Large, prickly shrub or small tree; branches straggling, reddish brown when young, slender, grooved, finely downy, thickly beset with short, recurved, sharp, hooked spines; leaves bipinnate with prickly deflexed rachis; stipules subulate; pinnae 4-10 pairs with a bristle like gland between each pair, obliquely cuspidate, membranous, opposite; leaflets 4-12 pairs, linear-oblong, obtuse, pubescent below; flowers pink, fading to white, in solitary or fascicled heads on short, axillary peduncles; stamens 8-10, twice as the number of petals, much exerted; filaments filiform, free, anthers minute; ovary stalked, many ovuled, style filiform, stigma capitate, minute; pods 8-10 cm, 6-10 seeded, linear-oblong, glabrous, jointed, strap or ribbon shaped, slightly falcate, smooth, sutures rarely furnished with few distant prickles.