A woody shrub usually growing 0.5-2.5 m tall with spiny stems. The 'leaves' are usually reduced to narrow, rigid, dark-green spines (5-35 mm long and about 1.5 mm wide) that are borne in clusters along the branches. It produces masses of bright yellow pea-shaped flowers (15-25 mm long). These flowers are borne in the leaf forks or in small clusters at the tips of the branches. Its small egg-shaped or oblong pods (10-25 mm long and 6-8 mm wide) turn dark brown or black in colour as they mature and are densely covered in long spreading hairs.