Attaining about 20 ft.; extremities pubescent or glabrous. Infra-stipular spines short, dilated at the base, usually slightly recurved at the apex, frequently wanting; occasionally similar thinly scattered spines occur on the internodes. Leaf-rachis usually puberulous, sometimes aculeolate bearing a sessile gland near the base, 2–4 in. long; pinnæ in 6–14 pairs; leaflets linear-oblong, broadly pointed or obtuse, 2 lines long, and 1/2 line broad more or less, in 20–40 pairs. Spikes dense, shortly pedunculate, solitary or in fascicles of 2 or 3, shorter than or occasionally exceeding the leaves. Flowers sessile. Calyx cupuliform, teeth 1/3– 1/2 its depth. Petals narrowed and free at the base, united at the middle; but slightly exceeding the calyx. Legume linear, straight, flat, acuminate or apiculate, stipitate, valves coriaceous, glabrous, obscurely transversely veined, 5–8-seeded, 2 1/2–4 in. long, 1/3– 2/3 in. broad.