Euphorbia heptagona also a pincushion

When a form of Euphorbia heptagona was known as E. enopla, the common name of pincushion euphorbia was quite appropriate for the way the succulent stem-tips form a shallow dome-shape over their compact branchings. The name still fits some of these plants, but the species is now more inclusive of diversity in form. A big specimen such as seen here is quite an attractive succulent highlight in the Karoo veld.  No wonder the plant has become a popular gardening subject.

The branches are thick columns, green and ribbed. Long red spines, the stalks of the cyathia, emerge from the stem-top centre in vertical rows (i.e. columns) along the rib edges. The spines blacken, then dry as the spurge stems lengthen, leaving them further below the stem-tips, although much in the same positions. Relegated to the hard life of spine duty, young successors at the top replace them in the softer, more flamboyant occupations.

The male and female cyathia (flowers) appear on separate plants at the end of the peduncles in new growth at the stem-tips, resembling the ageing spikes on the plant (Euston-Brown and Kruger, 2017; Smith, et al, 2017; Vlok and Schutte-Vlok, 2015; Smith, et al, 1997; iNaturalist).