Index of plants by genus
| Species | Common Name | Family |
| Abies balsamea | Balsam Fir | Pinaceae |
| Acalypha gracilens | Slender Three-seeded Mercury | Euphorbiaceae |
| Acalypha rhomboidea | Common Three-seeded Mercury | Euphorbiaceae |
| Acer pensylvanicum | Striped Maple | Aceraceae |
| Acer negundo var. violaceum | Box Elder | Aceraceae |
| Acer nigrum | Black Maple | Aceraceae |
| Acer rubrum | Red Maple | Aceraceae |
| Acer saccharinum | Silver Maple | Aceraceae |
| Acer saccharum | Sugar Maple | Aceraceae |
| Acer spicatum | Mountain Maple | Aceraceae |
| Acorus americanus | American Sweet Flag | Acoraceae |
| Actea pachypoda | White Baneberry | Ranunculaceae |
| Actea rubra | Red Baneberry | Ranunculaceae |
| Adiantum pedatum | Maidenhair Fern | Pteridaceae |
| Adlumia fungosa | Allegheny Vine | Fumariaceae |
| Adoxa moschatellina | Muskroot | Adoxaceae |
| Aesculus glabra | Ohio Buckeye | Hippocastanaceae |
| Aesculus flava | Yellow Buckeye | Hippocastanaceae |
| Aesculus parviflora | Bottlebrush Buckeye | Hippocastanaceae |
| Aesculus pavia | Red Buckeye | Hippocastanaceae |
| Agalinis paupercula | Small-flowered False Foxglove | Orobanchaceae |
| Agalinis purpurea | Purple False Foxglove | Orobanchaceae |
| Agalinis setacea | Thread-leaved False Foxglove | Orobanchaceae |
| Agalinis tenuifolia | Slender False Foxglove | Orobanchaceae |
| Agastache foeniculum | Blue Giant Hyssop | Lamiaceae |
| Agastache nepetoides | Yellow Giant Hyssop | Lamiaceae |
| Agastache scrophulariifolia | Purple Giant Hyssop | Lamiaceae |
| Ageratina altissima | White Snakeroot | Asteraceae |
| Agrimonia gryposepala | Tall Agrimony | Rosaceae |
| Agrimonia parviflora | Swamp Agrimony | Rosaceae |
| Aletris farinosa | White Colicroot | Liliaceae |
| Alisma subcordatum | Southern Water Plantain | Alismataceae |
| Alisma triviale | Northern Water Plantain | Alismataceae |
| Allium canadense | Wild Garlic | Liliaceae |
| Allium cernuum | Prairie Onion | Liliaceae |
| Allium tricoccum | Wild Leek | Liliaceae |
| Alnus incana ssp. rugosa | Speckled Alder | Betulaceae |
| Alnus serrulata | Smooth Alder | Betulaceae |
| Alnus viridis | Mountain Alder | Betulaceae |
| Ambrosia artemisiifolia | Common Ragweed | Asteraceae |
| Ambrosia trifida | Giant Ragweed | Asteraceae |
| Amelanchier arborea | Serviceberry | Rosaceae |
| Amelanchier bartramiana | Mountain Shadbush | Rosaceae |
| Amelanchier canadensis | Canada Serviceberry | Rosaceae |
| Amelanchier humilis | Low Shadbush | Rosaceae |
| Amelanchier sanguinea | Round-leaved Serviceberry | Rosaceae |
| Amerorchis rotundifolia | Round-leaved Orchid | Orchidaceae |
| Ammophila breviligulata | Marram Grass | Poaceae |
| Amorpha canescens | Leadplant | Fabaceae |
| Amorpha glabra | Indigo Bush | Fabaceae |
| Amphicarpaea bracteata | Hog Peanut | Fabaceae |
| Amsonia tabernaemontana | Eastern Bluestar | Apocynaceae |
| Andromeda polifolia var. glaucophylla | Bog Rosemary | Ericaceae |
| Andropogon gerardii | Big Bluestem | Poaceae |
| Andropogon glomeratus | Bushy Bluestem | Poaceae |
| Andropogon scoparius | Little Bluestem | Poaceae |
| Andropogon virginicus | Broomsedge Bluestem | Poaceae |
| Anthoxanthum hirtum | Northern Sweet Grass | Poaceae |
| Anemone canadensis | Canada Anemone | Ranunculaceae |
| Anemone cylindrica | Thimbleweed | Ranunculaceae |
