Euphorbia zoutpansbergensis

Euphorbia zoutpansbergensis, commonly the Soutpansberg naboom, is a robust shrub or small tree, a spiny stem succulent that reaches 5 m in height (SA Tree List No. 357). 

The tree grows multi-stemmed, ending in numerous green upper branchlets. The branchlet tips form a candelabra shape. Every branchlet has five to seven ribs or spiny ridges, mostly six. Lower branches may hang down, although the majority curve up. The segments are from 2 cm to 3,5 cm wide, constricted into segments from 5 cm to 10 cm long.

The paired spines are thin, sharp and diverging sideways at evenly spaced intervals up the ridges. They are reddish when young, grey, dry and persistent when old. The spines are sometimes comparatively far apart on well growing plants in cultivation and the spine ridges are continuous in older plants, not yet on young stems. Spines become up to 1 cm long.

The cyathia (false flowers or pseudanthia) on the stem tops in season (spring) are light yellow, small and rounded, growing solitary or in cymes of up to three. The fruit is three-lobed and green, about 10 mm in diameter. It is borne on a longish stalk of up to 6 mm.

The distribution of this South African endemic is comparatively small in Limpopo, on the northern slopes of the Soutpansberg Mountains and the Blouberg. 

The habitat is grassland and bushveld on rocky slopes, cliffs and sheltered ravines in quartzite soils at elevations from 1100 m to 1500 m. The species is considered of least concern in habitat early in the twenty first century as its remoteness and inaccessibility largely thwarts plant collectors.

This is an improved rating of the species population in nature. Every plant or animal moving up the scale towards extinction is a concern, as the survival of all species is dependent upon maintaining diversity of species (Frandsen, 2017; Smith, et al, 2017; Coates Palgrave, 2002; www.euphorbia.de; http://redlist.sanbi.org).