Tree to 18 m high, branches usually spreading, crown typically flattened and spreading or umbrella-shaped, sometimes branches ascending and crown conical, particularly in young plants. Bark yellowish-or greyish-brown, rough, typically papery, the outer layers flaking off to expose a yellowish inner layer, sometimes ± smooth and not flaking; young branchlets yellowish-or greyish-brown, smooth or the outer bark flaking away to reveal a yellowish inner layer, glabrous to densely tomentose, indumentum golden to greyish-white. Stipules spinescent, in pairs, 0,3-7,8 cm long, straight or almost so, whitish, glabrous to densely tomentose; other prickles absent. Leaves glabrous to densely tomentose, indumentum golden to greyish-white: petiole 0,2-1 cm long, adaxial gland present, often just below the lowest pinna pair, yellowish to reddish-brown, up to 2 x 1,5 mm; rhachis 2,5-12,8 cm long, a small gland present at the junction of the top 1-6 pinnae pairs only, between each pair, or absent from some; pinnae (4)8-30 pairs; rhachillae 0,8-4(6,5) cm long; leafÂlets 13-45 pairs per pinna, 1,2-6,5 X 0,5-1,6 mm, linear to linear-oblong, apex rounded to acute, margins with or without cilia, usually glabrous beneath, midrib and sometimes a few lateral nerves often fairly prominent beneath. Inflorescences capitate, on axillary peduncles, solitary or fascicled. Flowers pale yellowish-white, sessile or very shortly pedicelled; peduncles 1,4-5,8 cm long, glabrous to densely tomentose, inÂdumentum golden to greyish-white, egland-ular; involucel apical or in the upper half of the peduncle. Calyx sparingly pubescent throughout or glabrous except for pubesÂcence towards the apices of the lobes, tube 1,6-2,4 mm long, lobes up to 0,8 mm long. Corolla glabrous throughout or apices of lobes sparingly pubescent, tube 2,4-3,6 mm long, lobes up to 2 mm long. Stamen-filaÂments free, up to 9 mm long; anthers with a deciduous apical gland. Ovary sessile, up to 2,1 mm long, glabrous. Pods pale to dark yellowish- or reddish-brown, 5-19,5 x 1,3-3,3 cm, straight or slightly curved but sometimes ± falcate, somewhat flattened or at times oval in cross-section, thick and almost woody in texture when dry, tardily dehiscent, often only dehiscing on the ground, smooth, glossy and glabrous or subglabrous to densely pubescent especially on margins and stipe, indumentum frequently golden. Seeds olive to grey-brown, 7-12 x 5-8 mm, elliptic to subcircular, slightly compressed, smooth; areole 5-9,5 x 4-6 mm.
