Euphorbia heptagona

Euphorbia heptagona, the klipnoors (stone euphorbia) or donkienoors (donkey euphorbia) and previously scientifically E. atrispina, grows many stems branched at the base or higher up. The stem succulent reaches 1 m in height when conditions permit, often only 30 cm in its habitat that ranges across several levels of harshness. Tiny leaves are seen for a short while on new growth at stem tips only.

The stem succulent earned the specific name of heptagona from the fact that the most common number of stem ridges is seven, ranging mostly from six to eight. The specific name is derived from the Greek words hepta meaning seven and gonia meaning angle, referring to the number of stem ridges. The species now includes the earlier E. enopla or boknoors (goat or antelope euphorbia or spurge), E. atrispina or swartdoringnoors (black thorn spurge) and some varieties of those.

The species distribution is in the Western Cape from Touws River and Montagu across parts of the Karoo and the Little Karoo to Jansenville in the Eastern Cape. This plant was seen in the Rooiberg south of Calitzdorp near the end of May.

The habitat is rocky north-facing slopes and outcrops among dry karoid scrub and thicket in various soils types. The habitat population is deemed of least concern early in the twenty first century (Euston-Brown and Kruger, 2023; Smith, et al, 2017; Vlok and Schutte-Vlok, 2015; iNaturalist; iSpot; http://redlist.sanbi.org).