmithii Bailey — Smith's Blackberry [S4?] [N]; Rosaceae -- 5 published photos
Rubus occidentalis L. — Black Raspberry [S5] [N]; Rosaceae -- 12 published photos
Rubus odoratus L. — Purple-flowering Raspberry [S4] [I]; Rosaceae -- 12 published photos
Rubus pensilvanicus Poiret — Pennsylvania Blackberry [S5] [N]; Rosaceae
Rubus phoenicolasius Maxim. — Wineberry [likely invasive] [SNA] [I]; Rosaceae -- 8 published photos
Rubus pubescens Raf. — Swamp-dewberry [S5] [N]; Rosaceae -- 4 published photos
Rubus semisetosus Blanchard — Bog-blackberry [S4?] [N]; Rosaceae
Rubus semisetosus Blanch. × R. setosus Bigelow [SNR] [N]; Rosaceae
Rubus setosus Bigelow — Bristly Blackberry [S4] [N]; Rosaceae -- 6 published photos
Rubus vermontanus Blanchard — Vermont Blackberry [S4] [N]; Rosaceae
Rudbeckia hirta L. var. pulcherrima Farw. — Black-eyed Susan [SNA] [I]; Asteraceae as Rudbeckia hirta var. pulcherrima -- 8 published photos
Rumex acetosella ssp. pyrenaicus (Pourret ex Lapeyr.) Akeroyd — Sheep-sorrel [SNA] [I]; Polygonaceae -- 13 published photos
Rumex britannica L. — Great Water-dock [S4] [N]; Polygonaceae as Rumex orbiculatus -- 11 published photos
Rumex crispus L. ssp. crispus — Curly Dock [SNA] [I]; Polygonaceae -- 16 published photos
Rumex longifolius DC. — Dooryard Dock [SNA] [I]; Polygonaceae
Rumex obtusifolius L. ssp. obtusifolius — Bitter Dock [SNA] [I]; Polygonaceae -- 23 published photos
Rumex pallidus Bigelow — Seabeach Dock [T] [S2] [N]; Polygonaceae -- 4 published photos
Rumex triangulivalvis (Danser) Rech. f. — Willow-leaf Dock [SNA] [I]; Polygonaceae as Rumex salicifolius -- 4 published photos
Rumex verticillatus L. — Swamp-dock [T] [S1S2] [N]; Polygonaceae
Ruppia maritima L. — Widgeon-grass [S4S5] [N]; Ruppiaceae in -- 4 published photos
Sabatia campanulata (L.) Torrey — Slender Marsh-pink [E] [S1] [N]; Gentianaceae -- 7 published photos
Sabatia kennedyana Fern. — Plymouth Gentian [SC] [S3] [N]; Gentianaceae -- 42 published photos
Sagina procumbens L. — Matted Pearlwort [SNA] [I?]; Caryophyllaceae -- 12 published photos
Sagittaria engelmanniana J.G. Small — Engelmann's Arrowhead [S4] [N]; Alismataceae -- 8 published photos
Sagittaria filiformis J. G. Sm. — Riffle-arrowhead [S4] [N]; Alismataceae
Sagittaria graminea Michaux var. graminea — Grass-leaf Arrowhead [S4] [N]; Alismataceae -- 6 published photos
Sagittaria latifolia Willd. — Common Arrowhead, Duck-potato [S5] [N]; Alismataceae -- 17 published photos
Sagittaria subulata (L.) Buch. — River-arrowhead [H] [SH] [N]; Alismataceae
Sagittaria teres S. Watson — Pondshore- or Terete-arrowhead [SC] [S3] [N]; Alismataceae -- 47 published photos
Salicornia ambigua Michaux — Perennial Glasswort [S5] [N]; Amaranthaceae as Salicornia virginica in Chenopodiaceae -- 35 published photos
Salicornia bigelovii Torrey — Dwarf Glasswort or Saltwort [S4] [N]; Amaranthaceae in Chenopodiaceae -- 7 published photos
Salicornia depressa Standl. — Common Glasswort or Saltwort [S5] [N]; Amaranthaceae as Salicornia maritima in Chenopodiaceae -- 23 published photos
Salix alba L. — White Willow [SNA] [I]; Salicaceae -- 7 published photos
Salix bebbiana Sarg. — Long-beaked Willow [S5] [N]; Salicaceae -- 25 published photos
Salix cinerea L. ssp. cinerea — Gray Willow [SNA] [I]; Salicaceae -- 35 published photos
Salix discolor Muhl. — Large Pussy-willow [S5] [N]; Salicaceae -- 52 published photos
Salix eriocephala Michaux ssp. eriocephala var. eriocephala — Diamond-willow [S5] [N]; Salicaceae -- 50 published photos
Salix humilis Marsh — Small Pussy-willow, Prairie-willow, Upland-willow [S5] [N]; Salicaceae -- 56 published photos
Salix lucida Muhl. ssp. lucida — Shining Willow [S5] [N]; Salicaceae -- 14 published photos
Salix nigra Marsh. — Black Willow [S5] [N]; Salicaceae -- 41 published photos
Salix occidentalis Walt. — Dwarf Prarie Willow [S5] [N]; Salicaceae -- 51 published photos
Salix pedicellaris Pursh. — Bog-willow [WL] [S2?] [N]; Salicaceae -- 24 published photos
Salix petiolaris J. E. Smith — Slender Willow [S5] [N]; Salicaceae -- 31 published photos
Salix purpurea L. — Basket-willow [SNA] [I]; Salicaceae -- 4 published photos
Salix sericea Marsh. — Silky Willow [S5] [N]; Salicaceae -- 20 published photos
Salix ×conifera Wangenh. (pro sp.) [SNR] [N]; Salicaceae as Salix x conifera -- 9 published photos
Salsola kali L. ssp. pontica (Pallas) Mosyakin — Carolina Saltwort [S4] [N]; Amaranthaceae in Chenopodiaceae -- 27 published photos
