Prenia vanrensburgii, a perennial succulent, creeps over sand and rocks by the sea. The prostrate growth habit is shared by several of the other eight members of this genus, giving cause for the choice of the generic name, Prenia. This name comes from the Greek word prenes that means prostrate.

The plant forms attractive mats in the growth season when the leaves are lush. There is a waxy leaf covering that easily rubs off. The leaves are opposite. The stems are creamy yellow, contrasting with the leaves (Mustart, et al, 1997; Smith, et al, 1998).