Perennial climber, stem glabrous or pubescent. Leaf trifoliolate, petiole 1.5-19 cm long; leaflets 3-15 cm long, 1.2-10 cm broad, the lateral leaflets oblique, ovate to lanceolate or narrowly rhombic; acuminate, sparsely pubescent or glabrous; petiolules 3-5 mm long; stipules 2-3.5 mm long. Inflorescence a peduncled raceme; peduncle 1.5-30 cm long. Bracts 1.5 mm long, bracteoles 1.5-2.0 mm long. Pedicel 5-10 mm long. Calyx pubescent, tube 1.5-2.5 mm long, teeth 5-8 mm long, upper 2 joined to form an emarginate lip. Corolla white, yellowish or pale rose. Vexillum 5-7 mm long, sparsely pubescent or glabrous externally. Keel 10-14 mm long, spirally twisted for 1½ turns. Fruit 5-10.5 cm long, 1.2-2.5 cm broad, oblong-falcate or oblong, 3-4-seeded, glabrous or pubescent.