Carissa bispinosa, the common num-num, is a spiny evergreen shrub, sometimes a scrambler, occasionally a small tree of up to 5 m in height, commonly less than half that (SA Tree List, 640.1).
The bark on the much-branched stems is initially green, becoming partly grey and wrinkled. Forked spines are conspicuous upon the stems. The plant exudes a milky latex when the skin is damaged. This is a heterogeneous species of varied appearance.
The photo was taken near the Seweweekspoort where C. bispinosa as well as C. haematocarpa might be expected, but since the sinking of C. haematocarpa into C. spinosa, the problem of distinguishing between the two could be considered as something of the past. Appearance differences may, however, cause the two names to last beside each other for some time, although not officially.
The species distribution is widespread through the southern, eastern and north-eastern parts of South Africa, as well as in several African countries. The habitat includes dry woodland, forest, bushveld and coastal scrub. In the east of the country, particularly parts of the eastern Cape and KwaZulu-Natal the plant is found in forest margins and the under-storey of evergreen forests. The species is not considered to be threatened across its varied habitats early in the twenty first century (Coates Palgrave, 2002; Van Wyk and Van Wyk, 1997; Pooley, 1993; www.redlist.sanbi.org).