Huernia loeseneriana expanding on rock

This Huernia loeseneriana plant has added to its occupied domain in Mpumalanga extensively over the years, in accordance with what the fractured sheetrock allowed. Maybe the grass also had a say in the limits to the succulent's growth, but fire impacts harder on dry winter grass than on thick succulent stems tending to hold their own on sheetrock.  

The succulent’s expansion can venture further than its usual competitors on this kind of rock. Sheetrock retains small pockets of dusty earth and humus, while providing drainage that prevents rot. Cold stress risk of the shallow-rooted succulent is reduced, contributing stability in the plant’s metabolism. The rock warms quickly in the morning, releasing heat slowly at night. 

The Highveld’s rocky grassland clearly suits this plant. The long-established human settlement in the distance seems to hold little threat (Germishuizen and Fabian, 1982; iNaturalist).