Shrub, sometimes scrambling. Stems and branches armed with short, broad, slightly curved thorns. Leaves sensitive, twice compound with 6-14 pairs of pinnae with a slender spine on the rhachis between each pair. Flowers in subspherical heads, c. 1 cm in diameter, in the upper leaf axils, mauve or pink. Pods in clusters, covered in golden-brown, bristly hairs.