Perennial climber or trailer. Stem oppressed pubescent when young. Leaf trifoliolate, petiole 4-16 cm long; Leaflets 6-18 cm long, 3.5-15 cm broad, ovate, obtuse to acuminate, pubescent on both surfaces; petiolule 7-10 mm long; stipules c. 2 mm long. Inflorescence a peduncled raceme, peduncle 12-28 cm long; pedicel c. 2 mm long; bracteoles c. 1 mm long. Calyx pubescent, tube 6-9 mm long; upper lip 4-5 mm long, rounded or emarginate. Vexillum mauve with white veins, 2.7-3.0 cm long. Fruit 10-17 cm long, 2.5-3 cm wide, linear-oblong, each valve with a sutural rib and an extra rib below this, densely brown pubescent.