Salsola kali L. ssp. kali — Prickly Saltwort, Seabeach-saltwort [S5] [N]; Amaranthaceae in Chenopodiaceae -- 27 published photos
Salsola tragus L. — Russian Thistle [SNA] [I]; Amaranthaceae
Sambucus nigra L. ssp. canadensis (L.) R. Bolli — Black Elderberry [S5] [N]; Adoxaceae as Sambucus canadensis in Caprifoliaceae -- 19 published photos
Sambucus racemosa L. — Red-berried Elderberry [S5] [N]; Adoxaceae as Sambucus racemosa ssp. pubens in Caprifoliaceae -- 3 published photos
Samolus valerandi L. ssp. parviflorus (Raf.) Hultén — Water-pimpernel [S4] [N]; Theophrastaceae
Sanguinaria canadensis L. — Bloodroot [S4] [I?]; Papaveraceae -- 17 published photos
Sanicula canadensis L. var. canadensis — Canadian Sanicle [T] [S2] [N]; Apiaceae
Santolina chamaecyparissus L. . — Lavender-cotton [SNA] [I]; Asteraceae
Saponaria officinalis L. — Soapwort [SNA] [I]; Caryophyllaceae -- 6 published photos
Sarracenia purpurea L. — Pitcher-plant [S5] [N]; Sarraceniaceae -- 16 published photos
Sassafras albidum (Nutt.) Nees [S5] [N]; Lauraceae -- 52 published photos
Schedonorus arundinaceus (Schreb.) Dumort. — Tall Rye Grass [SNA] [I]; Poaceae as Festuca arundinacea -- 4 published photos
Schedonorus pratensis (Hudson) Beauv. — Meadow Rye Grass [SNA] [I]; Poaceae as Festuca pratensis
Schizachyrium scoparium (Michaux) Nash var. scoparium — Little Bluestem [S5] [N]; Poaceae -- 20 published photos
Schoenoplectus americanus (Pers.) Volk. ex Schinz & R. Keller — Olney's Threesquare [S4] [N]; Cyperaceae as Scirpus americanus -- 5 published photos
Schoenoplectus pungens (Vahl) Palla var. pungens — Common Threesquare [S5] [N]; Cyperaceae as Scirpus pungens -- 6 published photos
Schoenoplectus purshianus (Fern.) M.T. Strong var. purshianus — Pursh's Bulrush [S4S5] [N]; Cyperaceae as Scirpus purshianus
Schoenoplectus smithii (A. Gray) Soják var. smithii — Smith's Club-sedge [S4] [N]; Cyperaceae
Schoenoplectus subterminalis (Torrey) Soják — Water Bulrush [S5] [N]; Cyperaceae as Scirpus subterminalis -- 15 published photos
Schoenoplectus tabernaemontani (K.C. Gmel.) Palla — Soft-stemmed Bulrush [S5] [N]; Cyperaceae as Scirpus tabernaemontani -- 15 published photos
Schoenoplectus torreyi (Olney) Palla — Torrey's Bulrush [WL] [S2?] [N]; Cyperaceae
Scirpus atrocinctus Fern. — Dusky Wool-grass [S5] [N]; Cyperaceae -- 1 published photos
Scirpus cyperinus (L.) Kunth — Wool-grass [S5] [N]; Cyperaceae -- 17 published photos
Scirpus georgianus Harper — Georgia Bulrush [S4?] [N]; Cyperaceae as Scirpus atrovirens var. georgianus -- 5 published photos
Scirpus hattorianus Makino — Meadow Bulrush [S5] [N]; Cyperaceae
Scirpus longii Fern. — Long's Wool-grass [T] [S2] [N]; Cyperaceae -- 2 published photos
Scirpus microcarpus J. & K. Presl — Red-stemmed Bulrush [S5] [N]; Cyperaceae
Scleranthus annuus L. — Annual Knawel [SNA] [I]; Caryophyllaceae -- 7 published photos
Scleranthus perennis L. — Perennial Knawel [SNA] [I]; Caryophyllaceae
Scleria reticularis Michaux — Pondshore Nut-sedge [WL] [S3] [N]; Cyperaceae -- 30 published photos
Scorzoneroides autumnalis (L.) Moench ssp. autumnalis — Fall-dandelion, Hawkbit [SNA] [I]; Asteraceae as Leontodon autumnalis -- 10 published photos
Scorzoneroides autumnalis (L.) Moench ssp. pratensis (Link) Holub — Fall-dandelion, Hawkbit [SNA] [I]; Asteraceae
Scrophularia lanceolata Pursh — American-figwort [S4?] [N]; Scrophulariaceae
Scrophularia nodosa L. — Wood-figwort [SNA] [I]; Scrophulariaceae -- 18 published photos
Scutellaria galericulata L. — Marsh-skullcap [S5] [N]; Lamiaceae -- 8 published photos
Scutellaria integrifolia L. — Hyssop Skullcap [H] [SH] [N]; Lamiaceae
Scutellaria lateriflora L. — Mad-dog Skullcap [S5] [N]; Lamiaceae -- 10 published photos
Secale cereale L. — Rye [SNA] [I]; Poaceae
Securigera varia (L.) Lassen — Crown-vetch [SNA] [I]; Fabaceae as Coronilla varia -- 2 published photos
Sedum acre L. — Wall-sedum [SNA] [I]; Crassulaceae -- 6 published photos
Sedum sarmentosum Bunge — Running Stonecrop [SNA] [I]; Crassulaceae
Selaginella apoda (L.) Spring — Meadow Spike-moss [S4?] [N]; Selaginellaceae
Selaginella rupestris (L.) Spring — Rock Spike-moss [WL] [S3S4] [N]; Selaginellaceae in -- 13 published photos
Senecio vulgaris L. — Common Groundsel [SNA] [I]; Asteraceae -- 4 published photos
Senna hebecarpa (Fern.) Irwin & Barneby — Northern Wild Senna [E] [S1] [N]; Fabaceae
