Euphorbia keithii, the Swazi Euphorbia, is a shrub or small tree found in the eastern parts of Swaziland. It grows to about 7 m in a habitat of rocky mountainsides. The branches tend to spread from the base with the upper parts of every stem being erect and displaying irregular constrictions up the stems, creating the segmented effect. The stems are usually five-angled, but they may occasionally have from three to six angles. Small rudimentary leaves are seen only on young stem parts. The paired spines are thick, occurring on the hard edge ridges.

The inflorescence of Euphorbia keithii is small and greenish yellow with two or three cyathia per cyme. The cyathia are false flowers called pseudanthia. These pseudanthia consist of bracts, nectar glands and an ovary and pistil where it is a female flower. Male flowers may often only consist of an anther on a stalk. A cyathium may be male, female or bisexual on the same plant.  This is how they grow on many Euphorbia species.  The fruit is a three-lobed greenish red capsule on a curved stalk that appears from midsummer onwards (Coates Palgrave, 2002 and Wikipedia).