Euphorbia triangularis leaves

The spine pairs of Euphorbia triangularis are separated by a wide angle, diverging from the basal cushion. They are usually straight, but not quite all of them, as can be seen. The spines are sturdy and can do damage; young ones initially softer and yellowish brown. As the spines dry out they turn grey. They grow spaced on the wing-like, angled spine ridges or margins, the spaces between becoming from 4 cm to 9 cm wide.

The stems may taper or otherwise change in thickness variously from base to tip, accentuated by an abruptness at the periodic constrictions.

The yellowish leaves are ovate, folded along the midrib and sessile. They are short-lived, soon to drop off. This photo was taken in midsummer (JSTOR; Coates Palgrave, 2002; www.witbos.co.za).