Tree, up to 20 m tall. Bark in young tree smooth and ash coloured becoming rough and dark brown in old. Stipules deltoid, acute, 1-2 mm long, caducous. Rachis 12-25 cm long, terete, glabrous. Leaves compound 22.5-40 cm long, with 3-8 pairs of opposite leaflets, 6-10 (20) cm long, smooth above, hairy below. Flowers arranged in drooping racemes, each raceme c. 10-45 cm long; peduncle 2-10 cm long. Pedicel 3.7-5.8 cm long, slender, slightly hairy or quite smooth, bracts 8-10 mm long, ovate, acute, hairy. Calyx 5, green, folded backward on the stalk, hairy, ovate, 9 mm long. Petals 5, obovate, blunt, distinctly veined. Stamens 10, 3 longest stamens much curled and bear large oblong anthers, 4 smaller medium ones are quite straight, 3 remaining stamens are quite short, erect and sterile. Ovary slender, thinly appressed hairy, style sturdy, stigma punctiform. Pods terete, glabrous, indehiscent, 40-60 cm long, 1.5-2 cm broad, black glossy brown, 40-100 seeded.