Euphorbia triangularis (SA Tree List No. 356), the river euphorbia, is a candelabra-shaped tree that grows to 18 m tall. It is found in arid places as well as on river banks. The trunk is round with slight indications of angularity. The main branches all develop separate rounded crowns of younger branchlets.
The branches are three-angled as the name indicates, but occasionally four- or five-angled branchlets are also found. Young branchlets are yellow-green with slightly wavy or curved edges. A sometimes continuous horny rim has spaced groups of slender, yet vicious divergent spines; on other specimens the spine cluster cushions are discrete.
The periodic constrictions between stem sections may be more or less pronounced, possibly related to weather conditions in times when the stems were formed (Coates Palgrave, 2002; www.kumbulanursery.co.za).