Sericocarpus asteroides (L.) B.S.P. — Toothed White-topped Aster [S5] [N]; Asteraceae -- 13 published photos
Sericocarpus linifolius (L.) B.S.P. — Narrow-leaved White-topped Aster [S4] [N]; Asteraceae -- 13 published photos
Setaria faberi Herrm. ex Rosen — Nodding Foxtail [SNA] [I]; Poaceae -- 10 published photos
Setaria italica (L.) Beauv. — Foxtail-millet [SNA] [I]; Poaceae
Setaria parviflora (Poiret) Kerguelen — Bristly Foxtail [SC] [S3] [N]; Poaceae -- 4 published photos
Setaria pumila (Poir.) Roemer & J.A. Schultes ssp. pumila — Yellow Foxtail [SNA] [I]; Poaceae -- 16 published photos
Setaria viridis (L.) Beauv. — Green Foxtail [SNA] [I]; Poaceae -- 2 published photos
Sibbaldiopsis tridentata (Aiton) Rydb. — Three-toothed Cinquefoil [S4] [N]; Rosaceae -- 8 published photos
Sicyos angulatus L. — Bur-cucumber [S4] [N]; Cucurbitaceae -- 4 published photos
Silene antirrhina L. — Sleepy Catchfly [S4] [N]; Caryophyllaceae -- 7 published photos
Silene armeria L. — Sweet William Catchfly [SNA] [I]; Caryophyllaceae -- 9 published photos
Silene dichotoma Ehrh. — Forking Catchfly [SNA] [I]; Caryophyllaceae
Silene dioica (L.) Clairville — Red Campion [SNA] [I]; Caryophyllaceae -- 3 published photos
Silene latifolia Poir. ssp. alba (P. Mill.) Greuter & Burdet — Evening Lychnis [SNA] [I]; Caryophyllaceae as Silene latifolia ssp. alba -- 16 published photos
Silene noctiflora L. — Night-flowering Catchfly [SNA] [I]; Caryophyllaceae
Silene vulgaris (Moench) Garcke — Bladder-campion [SNA] [I]; Caryophyllaceae -- 6 published photos
Sinapis arvensis L. — Charlock [SNA] [I]; Brassicaceae
Sisymbrium altissimum L. — Tumbling Mustard [SNA] [I]; Brassicaceae -- 3 published photos
Sisymbrium officinale (L.) Scop. — Hedge-mustard [SNA] [I]; Brassicaceae -- 2 published photos
Sisyrinchium angustifolium P. Miller — Stout Blue-eyed Grass [S4] [N]; Iridaceae -- 14 published photos
Sisyrinchium atlanticum Bicknell — Eastern Blue-eyed Grass [S5] [N]; Iridaceae -- 4 published photos
Sisyrinchium montanum Greene var. crebrum Fern. — Meadow Blue-eyed Grass [S5] [N]; Iridaceae as Sisyrinchium montanum var. crebrum -- 6 published photos
Sium suave Walter — Water-parsnip [S5] [N]; Apiaceae -- 10 published photos
Smilax glauca Walter — Sawbrier [S5] [N]; Smilacaceae -- 20 published photos
Smilax herbacea L. — Carrion-flower [S5] [N]; Smilacaceae -- 10 published photos
Smilax rotundifolia L. — Common Greenbrier [S5] [N]; Smilacaceae -- 24 published photos
Solanum carolinense L. var. carolinense — Horse-nettle [SNA] [I]; Solanaceae -- 14 published photos
Solanum dulcamara L. var. dulcamara — Bittersweet Nightshade, Deadly Nightshade [SNA] [I]; Solanaceae -- 13 published photos
Solanum lycopersicon L. var. lycopersicon — Tomato [SNA] [I]; Solanaceae
Solanum ptycanthum Dunal — American Black Nightshade [S4S5] [N]; Solanaceae -- 7 published photos
Solanum rostratum Dunal — Buffalo-bur [SNA] [I]; Solanaceae
Solidago aestivalis Bicknell — Sphagnum-goldenrod [S4] [N]; Asteraceae
Solidago altissima L. ssp. altissima — Tall Goldenrod [S4] [N]; Asteraceae -- 10 published photos
Solidago bicolor L. — Silverrod [S5] [N]; Asteraceae -- 15 published photos
Solidago caesia L. var. caesia — Bluestem-goldenrod [S5] [N]; Asteraceae -- 5 published photos
Solidago canadensis L. var. canadensis — Canada Goldenrod [S5] [N]; Asteraceae -- 5 published photos
Solidago flexicaulis L. — Zigzag Goldenrod [S4S5] [N]; Asteraceae -- 5 published photos
Solidago gigantea Aiton — Late Goldenrod [S5] [N]; Asteraceae -- 12 published photos
Solidago juncea Aiton — Early Goldenrod [S5] [N]; Asteraceae -- 8 published photos
Solidago latissimifolia P. Miller — Elliott's Goldenrod [S4] [N]; Asteraceae -- 10 published photos
Solidago nemoralis Aiton ssp. nemoralis — Gray Goldenrod [S5] [N]; Asteraceae -- 13 published photos
Solidago odora Aiton ssp. odora — Sweet Goldenrod [S5] [N]; Asteraceae -- 16 published photos
Solidago puberula Nutt. var. puberula — Downy Goldenrod [S5] [N]; Asteraceae -- 11 published photos
Solidago rugosa P. Miller var. aspera (Aiton) Fern. — Rough Goldenrod [S4] [N]; Asteraceae as Solidago rugosa ssp. aspera -- 13 published photos
Solidago rugosa P. Miller var. rugosa — Rough-stemmed Goldenrod, Wrinkle-leaved Goldenrod [S5] [N]; Asteraceae -- 13 published photos
Solidago sempervirens L. ssp. sempervirens — Seaside-goldenrod [S5] [N]; Asteraceae -- 31 published photos
Solidago speciosa Nutt. var. speciosa — Showy Goldenrod [WL] [S2S3] [N]; Asteraceae -- 9 published photos
