Nineteenth-century atlases called the plains the Great American Desert, an undeserved name that ignores the subtle variety of the grasses and plants found here. While the prairie is not known for its trees, the savannas of eastern Montana offer more than sagebrush and prickly pear landscapes. Willows take root in the river valleys, and Lewis and Clark noted a “scattering of pine and cedar” on the hills, and chokecherries and currants on lower ground. The cottonwoods that grow near river bottoms were prized for firewood and for dugout canoes.

Eastern Montana is mostly short-grass prairie—that is, a dry grassland supporting perennial grasses such as bluestem, bluejoint, bluegrama, June, wheat, and pine grass. Cheat grass grows in overgrazed areas; it starts strong but can’t last through the summer. Other “nuisances” are feather grass and needle grass, which irritate the skin and eyes of sheep and cattle. Russian thistle, or tumbleweed, arrived with European immigrants and is almost universally reviled for its uselessness and prolific nature.

Prairie flowers include the buttercup, yellowbell, crocus, shooting star, bluebell, blanketflower, golden aster, and daisy. Blue camas and death camas grow in moist areas. Prickly pear and three other species of cactus still dog those who try to walk across the prairie. Milkweed, a common roadside plant, was variously used as eye medicine, gravy stock, and chewing gum by the Cheyenne. The deep thick roots of the Indian breadroot plant were an important food for eastern Montana Indians.

Chokecherry bushes are widespread on the northern plains and into the Rockies. Chokecherries were pounded, dried, and stored for the winter by Plains Indians. Indians also brewed a tea from the bark to relieve stomach ailments; unripe chokecherry purée was used by both Indians and white settlers to treat diarrhea.

Prairie sage is a traditional sacred and medicinal plant to many Montana Indians.