Euphorbia pulvinata

Euphorbia pulvinata, commonly the prickly-leaved cushion euphorbia or prickly heaps, in Afrikaans voetangel (foot sting) as some other spiny euphorbias are also known and in Zulu inkamamasane,  is a mound-forming stem succulent reaching 15 cm to 35 cm in height and 1,5 m in diameter. 

The spectacular visible component of the plant is the geometrically regular, dome-shaped structure in picture, consisting of numerous stout, similarly shaped branches. In the growing plant the mound broadens gradually over many years as more branches are added. These finger-like branches emerge from a broad caudiciform base, the attenuating taproot comprising the invisible component, unless one digs. Branch length changes imperceptibly among adjacent stems, delivering a smooth overall shape in concert. The dome-shape is retained as the central branches grow just so slightly taller above the peripheral ones, like slow-motion soldiers on parade, retaining the attractive regular mound shape as it increases in size. Every branch or stem has seven or eight acutely angled ridges, along the edges of which small, sharp spines occur.

Now who would say that one cannot find mathematical beauty and structural engineering genius in a succulent?

The species distribution is widespread in the east of South Africa, from the Eastern Cape, through KwaZulu-Natal and the Free State to Mpumalanga and Limpopo. It is also found in some neighbouring countries.

The habitat is rocky grassland, sometimes on sheetrock. The species is not considered threatened in habitat early in the twenty first century (Frandsen, 2017; Smith, et al, 2017; Pooley, 1998; iNaturalist; http://redlist.sanbi.org).