Shrub 1-3 m. high, sometimes sprawling and forming thickets; young branchlets slender, glabrous, purplish. Stipules not spinescent, subulate-triangular. Prickles mostly scattered and single along the stems, rather small, to c. 6 mm. long, slightly arcuate-recurved; occasionally a few prickles tending to be grouped irregularly in pairs near the nodes. Leaves: rhachis 0·5-4·5 cm. long, unarmed or sometimes armed; gland on petiole often absent, sometimes a small gland towards the apex; glands also between the top 1-4 pairs of pinnae; pinnae 2-10 pairs, short, up to 1·9 cm. long; leaflets 14-32 pairs, imbricate, 1-3 x 0·5-0·7(1) mm., glabrous, rounded to subacute at the apex; midrib and lateral nerves obscure or only slightly prominent. Flowers white to yellow, sessile, in spikes 1·5-4 cm. long on peduncles (0·7)1·5-2·5(3) cm. long; axis glandular, otherwise glabrous or almost so. Calyx 1·5-2·25 mm. long, glabrous. Corolla 2·5-3 mm. long, glabrous. Stamen-filaments 5-6 mm. long; anthers 0·15-0·2 mm. across, with a caducous gland. Ovary glabrous, shortly stipitate. Pods brown or purplish, dehiscent, 3-6·5 (excluding stipe) x 1-1·6 cm., glabrous except for a few small glands (and occasionally some puberulence) towards the base, oblong to linear-oblong, straight, rounded to acuminate at the apex, attenuate at the base into a slender stipe 0·5-1·5 cm. long; margins usually ± irregularly sinuate or constricted. Seeds 5-8 mm. in diam., flattened; central areole small, 1·5-2 x 0·75-1·25 mm.