Solidago uliginosa Nutt. — Swamp-goldenrod [S5] [N]; Asteraceae -- 5 published photos
Solidago ulmifolia Muhl. ex Willd. var. ulmifolia — Elm-leaf Goldenrod [S4] [N]; Asteraceae
Solidago ×asperula Desf. [SNR] [N]; Asteraceae
Sonchus arvensis L. ssp. arvensis — Field Sow-thistle, Corn Sow-thistle [SNA] [I]; Asteraceae -- 9 published photos
Sonchus arvensis L. ssp. uliginosus (Bieber) Nyman — Swamp Sow-thistle [SNA] [I]; Asteraceae -- 9 published photos
Sonchus asper (L.) Hill — Spiny Sow-thistle [SNA] [I]; Asteraceae -- 1 published photos
Sonchus oleraceus L. — Annual Sow-thistle [SNA] [I]; Asteraceae -- 10 published photos
Sorbaria sorbifolia (L.) A. Braun — False Spiraea [SNA] [I]; Rosaceae
Sorbus aucuparia L. — European Mountain-ash [SNA] [I]; Rosaceae -- 6 published photos
Sorbus decora (Sarg.) Schneider — Showy Mountain-ash [E] [S1] [I]; Rosaceae
Sorghastrum nutans (L.) Nash — Indian Grass [S4S5] [N]; Poaceae -- 19 published photos
Sorghum bicolor (L.) Moench — sorghum [SNA] [W]; Poaceae
Sorghum halepense (L.) Pers. — Johnson-grass [SNA] [I]; Poaceae
Sparganium americanum Nutt. — Common Bur-reed [S5] [N]; Typhaceae in Sparganiaceae -- 22 published photos
Sparganium emersum Rehmann — Green-fruited Bur-reed [S4] [N]; Typhaceae as Sparganium erectum in Sparganiaceae -- 3 published photos
Sparganium eurycarpum Engelm. ex A. Gray — Giant Bur-reed [S3?] [N]; Typhaceae in Sparganiaceae -- 10 published photos
Spartina alterniflora Loisel — Saltwater Cord-grass [S5] [N]; Poaceae -- 20 published photos
Spartina cynosuroides (L.) Roth — Salt-reedgrass [T] [S2] [N]; Poaceae -- 5 published photos
Spartina patens (Aiton) Muhl. var. patens — Salt-hay, Salt-meadow Grass or Cord-grass [S5] [N]; Poaceae -- 18 published photos
Spartina pectinata Link — Prairie Cord-grass [S5] [N]; Poaceae -- 22 published photos
Spartina ×caespitosa A.A. Eaton [SNR] [N]; Poaceae
Spergula arvensis L. — Spurrey [SNA] [I]; Caryophyllaceae -- 21 published photos
Spergularia marina (L.) Griseb. — Saltmarsh Sand-spurrey [S4] [N]; Caryophyllaceae as Spergularia salina -- 14 published photos
Spergularia rubra (L.) J. & K. Presl — Red Sand-spurrey [SNA] [I]; Caryophyllaceae -- 10 published photos
Sphenopholis intermedia (Rydb.) Rydb. — Slender Wedgegrass [S4] [N]; Poaceae
Spinulum annotinum (L.) A. Haines — Bristly Clubmoss [S5] [N]; Lycopodiaceae as Lycopodium annotinum -- 7 published photos
Spiraea alba Du Roi var. latifolia (Aiton) Dippel — Meadowsweet [S5] [N]; Rosaceae as Spiraea alba var. latifolia -- 10 published photos
Spiraea tomentosa L. — Steeple-bush [S4] [N]; Rosaceae -- 15 published photos
Spiranthes cernua (L.) L. C. Rich. — Nodding Ladies'-tresses [S5] [N]; Orchidaceae -- 16 published photos
Spiranthes lacera (Raf.) Raf. var. lacera — Northern Slender Ladies'-tresses [S4] [N]; Orchidaceae
Spiranthes tuberosa Raf. — Little Ladies'-tresses [WL] [S3S4] [N]; Orchidaceae -- 9 published photos
Spirodela polyrrhiza (L.) Schleiden — Greater Duckweed [S5] [N]; Araceae as Spirodela polyrhiza in Lemnaceae -- 3 published photos
Sporobolus compositus (Poiret) Merrill var. compositus — Tall Dropseed [WL] [SNR] [I]; Poaceae
Sporobolus cryptandrus (Torrey) A. Gray — Sand-dropseed [WL] [S2?] [N]; Poaceae
Sporobolus vaginiflorus (Torrey ex A. Gray) Wood var. vaginiflorus — Poverty-grass [S5] [N]; Poaceae
Stachys arvensis (L.) L. — Corn-woundwort [SNA] [I]; Lamiaceae
Stachys hispida Pursh — Hispid Hedge-nettle [S4] [N]; Lamiaceae as Stachys tenuifolia
Stachys hyssopifolia Michaux — Hyssop Hedge-nettle [WL] [S3S4] [N]; Lamiaceae -- 21 published photos
Stachys palustris L. — Marsh Hedge-nettle, Clown's Woundwort [SNA] [I]; Lamiaceae -- 13 published photos
Stachys pilosa Nutt. var. pilosa — American Hedge-nettle [H] [SH] [N]; Lamiaceae
Stellaria alsine Grimm — Seep-starwort [S4?] [N]; Caryophyllaceae
Stellaria graminea L. — Common Stitchwort [SNA] [I]; Caryophyllaceae -- 6 published photos
Stellaria media (L.) Vill. — Common Chickweed [SNA] [I]; Caryophyllaceae -- 19 published photos
Strophostyles helvola (L.) Ell. — Beach-bean [S4] [N]; Fabaceae -- 7 published photos
Stuckenia pectinata (L.) Boerner — Sago-pondweed [S4] [N]; Potamogetonaceae -- 1 published photos
Suaeda calceoliformis (Hooker) Moq. — American Sea-blite [SC] [S2S3] [N]; Amaranthaceae
Suaeda linearis (Ell.) Moq. — Slender Sea-blite [S4] [N]; Amaranthaceae in Chenopodiaceae -- 12 published photos
