Euphorbia atrispina, the swartdoringnoors in Afrikaans, is a small plant (20 cm) with many branches at ground level or higher up from the strong central root. Young plants may look like little trees or spreading shrubs. As the undisturbed plant matures it assumes a mounded cushion shape with a large number of stem tips visible on the dome-like surface.
The squat columnar stems have about seven to nine ridges where sharp long spines persist for some time. The spines are purplish red to black when young. The flowers are small and yellow, appearing in spring at the tips of the new spines on the stem tops. The fruits are globose and purple in colour.
The plant is said to grow in the Little Karoo between Ladismith and Oudtshoorn, as well as on rocky slopes towards the coast. It is unknown which of the two recorded varieties, E. atrispina var. atrispina or var. viridis, the one in the photograph is (Van Jaarsveld, et al, 2000; Bond and Goldblatt, 1984; www.learn2grow.com).