Shrub or small tree 1–7 m. high, deciduous; bark dark dull brown or red. Young branchlets glabrous, becoming blackish. Leaves up to 42 cm. long, glabrous or nearly so; pinnae 4–31 pairs; leaflets 12–48 pairs, linear to narrowly oblong, 3.5–12 mm. long, 0.7–3 mm. wide, glabrous; midrib starting at distal corner of leaf-base, gradually becoming almost central in the leaf; proximal side of base rounded and almost auriculate; apex acute and nearly symmetrical; lateral nerves and veins not or scarcely visible. Racemes glabrous, 5–22 cm. long; pedicels 1–2 mm. long. Flowers variously described as yellow, or with brownish-violet petals and yellow stamens. Calyx 1–1.5 mm. long. Petals 2.5–3 mm. long. Stamen-filaments about 5 mm. long. Pods linear-oblong, up to 44 cm. long and 2–3 cm. wide, the seeds showing as bumps at intervals. Seeds lenticular, 16–20 mm. long, 14–18 mm. wide and 10–12 mm. thick. Fig. 4, p. 20.