Hoodia
Hoodia is a genus of clump-forming, spiny, many-ribbed stem succulents in the milkweed family Apocynaceae, native to the arid and semi-arid country of southern Africa. Like their relatives the stapeliads, hoodias produce fleshy, leafless stems and striking wheel-shaped "carrion flowers" pollinated by flies. Several species — most famously Hoodia gordonii — are traditionally chewed by San (Bushman) peoples and have been widely marketed as appetite suppressants, which combined with wild collection has led to CITES protection for the genus.
Description
Hoodias are leafless succulents that build up dense clumps of erect, cylindrical stems, typically anywhere from a hand-span to knee-high depending on the species and its age. Each stem is divided into numerous low vertical ribs (often many more than the ribs of a true cactus), and along the edges of these ribs sit rows of hardened, spine-tipped tubercles. Despite the fierce look, these are not cactus spines but modified tubercle points — a case of convergent evolution with the Cactaceae, which hoodias are not related to.
The flowers are the real spectacle. Borne near the stem tips, they are usually shallow saucers or broad discs, ranging from pale straw and tan to deep flesh-pink and maroon, and in many species they carry the faint-to-strong smell of carrion that draws in the flies that pollinate them. As stapeliads, hoodias share the family's intricate flower structure, and after pollination they form paired, horn-like follicles packed with tufted, wind-borne seed.
Distribution and habitat
The genus is centred on the dry western half of southern Africa, with species spread across Namibia, South Africa (notably the Northern Cape and Karoo), Botswana and into Angola. Plants grow in genuinely harsh, low-rainfall country — stony flats, rocky slopes and desert scrub — often sheltering at the base of nurse shrubs that give young plants a little shade and protection from grazers. They are adapted to long dry spells and cool, sunny winters in much of their range.
Notable species
- Hoodia gordonii — the best-known species, tall grey-green stems and large flesh-coloured flowers; the plant behind the "appetite suppressant" trade.
- Hoodia pilifera — a South African species with smaller, dark reddish, sometimes hairy-margined flowers.
- Hoodia currorii — a robust species from Namibia and Angola with showy tan-to-reddish blooms.
- Hoodia flava — noted for its yellowish flowers, from the arid interior of southern Africa.
Species boundaries in Hoodia are not always tidy, and plants hybridise readily where ranges overlap, so garden and nursery material is sometimes of uncertain parentage.
Cultivation
Hoodias have a reputation for being fussy, and they are among the more challenging stapeliads to keep long-term — but understanding where they come from goes a long way. The overriding rule is drainage and restraint with water. Grow them in a very open, gritty, mostly mineral mix in a pot no larger than needed, and give them the brightest position you can: strong light keeps stems firm and compact, while too little light produces soft, etiolated growth prone to collapse.
Water only when the mix has dried right out and the plant is in active growth, easing off sharply as temperatures fall; keep them nearly dry and frost-free through winter. Warmth suits them — they resent cold, damp conditions, which invite the rot that is the usual cause of death. Because hoodias are notoriously hard to root and prone to root loss, many growers find them easier and more reliable when grafted onto a tougher, closely related rootstock such as a vigorous Ceropegia, which sidesteps their touchy root systems. See Watering, Repotting and Pests and diseases for general technique; mealybugs and stem rot are the main things to watch for.
Propagation
Fresh seed is the most rewarding route and germinates readily on a warm, gritty surface, though seedlings are slow and demand the same careful, dry-leaning regime as adults. Cuttings can be taken but are notoriously reluctant to root and prone to rotting at the base — let any cutting callus thoroughly before setting it barely into dry, sharp mix. See Propagation — seed and Propagation — cuttings.
Hobby and conservation notes
Hoodia occupies an unusual place in the hobby: it is prized by stapeliad and caudiciform specialists as a collector's challenge, yet it is also caught up in a much larger commercial story. Following interest in its traditional use by San peoples as a hunger and thirst suppressant, H. gordonii in particular was heavily promoted in the dietary-supplement trade, driving wild harvesting and prompting conservation concern. The whole genus is now listed under CITES Appendix II, which regulates international trade in wild-collected material.
For hobbyists the practical takeaways are simple: buy nursery-propagated plants, keep records of any wild-origin claims with a healthy scepticism, and value hoodias as horticultural subjects rather than commodities. This wiki covers Hoodia purely as a group of succulents to grow and enjoy; it offers no medicinal or consumption guidance of any kind.
See also
- Hoodia gordonii · Hoodia pilifera · Hoodia currorii
- Stapelia and other stapeliads · Apocynaceae
- Grafting · Soil and potting mix · Watering · Propagation — seed · Propagation — cuttings · Pests and diseases