Hoodia - Sweet (1830) ex Decaisne (1844)
The genus Hoodia includes around 18 species of clumping spiny stem succulents from arid parts of South Africa, Namibia and Angola. Some species have been separated from the genus Trichocaulon in which they were formerly included. Despite their cactiform appearance, these plants are not cacti as often stated. The erect green stems, up to 3ft tall in some species, carry many tubercles that merge into ribs. Each tubercle bears a single whiteish spine. The large disk-shaped flowers typical of this genus in red, purple or flesh colours are attractive at a distance, but produce an unpleasantly strong odour of decaying carrion to attract the flies that pollinate them. Species formerly in Trichocaulon have smaller 5-lobed flowers.
named for: Van Hood, 19th C. English succulent plant grower
Hoodia gordonii was discovered by Col. Gordon (1778), named as Stapelia gordonii by Masson and transferred to the genus Hoodia by Sweet (1830). Hoodia gordonii is of interest as a source of an appetite-suppressing chemical (steroidal-glycoside). Pieces of the bitter stem are eaten by bushmen to suppress their appetite and thirst. The safety and long-term effects of eating Hoodia remain unknown.
Cultivation is challenging as Hoodias are intolerant of excess water, humidity and low winter temperatures and easily destroyed by moulds. Species coming from winter rainfall areas may grow during the Northern-hemisphere winter if kept warm or may collapse. A plant that has grown happily for several years can turn into a mush for no apparent reason.
In a dry tropical climate, Hoodias can be grown outside and perhaps this is where they are best suited.