General: Perennial herb from a branched, woody stem-base and heavy taproot; stems several, erect, 40-80 cm tall, branched above, sparsely short-hairy.
Leaves: Alternate, odd-pinnate, mostly glabrous, sometimes thinly short-hairy below, minutely gland-dotted on the upper surface; leaflets 9 to 21, lanceolate to elliptic, conspicuously veined, 10-40 mm long; stipules membranous, brownish, lower ones joined, up to 3 cm long, upper ones usually free.
Flowers: Inflorescence an axillary, often one-sided raceme of 20 to 80 pea-like, nodding flowers; corollas reddish-purple, 16-22 mm long, the wing lobes linear and nearly equal to the claw; calyces 4-5 mm long, short-hairy, the teeth shorter than the tube, the upper pair of teeth wider and shorter than the lower three.
Fruits: Pods, constricted between the seeds into (1) 2 to 4 segments, the segments egg-shaped to elliptic, 7-12 mm wide, delicately and irregularly net-veined, the margins winged, 1-2 mm wide.
