Tree 10–15 m. high, with openly branched flat crown and rough or smooth dark grey or grey-green bark. Young branchlets puberulous or very shortly pubescent with short curved hairs that are yellowish, at least when dry. Stipules not spinescent. Prickles in pairs just below nodes, deep grey to blackish, spreading or pointing a little upwards, usually straight or only slightly curved (see, however, note below), up to 4–6 mm. long. Leaves: petiole with a small gland 0.4–0.7 mm. in diameter; rhachis puberulous, glandular between the top 1–4 pairs of pinnae; pinnae 6–9 pairs; leaflets (9–)13–31 pairs, 4–8 mm. long, 1.5–2(–3.5) mm. wide, oblong, oblique at base and the subacute to obtuse apex, pale glaucescent beneath, puberulous especially beneath, lateral nerves visible when young, becoming obscure. Flowers sessile or nearly so, in spikes 6–10 cm. long on 1.5–3 cm. long peduncles, produced with the leaves; axis puberulous. Calyx 1.5–2 mm. long, puberulous. Corolla 2–3 mm. long, glabrous or slightly puberulous on lobes outside, 5-lobed, exceeding the calyx. Stamen-filaments 4–5 mm. long, free; anthers 0.1 mm. across, with a caducous gland. Ovary glabrous, very shortly stipitate. Pods (Fig. 14/15, p. 52) probably not dehiscent, apparently irregularly breaking up, glabrous, oblong, straight, and smooth or nearly so, dark brown when dry, green when living, rather thick and turgid, rounded or acute at apex, 7–15 cm. long, 1.7–2.5 cm. wide. Seeds oblong-elliptic-lenticular, 10–13 mm. long, 7–9 mm. wide, hard-walled; central areole large, 7–9 × 4.5–5 mm., not impressed.
