Euphorbia heptagona stems are much branched. They often branch low down, but sometimes higher up as seen here. The two young stem-tip branches, adorned with fresh-looking spines, are still nearly globular.

Note the difference between the stem sections on them and the thick vertical ridges on the older stems lower down. The spines still carry some remains of past cyathia at their tips. Spines emerge from the gaps between the tubercle-like stem sections (Vlok and Schutte-Vlok, 2010).