Suaeda maritima (L.) Dumort. ssp. maritima — Saltmarsh Sea-blite [S4] [N]; Amaranthaceae in Chenopodiaceae -- 25 published photos
Suaeda maritima (L.) Dumort. ssp. richii (Fern.) Bassett & Crompton — Rich's Sea-blite [WL] [S2S3] [N]; Amaranthaceae as Suaeda richii in Chenopodiaceae
Swida alternifolia (L. f.) Small — Pagoda-dogwood [S5] [N]; Cornaceae as Cornus alternifolia -- 16 published photos
Swida amomum (P. Miller) Small var. amomum — Silky Dogwood [S5] [N]; Cornaceae as Cornus amomum -- 15 published photos
Swida racemosa (Lam.) Moldenke — Gray Dogwood [S5] [N]; Cornaceae as Cornus racemosa -- 7 published photos
Swida rugosa (Lam.) Rydb. — Round-leaved Dogwood [S4] [N]; Cornaceae as Cornus rugosa -- 6 published photos
Swida sanguinea (L.) Opiz — Red Dogwood [SNA] [W]; Cornaceae
Symphoricarpos orbiculatus Moench. — Coralberry [SNA] [I]; Caprifoliaceae
Symphyotrichum concolor (L.) Nesom var. concolor — Eastern Silvery Aster [E] [S1] [N]; Asteraceae
Symphyotrichum cordifolium (L.) Nesom — Blue Heart-leaf Aster [S4] [N]; Asteraceae as Aster cordifolius -- 9 published photos
Symphyotrichum dumosum (L.) Nesom — Bushy, Long-stalked Aster, Rice-button Aster [S5] [N]; Asteraceae as Aster dumosus -- 13 published photos
Symphyotrichum dumosum (L.) Nesom × S. racemosum (Ell.) Nesom [SNR] [N]; Asteraceae
Symphyotrichum ericoides (L.) Nesom var. ericoides — Heath-aster [S5] [N]; Asteraceae as Aster ericoides -- 11 published photos
Symphyotrichum lanceolatum (Willd.) Nesom ssp. lanceolatum var. lanceolatum — Tall White or Panicled Aster [S5] [N]; Asteraceae as Aster lanceolatus -- 6 published photos
Symphyotrichum lateriflorum (L.) A. & D. Löve — Calico Aster, Goblet-aster [S5] [N]; Asteraceae as Aster lateriflorus -- 5 published photos
Symphyotrichum novae-angliae (L.) Nesom — New England Aster [S5] [N]; Asteraceae as Aster novae-angliae -- 21 published photos
Symphyotrichum novi-belgii (L.) Nesom var. novi-belgii — New York Aster [S5] [N]; Asteraceae as Aster novi-belgii -- 32 published photos
Symphyotrichum patens (Aiton) Nesom var. patens — Skydrop Aster, Clasping Aster [S5] [N]; Asteraceae as Aster patens -- 10 published photos
Symphyotrichum pilosum (Willd.) Nesom var. pilosum — Hairy Aster, Awl-aster [S4?] [N]; Asteraceae as Aster pilosus -- 29 published photos
Symphyotrichum pilosum (Willd.) Nesom var. pringlei (A. Gray) Nesom — Pringle's Aster [S5] [N]; Asteraceae as Aster pilosus var. pringlei -- 8 published photos
Symphyotrichum puniceum (L.) A. & D. Löve var. puniceum — Bristly Aster, Swamp Aster [S5] [N]; Asteraceae as Aster puniceus -- 4 published photos
Symphyotrichum racemosum (Ell.) Nesom — Small White Aster [S4] [N]; Asteraceae as Aster racemosus -- 6 published photos
Symphyotrichum subulatum (Michaux) Nesom var. subulatum — Small-flowered Aster, Annual Saltmarsh-aster [S4] [N]; Asteraceae as Aster subulatus -- 10 published photos
Symphyotrichum tenuifolium (L.) Nesom var. tenuifolium — Large-flowered Aster [S4] [N]; Asteraceae as Aster tenuifolius -- 20 published photos
Symphyotrichum undulatum (L.) Nesom — Wavy-leaved Aster [S4S5] [N]; Asteraceae as Aster undulatus -- 10 published photos
Symplocarpus foetidus (L.) Salisb. ex Nutt. — Skunk-cabbage [S5] [N]; Araceae -- 17 published photos
Tagetes erecta L. — Aztec Marigold [SNA] [W]; Asteraceae
Tanacetum parthenium (L.) Schultz-Bip. — Feverfew [SNA] [I]; Asteraceae
Tanacetum vulgare L. — Tansy [SNA] [I]; Asteraceae -- 13 published photos
Taraxacum laevigatum (Willd.) DC. — Red-seeded Dandelion [SNA] [I]; Asteraceae -- 4 published photos
Taraxacum officinale G.H. Weber ex Wiggers — Dandelion [SNA] [I]; Asteraceae -- 10 published photos
Taxus baccata L. — English Yew [SNR] [I]; Taxaceae as Taxus sp. -- 5 published photos
Taxus canadensis Marsh. var. canadensis — American Yew [S5] [N]; Taxaceae -- 19 published photos
Teesdalia nudicaulis (L.) Aiton f. — Shepherd's Cress [SNA] [I]; Brassicaceae -- 36 published photos
Tephrosia virginiana (L.) Pers. — Goat's Rue [S4?] [N]; Fabaceae -- 12 published photos
Teucrium canadense L. var. canadense — Saltmarsh Germander, American Germander, Wood-sage [S4] [N]; Lamiaceae -- 11 published photos
Thalictrum dioicum L. — Early Meadow-rue [S5] [N]; Ranunculaceae -- 15 published photos
Thalictrum pubescens Pursh — Tall Meadow-rue [S5] [N]; Ranunculaceae -- 10 published photos
Thalictrum revolutum DC. — Skunk Meadow-rue [S4] [N]; Ranunculaceae -- 25 published photos
