Annual or perennial usually climbing herb; stems pilose with spreading to appressed hairs, later glabrescent. Leaflets 3, ± ovate, 1.2–10 x 1.1–6.5 cm, sometimes 3-lobed, appressed pilose. Stipules lanceolate, bilobed and unequally prolonged at the base. Flowers few to several on a rhachis 0.3–2 cm long; peduncle 1–45 cm long. Calyx glabrous or pubescent; tube 2–3 mm long; lobes 1.5–17 mm long, ciliate. Standard mauve to blue, 1–2.3 cm long, glabrous. Pods erect, linear-cylindrical, 30–95 x 2–3 mm, with short curved tubercle-based hairs, 14–25-seeded.