Carissa shrubs, trees or scramblers are popular among gardeners. They perform well in cultivation. The flower in picture has corolla lobes that overlap to the left or anticlockwise. The margins curve in on the curving, oblong lobes with rounded tips. A tiny protrusion or mucro is visible on lobe tips.
Children, birds and some animals eat the fruit, the round or oblong, fleshy berries. The fruit of some species, like C. haematocarpa, will stain teeth blue or black when eaten. One such animal is the black rhinoceros. Jellies and jams are made, or used to be made of the fruits.
Several of these plants are commonly called num-num. They have spines that fork in characteristic manner in some of the species and are often stout. The leathery leaves are opposite, ovate in shape with entire margins. The genus forms part of the Apocynaceae family and contain milky latex as is common in this, the milkweed family. Five of the twenty species grow in southern Africa (Coates Palgrave, 2002; Van Wyk and Van Wyk, 1997).