| Anemone patens var. wolfgangiana | Pasque Flower | Ranunculaceae |
| Anemone quinquefolia | Wood Anemone | Ranunculaceae |
| Anemone virginiana | Tall Thimbleweed | Ranunculaceae |
| Angelica atropurpurea | Great Angelica | Apiaceae |
| Anomodon attenuatus | Common Tree Apron Moss | Leskeaceae |
| Antennaria neglecta | Field Pussytoes | Asteraceae |
| Antennaria plantaginifolia | Plantain-leaved Pussytoes | Asteraceae |
| Anticlea elegans | Mountain Death Camas | Melanthiaceae |
| Apios americana | Ground Nut | Leguminosae |
| Apocynum androsaemifolium | Spreading Dogbane | Apocynaceae |
| Apocynum cannabinum | Indian Hemp, Dogbane | Apocynaceae |
| Aquilegia canadensis | Wild Columbine | Ranunculaceae |
| Arabis lyrata | Lyreleaf Rockcress | Brassicaceae |
| Aralia hispida | Bristly Sarsaparilla | Araliaceae |
| Aralia nudicaulis | Wild Sarsaparilla | Araliaceae |
| Aralia racemosa | Spikenard | Araliaceae |
| Aralia spinosa | Devil's Walkingstick | Araliaceae |
| Arceuthobium pusillum | Eastern Dwarf Mistletoe | Viscaceae |
| Arctostaphylos uva-ursi | Bearberry | Ericaceae |
| Arenaria caroliniana | Pinebarren Sandwort | Caryophyllaceae |
| Arenaria lateriflora | Bluntleaf Sandwort | Caryophyllaceae |
| Arenaria stricta | Stiff Sandwort | Caryophyllaceae |
| Arethusa bulbosa | Dragon's Mouth | Orchidaceae |
| Arisaema dracontium | Green Dragon | Araceae |
| Arisaema stewardsonii | Swamp Jack-in-the-Pulpit | Araceae |
| Arisaema triphyllum | Jack-in-the-Pulpit | Araceae |
| Aristida purpurascens | Arrowfeather Threeawn | Poaceae |
| Aronia arbutifolia | Red Chokeberry | Rosaceae |
| Aronia melanocarpa | Black Chokeberry | Rosaceae |
| Aronia prunifolia | Purple Chokeberry | Rosaceae |
| Artemisia caudata | Beach Wormwood | Asteraceae |
| Artemisia ludoviciana | Prairie Sage | Asteraceae |
| Aruncus dioicus | Goat's Beard | Rosaceae |
| Asarum canadense | Wild Ginger | Aristolochiaceae |
| Asclepias amplexicaulis | Clasping Milkweed | Asclepiacaceae |
| Asclepias exaltata | Poke Milkweed | Asclepiadaceae |
| Asclepias incarnata | Swamp Milkweed | Asclepiadaceae |
| Asclepias quadrifolia | Four-leaved Milkweed | Asclepiadaceae |
| Asclepias purpurascens | Purple Milkweed | Asclepiadaceae |
| Asclepias speciosa | Showy Milkweed | Asclepiadaceae |
| Asclepias syriaca | Common Milkweed | Asclepiadaceae |
| Asclepias tuberosa | Butterflyweed | Asclepiadaceae |
| Asclepias verticillata | Whorled Milkweed | Asclepiadaceae |
| Asclepias viridiflora | Short Green Milkweed | Asclepiadaceae |
| Asimina triloba | Papaw | Annonaceae |
| Asplenium platyneuron | Ebony Spleenwort | Aspleniaceae |
| Asplenium rhizophyllum | Walking Fern | Aspleniaceae |
| Asplenium ruta-muraria | Wall-rue | Aspleniaceae |
| Asplenium scolopendrium | American Hart's Tonguefern | Aspleniaceae |
| Asplenium trichomanes | Maidenhair Spleenwort | Aspleniaceae |
| Astragalus canadensis | Canadian Milk Vetch | Fabaceae |
| Athyrium angustum | Northern Lady Fern | Woodsiaceae |
| Atrichum angustatum | Lesser Smoothcap Moss | Polytrichaceae |
| Atrichum undulatum | Common Smoothcap Moss | Polytrichaceae |
| Aureolaria grandiflora | Large Yellow False Foxglove | Orobanchaceae |
| Aureolaria pedicularia | Fern-leaved False Foxglove | Orobanchaceae |
| Aureolaria virginica | Downy Yellow False Foxglove | Orobranchaceae |
© 2004-2009 Michael Hough