Hairy milk-vetch is a fairly attractive perennial wildflower with freely branched stems ascending or widely spreading from 10-40 cm long from a woody base. The stems and leaves are densely covered with grayish or white, long, tangled hairs throughout. The pinnately compound leaves bear from 15-29 elliptic-lanceolate, oblong or obovate leaflets which are rounded or tapered to a point at the tip. Individual leaflets measure from 8-14 mm long.
The flower stems are as long as or longer than the upper leaves and capped by a short, compact raceme of 6-19 flowers subtended by awl-shaped bracts. The racemes measure 1-3 cm long in bloom and from 6-8 cm long in fruit. The cylindrical calyx is 11-15 mm long, fairly densely haired (See photo at right.) with narrow teeth from 3-7 mm long. The purple corolla is 18-22 mm long with a white blotch on the banner with purplish veins. The narrow wings are slightly longer than the keel but shorter than the banner. The banner is also hairy on the back (barely visible on the photo at right.). The spreading, densely woolly pods measure from 15-30 mm long and are abruptly curved or arched above the middle.
Hairy Milk-vetch: Astragalus inflexus - Foliage densely whitish pubescent. Ascending stems from 10-40 cm long. Purplish corolla 18-22 mm long. Found from both shores of the Columbia River to the east of Rock Creek and north into central Washington and east to western Montana.
Newberry's Milk-vetch: Astragalus newberryi - Foliage densely silvery pubescent or with satiny, appressed hairs. Leaflets broadly obovate. Whitish, yellowish, or commonly pink or purplish corolla 20-25 mm long. In our area, found from Crook County in central Oregon south to southeastern Oregon, Nevada and California.
Pursh's Milk-vetch: Astragalus purshii - Foliage densely whitish pubescent. Depressed stems from 0-10 cm long. Purplish corolla 25-30 mm long. Found across much of central and eastern Washington and Oregon.
Hairy milk-vetch is found among sagebrush in the basin valleys and hillsides.
Hairy milk-vetch is found from central Washington south to northern oregon and east to the Snake River Canyon of southeastern Washington and northeastern Oregon and hence east to western Montana.
In the Columbia River Gorge, it may be found near the elevations of 200'-300' east of Roosevelt, WA and near Arlington, Or and eastward towards Umatilla, OR.