Thalictrum thalictroides (L.) Eames & Boivin — Rue-anemone [S3S4] [N]; Ranunculaceae
Thelypteris palustris Schott var. pubescens (Lawson) Fern. — Marsh-fern [S5] [N]; Thelypteridaceae -- 17 published photos
Thinopyrum pycnanthum (Pers.) Barkworth — Seabeach Quack-grass [SNA] [I]; Poaceae as Thinopyrum pycnanthum, Elytrigia pungens
Thlaspi arvense L. — Penny-cress [SNA] [I]; Brassicaceae -- 23 published photos
Thymus pulegioides L. — Wild Thyme [SNA] [I]; Lamiaceae
Tilia americana L. var. americana — Basswood, Whitewood, American Linden [S5] [N]; Malvaceae in Tiliaceae -- 18 published photos
Tilia cordata P. Miller — Small-leaved Linden [SNA] [I]; Malvaceae in Tiliaceae -- 2 published photos
Tilia ×vulgaris Hayne — Common Lime [SNA] [I]; Malvaceae as Tilia x vulgaris in Tiliaceae -- 2 published photos
Torreyochloa pallida (Torrey) Church var. fernaldii (A.S. Hitchc.) Dore ex Koyama & Kawano — Fernald's Mannagrass [S4] [N]; Poaceae as Torreyochloa pallida var. fernaldii -- 7 published photos
Torreyochloa pallida (Torrey) Church var. pallida — Pale or Torrey's Mannagrass [S5] [N]; Poaceae -- 1 published photos
Toxicodendron radicans (L.) Kuntze ssp. radicans — Poison-ivy [S5] [N]; Anacardiaceae -- 35 published photos
Toxicodendron vernix (L.) Kuntze — Poison-sumac [S5] [N]; Anacardiaceae as Rhus vernix -- 20 published photos
Tradescantia virginiana L. — Virginia Spiderwort [SNA] [I]; Commelinaceae -- 9 published photos
Tragopogon dubius Scop. — Pale Goat's Beard [SNA] [I]; Asteraceae
Tragopogon pratensis L. — Yellow Goat's Beard [SNA] [I]; Asteraceae -- 4 published photos
Triadenum virginicum (L.) Raf. — Marsh St. John's-wort [S5] [N]; Hypericaceae in Clusiaceae -- 15 published photos
Trichostema dichotomum L. — Blue Curls [S5] [N]; Lamiaceae -- 23 published photos
Tridens flavus (L.) A.S. Hitchc. var. flavus — Purpletop [SNA] [I]; Poaceae
Trifolium arvense L. — Rabbit-foot Clover [SNA] [I]; Fabaceae -- 8 published photos
Trifolium aureum Pollich — Palmate Hop-clover [SNA] [I]; Fabaceae as Trifolium agrarium -- 7 published photos
Trifolium campestre Schreber — Pinnate Hop-clover [SNA] [I]; Fabaceae
Trifolium hybridum L. — Alsike Clover [SNA] [I]; Fabaceae -- 4 published photos
Trifolium incarnatum L. — Crimson Clover [SNA] [I]; Fabaceae
Trifolium pratense L. — Red Clover [SNA] [I]; Fabaceae -- 6 published photos
Trifolium repens L. — White Clover [SNA] [I]; Fabaceae -- 10 published photos
Triglochin maritima L. — Saltmarsh Arrow-grass [S4] [N]; Juncaginaceae as Triglochin maritimum -- 19 published photos
Trillium cernuum L. var. cernuum — Nodding Trillium [S4S5] [N]; Melanthiaceae in Liliaceae -- 7 published photos
Trillium undulatum Willd. — Painted Trillium [S4] [N]; Melanthiaceae in Liliaceae -- 9 published photos
Triodanis perfoliata (L.) Nieuwl. — Venus's Looking-glass [S4] [N]; Campanulaceae -- 6 published photos
Triosteum aurantiacum Bicknell var. aurantiacum — Wild Coffee [S4] [N]; Caprifoliaceae
Triosteum perfoliatum L. — Broad Tinker's Weed [E] [S1] [N]; Caprifoliaceae
Triplasis purpurea (Walter) Chapman var. purpurea — Purple Sand-grass [S4] [N]; Poaceae -- 7 published photos
Tripsacum dactyloides (L.) L. — Northern Gama-grass [E] [S1] [N]; Poaceae
Tsuga canadensis (L.) Carr. — Eastern Hemlock [S4] [N]; Pinaceae -- 34 published photos
Tulipa sylvestris L. — Wild Tulip [SNA] [W]; Liliaceae
Tussilago farfara L. — Colt's-foot [likely invasive] [SNA] [I]; Asteraceae -- 26 published photos
Typha angustifolia L. — Narrow-leaved Cat-tail [S5] [N]; Typhaceae -- 12 published photos
Typha latifolia L. — Common Cat-tail [S5] [N]; Typhaceae -- 22 published photos
Ulmus americana L. — American Elm [S4] [N]; Ulmaceae -- 19 published photos
Ulmus glabra Hudson — Wych Elm [SNA] [I]; Ulmaceae -- 3 published photos
Ulmus procera Salisb. — English Elm [SNA] [I]; Ulmaceae -- 1 published photos
Urtica dioica L. ssp. dioica — Stinging Nettle [SNA] [I]; Urticaceae as Urtica dioica ssp. dioica -- 13 published photos
Urtica dioica L. ssp. gracilis (Aiton) Selander — Slender Stinging Nettle [S5] [N]; Urticaceae
Urtica urens L. — Burning-nettle [SNA] [I]; Urticaceae
Utricularia cornuta Michaux — Horned Bladderwort [S5] [N]; Lentibulariaceae -- 25 published photos
Utricularia geminiscapa Benj. — Twin-scaped Bladderwort [S4] [N]; Lentibulariaceae -- 10 published photos
Utricularia gibba L. — Humped Bladderwort [S5] [N]; Lentibulariaceae -- 2 published photos
