Curio crassulaefolius used to be one of more than 1000 Senecio species in the world. Some of them have now been moved to Curio. This genus was created in 1997 by P.V. Heath for Senecio species that have elongated, succulent leaves and discoid flower heads.
The name is derived from the Latin word curiosus meaning curious, maybe a feature of plant shape. The most commonplace to some may be curious to others. Will the name change again when everybody concerned is familiar with these plants?
There is also an issue with the spelling of the specific epithet: some records have it as crassulifolius, apparently the same plant. Both names indicate leaf resemblance with Crassula. Maybe one will encounter a Crassula with such leaves one day. Time brings either progress or a return to chaos; we'll see, those of us who may be still around.
The picture was taken at Kirstenbosch. The species name was found in the Bartholomeusklip Plant List (a reserve to the north of Wellington in the Boland), although no clear indication could be determined of the species distribution.
The leaves are fleshy, cylindrical and spindle-shaped, pointing upwards and inwards in attractive rosette-like clusters around the tops of the branched stems. Leaf colour is blue-green or green to yellow-green when older. The flowers are yellow and occur in clusters above the leaves (Wikipedia; www.redlist.sanbi.org).