This flora list represents 102 of the more common plants found in Theodore Roosevelt National Park. Over 400 plants have been located and identified within the park and it is estimated that perhaps as many as 500 different species exist. Please respect other park visitors as well as wildlife when viewing wildflowers. Picking or collecting plants is prohibited.
Plants listed can be found in one or all three units of the park. Common names shown are those used in this region. Scientific names follow the convention used in Flora of the Great Plains published in 1986 by University Press of Kansas unless later accepted changes have been made. Flowering date represents the best period of time to see the plant in bloom under normal conditions. Dates could be altered by weather. Space permits listing only primary habitat.
| Grasses | | | |
| Common Name | Scientific Name | Family | Habitat |
| Big sandgrass | Calamovilfa longifolia | Grass | Sandy setting |
| Blue grama | Bouteloua | Grass | Prairie |
| Buffalo grass | Buchloe dactyloides | Grass | Uplands |
| Canada wild rye | Elymus canadensis | Grass | Riverbottom/channels |
| Crested wheatgrass | Agropyron cristatum | Grass | Roadsides |
| Foxtail barley | Hordeum jubatum | Grass | Alkaline settings |
| Green needlegrass | Stipa viridula | Grass | Prairie |
| Junegrass | Koeleria pyramidata | Grass | Prairie |
| Kentucky bluegrass | Poa pratensis | Grass | Campground |
| Little bluestem | Andropogon scoparius | Grass | Ridge slopes |
| Needle-and-thread | Stipa comata | Grass | Prairie |
| Threadleaf sedge | Carex filifolia | Sedge | Prairie uplands |
| Saltgrass | Distichlis spicata stricta | Grass | Alkaline settings |
| Sideoats grama | Bouteloua curtipendula | Grass | Ridge slopes |
| Smooth brome | Bromus inermis | Grass | Roadsides |
| Western wheatgrass | Agropyron smithii | Grass | Uplands |
| (state grass) |
| Shrubs | | | Flowering | Flower |
| Common Name | Scientific Name | Family | Time | Color |
| Big sage/ Three-toothed sage | Artemisia tridentata | Aster | | |
| Buckbrush/Wolfberry | Symphoricarpos occidentalis | Honeysuckle | June-July | White |
| Buffaloberry/Bullberry | Shepherdia argentea | Oleaster | | |
| Choke cherry | Prunus virginiana | Rose | May-June | White |
| Common/Shrub juniper/ cedar | Juniperus communis | Cypress | | |
| Creeping juniper/cedar | Juniperus horizontalis | Cypress | | |
| Skunkbush/Fragrant sumac | Rhus aromatica | Cashew | May-June | Yellow |
| Golden/Buffalo currant | Ribes odoratum | Currant | May | Yellow |
| Greasewood | Sarcobatus vermiculatus | Goosefoot | | |
| Juneberry/Saskatoon | Amelanchier alnifolia | Rose | | |
| Poison ivy | Toxicodendron rydbergii | Cashew | | |
| Prairie rose (state flower) | Rosa arkansana | Rose | June-July | Pink |
| Rabbitbrush | Chrysothamnus nauseosus | Aster | Aug-Sept | Yellow |
| Sandbar willow | Salix interior | Willow | | |
| Shrubby cinquefoil/ Potentilla | Potentilla fruiticosa | Rose | June-Aug | Yellow |
| Silver sage | Artemisia cana | Aster | | |
| Spiny saltbush | Atriplex confertiflora | Goosefoot | | |
| Wild plum | Prunus americana | Rose | May | White |
| Winterfat | Ceratoides lanata | Goosefoot | | |
| Wood's rose | Rosa woodsii | Rose | June | Pink |
| Trees | | | |
| Common Name | Scientific Name | Family | Habitat |
| American elm | Ulmus americana | Elm | Riverbottom, draws |
| Box elder | Acer negundo | Maple | Riverbottom |
| Cottonwood | Populus deltoides | Willow | Riverbottom |
| Green ash | Fraxinus pennsylvanica | Olive | Draws, riverbottom |
| Rocky Mountain juniper/cedar | Juniperus scopulorum | Cypress | North-facing slopes |
| Herbs | | | Flower |
