Tree 20-30(-41) m high. Stipules connate in the lower half or almost entirely when very young, up to 10 mm long, puberulous on both surfaces, caducous. Leaves (5-or) 6-8-jugate; petiole 1.5-3.5 cm and rachis 11-22 cm long, pubescent, glabrescent. Leaflets coriaceous, elliptic, elliptic-oblong, lanceolate, rarely elliptic-obovate, 3.9-8.7 (-16) by 1.5-2.6(-5) cm, lower ones usually smaller than the upper ones; apex acuminate; base obtuse, rounded, often symmetric; upper surface glossy and almost glabrous; lower surfaces glossy, glabrous except pubescent on the midrib; petiolules very short, up to c. 5 mm, sparsely pubescent. Inflorescences paniculate, up to 20(-26) cm long, lateral branches up to c. 4.5 cm long, both rachis and branches densely puberulous; bracts triangular, 3-4 mm long, densely puberulous; bracteoles minute, lanceolate, less than 1 mm long, puberulous on both surfaces; pedicels 3-5 mm, densely puberulous. Calyx lobes broadly lanceolate or ovate, 3.5-6 by c. 3 mm, unarmed, densely puberulous outside, densely appressed hairy inside. Petal oblong-elliptic, 7-8.5 by 2-2.5 mm, fleshy; outside densely puberulous in the lateral parts of lower half; inside glabrous; margin villose. Stamens: filaments with basal parts connate c. 1 mm high, free filaments and staminodes up to c. 12 mm, sparsely hairy on the lower parts; anthers 2 (perfect) largest, ellipsoid, c. 3 mm long, the others smaller, c. 2 mm long. Ovary subsessile or very shortly stipitate, subrhomboid, c. 3 mm long, densely woolly along the suture, glabrous in the centre, with some minute protuberances observed under the dissecting microscope, 5-7-ovuled; style up to c. 12 mm, recurvate, glabrous or thinly puberulous in the basal part; stigma obscure. Pods on a stout peduncle up to 1.7 cm long, ellipsoid, oblong-or broad-ellipsoid, or broadly ovoid, 7.5-15 by 5.5-7 cm, flattened, hard, covered with some scattered, slender, sharp spines (up to c. 3 mm), beak recurvate, c. 10 mm long, 1-3-seeded. Seeds suborbicular or broadly ovoid, 1.5-2.3 by 1.5-2 cm, smooth, on top of a larger aril; aril very variable in shape and size, smooth or slightly irregular on the surface, slightly reniform, 2.5-2.8 by 1.5-1.8 cm.
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