At last, some interesting information from spam:
Q: What is Hoodia?
A: A type of cactus. Hoodia Gordonii is a succulent in the family Asclepiadaceae. It forms multi-stemmed clumps 45cm (18in) high and bears unpleasant-smelling, pale purple disc-shaped flowers 7.5-10cm (3-4in) in diameter. Hoodia Gordonii grows in semi-arid areas of South Africa. The San people, formerly known as bushmen, of the Kalahari eat the bitter-tasting plant on long hunting expeditions.