| Common Name | Scientific Name | Family | Color |
| Aromatic aster | Aster oblongifolius | Aster | Purple |
| Bastard toadflax | Comandra umbellata | Sandalwood | White |
| Bergamot/Beebalm | Monarda fistulosa | Mint | Pink |
| Blazing star/ Dotted gayfeather | Liatris aspera | Aster | Purple |
| Blue wild lettuce | Lactuca oblongifolia | Aster | Purple |
| Snakeweed | Gutierrezia sarothrae | Aster | Yellow |
| Butte candle | Cryptantha celosioides | Borage | White |
| Common sunflower | Helianthus annuus | Aster | Yellow |
| Crested beardtongue | Penstemon eriantherus | Figwort | Purple |
| Curlycup gumweed | Grindelia squarrosa | Aster | Yellow |
| False Solomon's seal | Smilacina stellata | Lily | White |
| Fetid marigold | Dyssodia papposa | Aster | Yellow |
| Field bindweed | Convolvulus sepium | Morning Glory | White |
| Fringed sage | Artemisia frigida | Aster | Yellowish |
| Goat's beard/ Western salsify | Tragopogon dubius | Aster | Yellow |
| Golden aster | Chrysopsis villosa | Aster | Yellow |
| Golden pea | Thermopsis rhombifolia | Pea | Yellow |
| Goldenrod | Solidago spp. | Aster | Yellow |
| Ground plum | Astragalus crassicarpus | Bean | Pink |
| Gumbo lily | Oenothera caespitosa | Primrose | White |
| Harebell | Campanula rotundifolia | Bellflower | Purple |
| Henbane | Hyoscamus niger | Potato | Greenish |
| Indian breadroot/ Tipsin | Psoralea esculenta | Pea | Purple |
| Indian paintbrush | Castilleja sessiliflora | Figwort | Yellow |
| Large-flowered dock | Rumex venosus | Buckwheat | Pink |
| Leafy spurge | Euphorbia esula | Spurge | Greenish |
| Leopard lily | Fritillaria atropurpurea | Lily | Purple |
| Moss phlox | Phlox hoodii | Phlox | White |
| Northern bedstraw | Galium boreale | Madder | White |
| Pincushion cactus | Coryphantha vivipara | Cactus | Red |
| Prickly pear cactus | Opuntia polyacantha | Cactus | Yellow |
| Prince's plume | Stanleya pinnata | Mustard | Yellow |
| Purple coneflower | Echinacea augustifolia | Aster | Purple |
| Purple locoweed | Oxytropis lambertii | Pea | Purple |
| Purple prairie clover | Dalea purpurea | Pea | Purple |
| Pussytoes | Antennaria spp. | Aster | White |
| Scarlet/ Red globe mallow | Sphaeralcea coccinea | Mallow | Red |
| Rocky Mountain bee plant | Cleome serrulata | Caper | Pink |
| Scoria lily/ Evening star | Mentzelia decapetala | Stickleaf | White |
| Sago/Mariposa lily | Calochortus nuttallii | Lily | White |
| Scarlet gaura | Gaura coccinea | Primrose | White/red |
| Showy milkweed | Asclepias speciosa | Milkweed | Pink |
| Silver-leaf scurf pea | Psoralea argophylla | Pea | Purple |
| Skeletonweed | Lygodesmia juncea | Aster | Pink |
| Spreading dogbane | Apocynum androsaemifolium | Dogbane | White |
| Stiff sunflower | Helianthus rigidus | Aster | Yellow |
| Tumbling mustard | Sisymbrium altissimum | Mustard | Yellow |
| Wavy-leaf thistle | Circium undulatum | Aster | Purple |
| Western virgin's bower | Clematis ligusticifolia | Buttercup | White |
| Western wallflower | Erysimum asperum | Mustard | Yellow |
| White beardtongue/ penstemon | Penstemon albidus | Figwort | White |
| White sage | Artemisia ludoviciana | Aster | |
| White sweet clover | Melilotus alba | Pea | White |
| White wild onion/Prairie onion | Allium textile | Lily | White |
| Whorled milkweed | Asclepias verticillata | Milkweed | White |
| Crocus/Pasque flower | Anemone patens | Buttercup | Purple |
| Wild licorice | Glycyrrhiza lepidota | Pea | Yell/white |
| Wooly plantain | Plantago patagonica | Plaintain | |
| Yarrow | Achillea millefolium | Aster | White |
| Yellow buckwheat/ umbrella plant | Eriogonum flavum | Buckwheat | Yellow |
| Yucca | Yucca glauca | Lily | White |
