A trailing herb. It grows 3-15 m long. The stems are flattened and have rusty hairs. The leaflets are 6-17 cm long by 4-12 cm wide. They are oval and taper towards the tip. There are soft hairs on both surfaces. The flower clusters are 18-50 cm long. The fruit are pods 10-17 cm long by about 3 cm wide. The pods are densely hairy at first. The seeds are brown. They are 16-20 mm long by 7-11 mm wide.
Leaflets 6–17(23) × 4–12(15) cm, ovate, acuminate to a short blunt tip or elsewhere rarely rounded, sparsely to densely pubescent on both surfaces; petiole 4–13(16) cm long; stipules c. 2 mm long, rather thick.
Pods 10–17 × 2.5–3 cm, linear-oblong, each valve with a sutural rib and an extra rib just below this, densely ferruginous pubescent at first, later somewhat glabrescent.
Standard mauve with white veins and green towards the base, 2.7–3 × 1.7 cm, oblong; wings and keel mauve, white towards the base.
Inflorescences 18–50 cm long, long-pedunculate; pedicels 2 mm long; bracteoles just over 1 mm long, obtuse.
Seeds brown or reddish-brown, sometimes marbled with black, 16–20 × 11–20 × 7–11 mm; hilum 11–15 mm long.
Calyx pubescent; tube 6–9 mm long; upper lip 4–5 mm long, rounded or emarginate.
Stems appressed ferruginous pubescent, glabrescent.
Perennial climber, or stems trailing, 3–15 m long.