Perennial climbing or trailing herb 0.6–4 m long from a woody rootstock. Stems slender, finely pubescent to velvety. Leaflets 3, paler beneath, (2)4–9 × 0.8–3.7(4.5) cm, oblong, oblong-obovate or oblong-elliptic, rounded or emarginate and mucronulate at the apex, rounded or faintly subcordate at the base, sparsely appressed pubescent above, glabrescent to more densely appressed pubescent or velvety beneath; petioles 2–5 cm long; rhachis 0.5–1.5 cm long; petiolules 2–3 mm long; stipules 3–5 mm long, linear. Racemes lax, (1)2–10- or many-flowered, the flowers in groups of 1–3; rhachis 2–5(28) cm long; peduncles (3)7–17.5 cm long; pedicels 1.5–2 mm long; bracts and bracteoles (1.2)2–2.5 mm long, ovate-lanceolate. Calyx pubescent; tube 2.5–3 mm long; lobes 3.5–6(7) mm long, elliptic or elliptic-lanceolate, the lowest the longest. Standard whitish, pale lilac or pinkish-mauve and purple, 1–1.2 cm × 4–5 mm, elliptic or oblong-obovate, glabrous. Pods (1.5)3–6(8) cm × 4–7.5(10) mm, linear-oblong, finely appressed pubescent and sometimes also with long hairs, usually 6–12-seeded, but rarely 1-seeded (but not geocarpous) pods occur. Seeds yellowish-brown to dark blackish-red, mottled or suffused with grey, 3.5–5.5 × 2.5–3.5 × 2–2.5 mm.
