Northern Prairie Wildlife Research Center
One of our most characteristic prairie plants, silver-leaf scurf pea should begin to bloom about this time of year. North Dakota is near the center of the range of this species, for it is restricted to the interior grassland region that extends from Alberta southward to New Mexico.
Silver-leaf scurf pea is easy to recognize because the leaves and stems are covered with hairs that give the plants a bright, silvery-gray color. The upper leaves have three leaflets and the lower five. Glandular dots or "scurf" can be seen on the leaflets under low magnification. One to three whorls of small blue flowers grow on stalks that arise from the points where the upper leaves join the stem. Silver-leaf scurf pea is a perennial that grows one to two feet tall from horizontal roots. At maturity, the hairy pods (legumes) are less than a quarter-inch long.
Look for this plant on the dry uplands in native prairie pastures. In our area, silver-leaf scurf pea seems to thrive best under moderate grazing by cattle.
This plant is a member of the bean family (Fabaceae) which is estimated to comprise about 10,000 species worldwide. About 75 species can be found in North Dakota. The family includes alfalfa, clover, pea, peanut, and hundreds of other economically important agricultural, medicinal, and ornamental herbs, shrubs, and trees. Fab means "bean" in Latin. The generic name Psoralea stems from the Greek psoraleos, "scabby," in ascription to the scurfy glandular dots on the leaves. Argophylla means "silvery- leaved" in botanical Latin. The renowned German botanist Frederick Pursh first described this species for science in 1814. Pursh was the first to publish upon the many plants brought back from the western wilderness by Lewis and Clark.