Branched glandular-pubescent stem. Stipules 3-12 mm long, foliaceous, much branched. Rachis (up to the last leaflet) 4-12 cm long, generally ending in a tendril, sometimes in a leaflet. Leaflets 8-22 (-30), 5-15 mm long, 3-8 mm broad, top rounded or truncate, base cuneate, pilose on both sides, upper half of the margin incised dentate, tip apiculate. Inflorescence 1(-2)-flowered, peduncle 2-10 cm long, ending in a spine. Flower pedicellate, pedicel 5-10 mm long. Calyx 10-12 mm long, pilose, tube very oblique, teeth subequal, 5-7 mm long. Corolla royal purple or white. Vexillum 20-25 mm long. Pod 20-30 mm long, 8-10 mm broad, beaked, many seeded.