Euphorbia avasmontana

Euphorbia avasmontana, previously E. avasmontana var. avasmontana is a robust stem succulent that grows a multitude of erect stems, branching at the base. The plant is very spiny, not easy to handle. The toxic white latex should not be ingested or come into contact with the eyes. Plant height is about 2 m.

The columnar, erect stems grow bunched closely together. Suckering is common, the branching plant may exceed 2 m in width. The stems are about 7 cm in diameter, rarely rebranching higher up. The yellow-green stems show slight constrictions at irregular intervals. Stems are typically five-angled, the protruding vertical ridges common to many Euphorbia species rarely as many as seven.

The new growth leaves at stem-tips are small and ephemeral, dropping off very soon. Photosynthesis is mainly a function of the stems. The rigid, straight stipular spines grow in angled pairs on the hard, dark red stem ridges that age to pale grey. Identification of the species is made simpler by the three horizontally positioned cyathia scars, appearing regularly on the ridge between the spine pairs near stem tops.

Yellow flowers or false flowers appear in short cymes, the similar stem-tip inflorescences on the ridges, spaced by the smooth vertical channels. The plant flowers in spring to autumn, sometimes a little in winter as well.

The fruits are three-angled capsules, 6 mm in diameter. The seeds are smooth and globose, less than 2 mm in diameter.

The species distribution is near the Gariep River, from Prieska to the Richtersveld and in southern Namibia.

The habitat is arid succulent Karoo, Nama Karoo and rocky desert slopes. The species is not considered threatened in habitat early in the twenty first century (Frandsen, 2017; Smith, et al, 2017; Van Jaarsveld, et al, 2006; iNaturalist; www.cactus-art.biz; http://redlist.sanbi.org).