Flowers white, in heads on axillary, tomentose or densely pubescent, eglandular peduncles 0.4–1.5 cm. long; involucel basal or in lower half of peduncle.
Leaves: rhachis 0.5–4.5 cm. long, pubescent or tomentose; pinnae (3–)4–10 pairs; leaflets 6–15(–20) pairs, 0.75–3.5 mm. long, 0.5–1.5 mm. wide, usually ciliate or pubescent.
Stipules spinescent, straight or nearly so, slightly ascending to slightly deflexed, on mature shoots (0.4–)1–3.5 cm. long (to 4.5 cm. on robust apparently juvenile shoots); “ant-galls” and other prickles absent.
Shrub 0.3–2 m. high, usually low, flat-topped and up to 2.4–4.5 m. wide, branching from base or sometimes with a very short main stem exposed.
Young branchlets puberulous to pubescent or sometimes tomentose (hairs, to 0.5 mm. long), usually glabrescent, grey to grey-brown, sometimes purplish-brown or dark grey; epidermis not or inconspicuously peeling or flaking; lenticels inconspicuous, or pale and dot-like.
Seeds large, blackish, minutely roughened or smooth, ellipsoid to subglobose, 9–13 mm. in diameter; central areole 7–10 mm. long, 3–4.5 mm. wide.
Corolla 2.5–3 mm. long; lobes densely white-pubescent outside.
Pods (Fig. 17/62, A & B, p. 68) falcate to straight or nearly so, thick and woody, ultimately dehiscent, 7–13(–15) cm. long, 1.3–2.5 cm. wide, densely velvety-pubescent or tomentellous, brown to brownish-crimson, longitudinally veined, not winged.