Tall shrubs sometimes seen as up to 6 m high, with a flat-top canopy. Branches yellowish-brown. Stipular spines of two kinds; the long ones up to 6 cm, white, brown-tiped, the short usually 1 cm or less, more or less falcate or hooked downwards, reddish dark-brown or the lower parts white. Leaves borne in axillary clusters, densely pubescent; pinna-pairs usually 2-6, each pinna with usually 6-12 pairs of leaflets : rachii sparingly or densely pubescent, each with usually 2 sessile glands and ending in a short appendage beyond the last pinna-pairs, leaflets minute, rarely exceeding 3 mm in length. Flowers in white to creamy-white globular heads about 8 mm across; peduncles about 1.5 cm long : involucel almost at the base of the peduncle. Calyx about 1.5 mm. Corolla about 2.5 mm long, 5-lobed, glabrous. Pods most often spirally contorted or twisted, green, reddish-tinged, densely pubescent, up to 15 cm long, usually 5 mm or less wide, often constricted between seeds.