Tavaresia Welwitsch
Named for José Tavares de Macedo, a Portuguese botanist, circa 1850, and distributed through Angola, Botswana, Namibia, Zimbabwe and South Africa, the plant stems have persistent spines which although much more slender resemble Hoodia. The flower characteristics however much more resemble Huernia although the flowers are much larger than those found in that genus. The species shown here is Tavaresia barklyi but sadly with no locality data. The plant 'Red leopard' shown is a hybrid with Orbea variegata which is a cultivar and is not found as a natural hybrid in nature despite the partial overlap in the distribution range of the species.
Tridentea Haworth
From the Latin 'tri-'; three, and 'dentis'; teeth, for the 3-toothed interstaminal segments of the corona, the genus is found in Namibia , Botswana, and South Africa. Peter Bruyns postulates a close affinity to Hoodia and Lavrania concerning flower structure, whilst stem morphology more favours the genus Orbea.
Tridentea gemmiflora
According to the literature, found only in South Africa in the Mpumalanga, Free State, Eastern and Northern Cape Provinces, however I collected a stem of the plant shown on the Ghamka Road, 10k SE of Calitzdorp, in the Western Cape Province in 2000.
This smaller flowered species from Namibia, the Free State and Northern and Western Cape Provinces is closely related to Tridentea dwequensis.
Found in southern Namibia, the Richtersveld area, of the Northern Cape Province and the North-West Province of South Africa this species is very closely related to T. gemmiflora.