Utricularia inflata Walter — Inflated Bladderwort [SNA] [I?]; Lentibulariaceae -- 16 published photos
Utricularia intermedia Hayne — Flat-leaved Bladderwort [S4S5] [N]; Lentibulariaceae -- 13 published photos
Utricularia macrorhiza Le Conte — Great Bladderwort [S5] [N]; Lentibulariaceae as Utricularia vulgaris -- 10 published photos
Utricularia purpurea Walter — Purple Bladderwort [S5] [N]; Lentibulariaceae -- 17 published photos
Utricularia radiata Small — Small Floating Bladderwort [S5] [N]; Lentibulariaceae -- 17 published photos
Utricularia resupinata B. D. Greene ex Bigelow — Resupinate Bladderwort [T] [S2] [N]; Lentibulariaceae -- 18 published photos
Utricularia subulata L. — Slender Bladderwort [SC] [S3] [N]; Lentibulariaceae -- 15 published photos
Uvularia sessilifolia L. — Wild Oats [S5] [N]; Colchiaceae in Liliaceae -- 17 published photos
Vaccaria hispanica (P. Miller) Rauschert — Cow-herb [SNA] [I]; Caryophyllaceae -- 4 published photos
Vaccinium angustifolium Aiton — Low Sweet Blueberry, Late Sweet Blueberry, Lowbush [S5] [N]; Ericaceae -- 16 published photos
Vaccinium caesariense Mackenzie — New Jersey Highbush Blueberry [SNR] [N]; Ericaceae
Vaccinium corymbosum L. — Highbush-blueberry [S5] [N]; Ericaceae -- 45 published photos
Vaccinium fuscatum Aiton — Black Highbush-blueberry [S5] [N]; Ericaceae -- 7 published photos
Vaccinium macrocarpon Aiton — Large Cranberry [S5] [N]; Ericaceae -- 32 published photos
Vaccinium oxycoccos L. — Small Cranberry [S4S5] [N]; Ericaceae
Vaccinium pallidum Aiton — Early Sweet Blueberry [S5] [N]; Ericaceae -- 29 published photos
Valeriana officinalis L. — Garden-valerian [SNA] [I]; Caprifoliaceae
Vallisneria americana Michaux — Tape-grass [S5] [N]; Hydrocharitaceae
Veratrum viride Aiton — False Hellebore [S5] [N]; Melanthiaceae in Liliaceae -- 14 published photos
Verbascum blattaria L. — Moth-mullein [SNA] [I]; Scrophulariaceae -- 6 published photos
Verbascum phlomoides L. — Clasping Mullein [SNA] [I]; Scrophulariaceae
Verbascum thapsus L. — Common Mullein [SNA] [I]; Scrophulariaceae -- 24 published photos
Verbena hastata L. var. hastata — Blue Vervain [S4] [N]; Verbenaceae -- 14 published photos
Verbena urticifolia L. — White Vervain [S5] [N]; Verbenaceae -- 13 published photos
Vernonia noveboracensis (L.) Michaux — New York Ironweed [S4] [N]; Asteraceae
Veronica americana Schwein. ex Bentham — American Brooklime [S4] [N]; Plantaginaceae
Veronica arvensis L. — Corn-speedwell [SNA] [I]; Plantaginaceae in Scrophulariaceae -- 12 published photos
Veronica austriaca L. ssp. teucrium (L.) D.A. Webb — Broad-leaved Speedwell [SNA] [I]; Plantaginaceae
Veronica chamaedrys L. — Birdseye-speedwell [SNA] [I]; Plantaginaceae in Scrophulariaceae -- 2 published photos
Veronica longifolia L. — Long-leaved-speedwell [SNA] [I]; Plantaginaceae
Veronica officinalis L. — Common Speedwell [SNA] [I]; Plantaginaceae in Scrophulariaceae -- 8 published photos
Veronica peregrina L. ssp. peregrina — Purslane-speedwell, Neckweed [S5] [N]; Plantaginaceae in Scrophulariaceae -- 3 published photos
Veronica peregrina L. ssp. xalapensis (Kunth) Pennell — Purslane-speedwell [S5] [N?]; Plantaginaceae in Scrophulariaceae -- 3 published photos
Veronica persica Poiret — Persian-speedwell [SNA] [I]; Plantaginaceae
Veronica scutellata L. — Marsh-speedwell [S5] [N]; Plantaginaceae in Scrophulariaceae
Veronica serpyllifolia L. ssp. serpyllifolia — Thyme-leaf Speedwell [SNA] [I]; Plantaginaceae in Scrophulariaceae -- 6 published photos
Viburnum acerifolium L. — Maple-leaf Viburnum [S5] [N]; Adoxaceae in Caprifoliaceae -- 15 published photos
Viburnum dentatum L. var. lucidum Aiton — Northern Arrow-wood [S5] [N]; Adoxaceae as Viburnum dentatum var. lucidum in Caprifoliaceae -- 10 published photos
Viburnum lantana L. — Wayfaring Tree [SNA] [W]; Adoxaceae in Caprifoliaceae -- 7 published photos
Viburnum lantanoides Michaux — Witch-hobble, Hobblebush [S5] [N]; Adoxaceae in Caprifoliaceae -- 12 published photos
Viburnum lentago L. — Nannyberry [S5] [N]; Adoxaceae in Caprifoliaceae -- 17 published photos
Viburnum nudum L. var. cassinoides (L.) Torrey & A. Gray — Wild Raisin [S5] [N]; Adoxaceae as Viburnum nudum var. cassinoides in Caprifoliaceae -- 28 published photos
Viburnum opulus L. ssp. opulus — Guelder Rose, Snowball [SNA] [I]; Adoxaceae in Caprifoliaceae -- 4 published photos
Vicia cracca L. ssp. cracca — Bird-vetch [SNA] [I]; Fabaceae -- 15 published photos
