Psora is a genus of fungi in the Psoraceae family called fishscale lichens. They are lichenised fungi, (only) living on lichens and not the fungal part of the lichen itself.
The genus consists of about 30 species growing on soil and rock, mainly in arid areas, from the arctic to the subtropical regions of the world. Found in southern Africa, they also occur in the Americas, Europe, Asia and Australia. Psora decipiens, for instance, occurs on all continents apart from Antarctica. It has also been recorded in South Africa, near McGregor in the Western Cape.
This may be P. crenata that occurs at least in the Northern Cape, the Western Cape, the Eastern Cape and the Free State, seemingly the most common fishscale lichen in South Africa. The photo was taken in the south of Namaqualand during August.
There may also be a genus of flowering plants in the Asteraceae family called Psora (not South African), containing one species, Psora orientalis, an “unresolved name” (iNaturalist; iSpot; Wikipedia; www.theplantlist.org).