Curio is a genus of leaf-succulents forming part of the Asteraceae or daisy family and the Asteroideae subfamily. There are stemless Curio species, some erect and others growing prostrate.
The generic name is derived from the Latin word curiosus meaning curious, maybe referring to a feature of plant shape. What is commonplace to some may be curious to others; familiarity takes time.
The leaves are roughly cylindrical, sometimes curving. Some species have “windows” in the succulent leaves, allowing sunlight to enter for photosynthesis in cells against the inside walls.
The plants bear discoid flowerheads. It seems as if most species lack ray florets. The outer ring of florets in the discs are then usually female, the central ones bisexual.
Up to 1997 all the Curio species formed part of the Senecio genus, some of them still earlier in Kleinia. Such changes reflect increased understanding of relationships among and evolution of different plants, in recent times the knowledge greatly enhanced by phylogenetic studies involving DNA.
There are about 20 Curio species of which 14 in South Africa, some with recognised varieties.
This photo shows a plant that has been through the drought wars of attrition near Calitzdorp. The leaf surfaces bear longitudinal vein lines and are covered in a whitish bloom; that is where they are not discoloured by black lichen. There are tiny, brown mucros at the leaf-tips. The sunken channels on the still succulent, curved and erect leaves might fill out after the next rain. A guess that this may be Curio acaulis remains only that (Vlok and Schutte-Vlok, 2015; Wikipedia; http://pza.sanbi.org; http://redlist.sanbi.org).