Vicia hirsuta (L.) S.F. Gray — Tiny Vetch [SNA] [I]; Fabaceae -- 3 published photos
Vicia sativa L. ssp. nigra (L.) Ehrh. Ehrh. — Narrow-leaved Vetch [SNA] [I]; Fabaceae as Vicia sativa ssp. nigra -- 8 published photos
Vicia tetrasperma (L.) Schreber — Four-seed Vetch [SNA] [I]; Fabaceae -- 7 published photos
Vicia villosa Roth — Hairy Vetch [SNA] [I]; Fabaceae
Vinca minor L. — Periwinkle [SNA] [I]; Apocynaceae -- 9 published photos
Viola arvensis Murray — Field-pansy [SNA] [I]; Violaceae
Viola blanda Willd. var. palustriformis A. Gray — Large-leaved White Violet [S4S5] [N]; Violaceae as Viola incognita -- 3 published photos
Viola brittoniana Pollard — Britton's Violet, Coast-violet [T] [S2] [N]; Violaceae -- 7 published photos
Viola cucullata Aiton — Blue Marsh-violet [S5] [N]; Violaceae -- 9 published photos
Viola labradorica Schrank — American Dog-violet [S4] [N]; Violaceae as Viola conspersa -- 10 published photos
Viola lanceolata L. ssp. lanceolata — Lance-leaf Violet [S5] [N]; Violaceae -- 25 published photos
Viola odorata L. — English Violet [SNA] [I]; Violaceae
Viola pallens (Banks ex DC.) Brainerd — Wild Violet [S5] [N]; Violaceae as Viola macloskeyi ssp. pallens -- 7 published photos
Viola pedata L. — Bird's Foot Violet [S5] [N]; Violaceae -- 28 published photos
Viola primulifolia L. — Primrose-leaf Violet [S?] [N]; Violaceae as Viola x primulifolia -- 7 published photos
Viola pubescens Aiton var. pubescens — Downy Yellow Violet [S4] [N]; Violaceae -- 4 published photos
Viola rotundifolia Michaux — Round-leaved Violet [S4] [N]; Violaceae
Viola sagittata Aiton var. ovata (Nutt.) Torrey & A. Gray — Arrow-leaf Violet [S5] [N]; Violaceae -- 27 published photos
Viola sororia Willd. — Common Blue Violet [S5] [N]; Violaceae as Viola sororia, Viola septentrionalis
Viola ×eclipes H.E. Ballard [SNR] [?]; Violaceae
Vitis aestivalis Michaux var. aestivalis — Summer-grape, Pigeon-grape [S4] [N]; Vitaceae -- 12 published photos
Vitis aestivalis Michaux var. bicolor Deam — Silver-leaved Grape [S5] [N]; Vitaceae -- 12 published photos
Vitis labrusca L. — Fox-grape [S5] [N]; Vitaceae -- 23 published photos
Vitis riparia Michaux — River-bank Grape [S4] [I]; Vitaceae -- 1 published photos
Vulpia octoflora (Walter) Rydb. var. tenella (Willd.) Fern. — Six-weeks Fescue [S4S5] [N]; Poaceae as Vulpia octoflora var. tenella -- 4 published photos
Wisteria floribunda (Willd.) DC. — Japanese Wisteria [SNA] [I]; Fabaceae -- 5 published photos
Wolffiella gladiata (Hegelm.) Hegelm. — Sickle Water-meal [WL] [SNR] [N]; Araceae
Woodsia ilvensis (L.) R. Br. — Rusty Woodsia [S5] [N]; Woodsiaceae in Dryopteridaceae
Woodwardia areolata (L.) T. Moore — Netted Chain-fern [S4] [N]; Blechnaceae -- 20 published photos
Woodwardia virginica (L.) Smith — Virginia Chain-fern [S4] [N]; Blechnaceae -- 18 published photos
Xanthium strumarium L. var. canadense (P. Miller) Torrey & A. Gray — Cocklebur [S5] [N]; Asteraceae as Xanthium echinatum -- 16 published photos
Xanthorhiza simplicissima Marsh. — Yellowroot [SNA] [I]; Ranunculaceae
Xyris difformis Chapman var. difformis — Yellow-eyed Grass [S5] [N]; Xyridaceae -- 10 published photos
Xyris smalliana Nash [WL] [S3?] [N]; Xyridaceae
Xyris torta Small — Twisted Yellow-eyed Grass [S4] [N]; Xyridaceae -- 19 published photos
Yucca filamentosa L. — Spanish Bayonet [SNA] [I]; Agavaceae -- 10 published photos
Zannichellia palustris L. — Horned Pondweed [S4] [N]; Zannichelliaceae
Zea mays L. ssp. mays — Corn [SNA] [W]; Poaceae
Zizania aquatica L. var. aquatica — Wild Rice [S4] [N]; Poaceae -- 14 published photos
Zizia aurea (L.) Koch — Golden Alexanders [S5] [N]; Apiaceae -- 6 published photos
Zostera marina L. — Eel-grass [S5] [N]; Zosteraceae

Draft 1.7 (2011-10-13 -- 2014-11-23)
Disclaimer. Due to possible parsing errors, county records may not always be accurate; the list may contain other errors, particularly within long names that include ssp. or vars. Matching has been performed mostly automatically or semi-automatically and has not yet been verified. The many-to-many relationship between names in the new Checklist and at Salicicola is not yet fully implemented. For example, Phellodendron amurense is not shown in darkred, because the Phellodendron occurring in the Boston area is treated as two different species at Salicicola: P. amurense and P. sachalinense, while in the Checklist it is a single species.