Stout, long-lived shrubs up to 3 m tall with upright or arching branches. Occasionally, some branches have the characteristic of lianas and, if they can be supported by something, grow up to 10 m high. The root system has a main taproot which is usually supplemented by shallowly rooting underground spurs. The branches and twigs are green and usually covered with irregularly spaced, thick, uniformly shaped, hook-shaped spines with an enlarged base.