Northern Prairie Wildlife Research Center
The western two-thirds of North Dakota is home to plains sweet-broom. Elsewhere, the species occurs from Manitoba, Saskatchewan, and Oregon south to Texas and Arizona at elevations up to 9,500 ft.
Plains sweet-broom is perennial from a thickened base atop a heavy taproot. Plants have several-to-many stems about 12-20 inches tall. Most appear grayish-green due to a covering of short silvery hairs. Leaves are 2-3 inches long, with 7-13 leaflets about 1/2 inch long. Up to three dozen reddish-purple flowers are densely clustered atop stalks (peduncles) that arise near the tips of the stems. Flowers are about 5/8 inch long. Fruits are loments with 2-5 segments. A loment is a leguminous fruit constricted between the seeds, each 1-seeded segment separating at maturity. Seeds are dark brown and shiny.
Look for plains sweet-broom from June through August on dry native prairie. More plants are seen on grazed pastures, but grazing pressure seems to have little effect on the abundance of this plant in our area.
The sweet roots of the Hedysarums, often called "licorice-roots" are cooked for food by northern Amerindians. These roots are also said to be a principal food of brown bears. A European species is occasionally cultivated for cattle food. I found no mention of economic uses for the species discussed here.
The Hedysarums are members of the economically important bean family (Fabaceae). Fab means "bean" in Latin. The family includes our alfalfas, peas, clovers, peanuts, and trees such as caragana and locust. The generic name is from an old Greek name, hedusaron, for some plant. There are about 90 species in this genus; most are in Eurasia. The specific epithet boreale means "northern." The eminent English botanist-naturalist Thomas Nuttall (1786-1859) first described plains sweet-broom for science in 1818. Nuttall visited the Mandan villages along the Missouri River in 1810-1811.