Perennial herb from a taproot and branching stem-base; stems prostrate, tufted or mat-forming, 5-10 cm long, greyish-woolly with unbranched hairs.
Alternate, pinnately compound, crowded, 2-15 cm long, white-woolly; leaflets 5 to 19, elliptic or oval to oblong, 5-20 mm long; stipules membranous, lanceolate, long-pointed, 3-15 mm long, usually exceeding the internodes, not joined at the base.
Inflorescence a short, axillary raceme of 2 to 10 pea-like flowers, the raceme-stalks from shorter to longer than the leaves, sometimes almost lacking, arching or lying on the ground in fruit; corollas yellowish-white to reddish-purple, 1-3 cm long, the banner longer than the wings and the blunt keel; calyces cylindric, 12-16 mm long, black- to grey-hairy, the narrowly lanceolate teeth 1/3-1/2 as long as the tube.
Pods, egg-shaped or narrowly ellipsoid, spreading, unstalked, 1-2.5 cm long, leathery, greyish-woolly, somewhat flattened, straight to curved, 1-chambered.
Two intergrading varieties of this highly variable species are recognized in BC.
1. Flowers yellowish-white or pale lavender, the keels purple-tipped; pods nearly straight.................. var. purshii
1. Flowers reddish-purple; pods curved and strongly grooved............... var. glareosus (Dougl. ex Hook.) Barn.
Source: The Illustrated Flora of British Columbia