Euphorbia tetragona stems

The honey euphorbia, as Euphorbia tetragona is known locally, is a source of honey, although not a very palatable kind for humans. Bees thrive on Euphorbia pollen of many species in many places. In some cases they benefit from the fact that their honey causes a burning sensation in people’s throats, leaving more of it for their own consumption.

Although the name says four-angled (tetragona), some of the branchlets of this tree actually have five angles, stem ridges or wings; sometimes possibly more. The edges are slightly tubercled, the flat parts inbetween smooth and green. The stems have slight, irregularly spaced constrictions indicating seasonal growth changes. The main stems, as well as sometimes a few big stems low down, gradually lose their capacity to photosynthesise lower down, becoming whitish grey as can be seen here.

The inflorescence is greenish yellow with cyathia positioned in many horizontal rows of three on the ridges near stem tops. The central cyathium is male, the laterals bisexual. Next to every cyathium stalk two bracts are present. 

The fruit capsule is nearly globose and three-lobed, about 9 mm in diameter (Frandsen, 2017; Smith, et al, 2017; Coates Palgrave, 2002; iNaturalist).