Small tree to 15 m tall. Leaves bipinnate, 1 pair of pinnae to 20 cm long, each with 2-3 pairs of opposite leaflets. Flowers greenish white to cream in small heads, grouped in branched clusters to 30 cm long on leaf axils of older stems. Fruits c. 25 cm long, spirally twisted or contorted, strap-shaped with swellings over seeds, dark brown to purple-brown.