Hoodia are into the family (or subfamily) Asclepiadaceae. The family Asclepiadaceae is now, according to AGP, included in the Apocynaceae (Endress & Bruyns, 2000).
The AGP, Angiosperm Phylogeny Group is an international group of systematic botanists.
Now there are five subfamilies into Apocynaceae:
- Rauvolfioideae (originally into Apocynaceae)
- Apocynoideae (originally into Apocynaceae)
- Periplocoideae (originally intoAsclepiadaceae)
- Secamonoideae (originally into Asclepiadaceae)
- Asclepiadoideae (originally into Asclepiadaceae)
Into the Asclepiadeaceae we have the tribe Stapeliae (all succulents and leafless) with the following list of genera included:
Angolluma, Caralluma, Desmidorchis, Duvalia, Echidnopsis, Edithcolea, Hoodia, Huernia, Huerniopsis, Larryleachia, Notechidnopsis, Orbea, Orbeopsis, Piaranthus, Pachycymbium, Pectinaria, Pseudolithos, Pseudopectinaria, Quaqua, Rhytidocaulon, Stapelia, Stapelianthus, Stapeliopsis, Tavaresia, Tridentea, Tromotriche, and Whitesloanea.
So Hoodia is a genus into the tribu Stapeliae, into the subfamily (but most ot time refered as family) Asclepiadaceae, into the family Apocynaceae.
The genus is named for a Mr. Hood who was a succulent plant grower in England in 1830’and named the hoodia plant.
Hoodia Plants Scientific Classification:
Trichocaulon: You can find some Hoodias under this name. According to The British Cactus and Succulent Society Handbook of Shows (1991): Hoodia, Pseudolithos and Trichocaulon were all members of the Trichocaulon subgroup, and Trichocaulon a genus it is own, into Stapeliae.
Now Trichocaulon genus is not longer accepted and was split in two.
Some Trichocaulons had stems with spiny tubercles, others had stems with rounded tubercles. The spiny ones are now into Hoodia, and the rounded ones got two separate generic names from two taxonomists. So the plants (old Trichocaulons with rounded tubercles) are now either called Lavrania (after John Lavranos), or Larryleachia (after Larry Leach). The final decision isn't in yet: Lavrania was winning, but recently Larryleachia is recovering strong.