Shrub, often with many stems, or a tree to 10 m high; trunk to 0,3 diam.; crown often flattened and spreading somewhat. Bark pale to dark yellowish- or greyish-brown, rough, the outer layer papery and flaking or peeling off; young branchlets yellowish- or greyish-brown to purplish, puberulous to pubescent, sometimes glabrous, indumentum usually slightly golden. Stipules not spinescent, in pairs, linear, 2-4,2 X 0,2-0,8 mm, soon deciduous. Prickles in pairs below the nodes (very rarely in threes but then all three prickles point downward), usually strongly recurved, broad-based, grey-brown to blackish, up to 7 mm long. Leaves: petiole (0,7)1,3-2,5(4) cm long, adaxial gland present or absent, variable in position, often slightly raised, 0,3-0,7(1) X 0,1-0,5 mm; rhachis (1)1,5-2,7(5) cm long, usually puberulous to densely pubescent, glands variable, either at the junction of some of the pinnae pairs, between the top pair only or sometimes absent; pinnae 3-7 pairs; rhachil-lae (1)1,2-3(3,9) cm long, usually puberulous to densely pubescent; leaflets 10-27 pairs per pinna, 3-7,5(10) X (0,75)1-1,6(2,8) mm, obliquely oblong, often slightly falcate or the upper somewhat obovate, apex usually oblique, acute or subacute, sometimes ± rounded, veins often prominent beneath at first but becoming obscure with age, glabrous below or occasionally sparingly pubescent, margins with or without cilia. Inflorescences spicate, fascicled or crowded into an irregular terminal panicle, sometimes solitary. Flowers yellowish-white, sessile; spikes (1,8)2,2-4,5(6) cm long, peduncles (0,6)1,2-2,5 cm long, pubescent. Calyx campanulate, puberu­lous to densely pubescent, tube 1-2,2 mm long, lobes 0,6-1,8 mm long. Corolla tubular, appressed-pubescent, especially towards apices of lobes.tube up to 3 mm long, lobes up to 1,5 mm long. Stamen-filaments free, up to 8 mm long ;anthers 0,2-0,25 mm across, with a deci­duous apical gland. Ovary 0,5-1,9 mm long, glabrous, sessile or shortly stipitate. Pods fawn to dark brown, 3-13 X 1,1-1,8(2,3) cm, linear-oblong, straight, rounded to acute or acuminate apically, longitudinally dehis­cent, venose, coriaceous, subglabrous except for pubescence on the margins and stipe, glands absent or few and inconspicuous. Seeds olive-brown, usually subcircular, 7-11 X 7-11 mm, compressed; areole 1-3 X 2-4,5 mm, horse-shoe shaped.