Shrub or tree 5–35 m. high, unarmed or (I.T.U., ed. 2: 223) often spinous on juvenile and sucker shoots; crown spreading. Young branchlets puberulous. Leaves: rhachides ± densely and shortly crisped-pubescent or puberulous; pinnae 5–7 pairs; leaflets 11–22(–25 fide I.T.U.) pairs, somewhat obliquely oblong, and widest near the base which is slightly auricled on both sides, 7–15 mm. long, 2.5–6 mm. wide, narrowed to a usually obtuse apex, glabrous on both surfaces except for ciliolate margins at base, with the lateral nerves rather close and fine; the basal pair of leaflets on each pinna is characteristically represented by a single leaflet only, on the lower side, that on the upper side being replaced by a minute stipel. Inflorescences on peduncles 1.2–4.5 cm. long. Flowers white, sessile or subsessile. Calyx 3–3.5 mm. long, glabrous or subglabrous except on teeth. Corolla 5–7 mm. long, glabrous outside. Pods about 10–28 cm. long, 1.3–2 cm. wide, ± regularly lobed along one or both sutures which are puberulous, the pod otherwise subglabrous or sparingly puberulous. Seeds ± flattened, brown, 6–9 mm. long, 6.5–7 mm. wide. Fig. 23.