Northern Prairie Wildlife Research Center
The first flowers of groundplum or "buffalo bean" appear about this time of the year in North Dakota. This plant is one of our most common wild legumes, and occurs on native prairies from Manitoba to Saskatchewan south to New Mexico and Texas.
Look for groundplum milk-vetch on pastures that do not have a long history of overgrazing, because the plant is readily consumed by livestock. The showy pinkish to bluish-purple flowers are three-quarters of an inch long, and occur in dense clusters of five to fifteen. At first the 4 to 12-inch stems are upright, but as the fleshy reddish legumes (pods) develop in June, the stems bend to the ground. Leaves of this perennial plant have fifteen to thirty narrow leaflets arranged on a central axis like two combs held back-to-back.
The pods of groundplum milk-vetch were eaten raw or boiled by native Americans. However, readers are cautioned not to eat wild legumes without positive identification because some may be poisonous.
The generic name Astragalus is an ancient Greek name for some member of the bean family (Fabaceae). Fab means "bean" in Latin. The genus contains about 1500 species. The specific epithet crassicarpus was compounded from the Latin by botanists to mean "thick-fruited." Groundplum milk-vetch was discovered by the renowned English naturalist Thomas Nuttall (1786-1859). He visited the Mandan villages in what is now North Dakota in 1810.