MARIENTAL, Namibia // When fully grown, the plant resembles something from The Day of the Triffids or some other science-fiction creation: a squat succulent with thick, spiky arms, purple fleshy petals and seedpods like rhino horns.

Hoodia gordonii is no beauty, but this humble plant is Africa's latest cash crop, priced almost like a narcotic at $40 an ounce. The plant, which grows wild in the Kalahari Desert of southern Africa, was once used by indigenous tribes to suppress hunger and thirst when hunting. Now it's such a darling of the international dieting industry that doing an Internet search on the plant's name returns about 14 million responses.

The resulting demand is so hot, wild supplies have been severely compromised, smuggling is rife and farmers in southern Africa are trying to get in on the game.

"You start doing the sums; it's too good to be true. You want to throw your calculator away. It's an impossible phenomenon," said hoodia farmer Dougal Bassingthwaighte.

With international giant Unilever licensed to commercialize hoodia and international demand far outstripping supply, there's a mad race on to get plants to the market.

Bassingthwaighte, 65, who is farming hoodia with his son, Kirk, has 130,000 seedlings from his nursery, where they begin as tiny green sprouts, being planted in his fields. In about two years, when he plans to harvest them, each is likely to weigh about 4 pounds. He hopes to have a million plants next year.

But the explosion of interest has not only put enormous pressure on the rare plant – listed as an endangered species by international treaty – it also puts intense pressure on an embryonic market that could be a boon for Africans if it could grow at a natural and sustainable pace.

Sadly, the craze for hoodia brings out the worst in people. Tiny as it is, the industry is rife with fierce competitive secrecy, quack products and illegal harvesting. Next, authorities in South Africa fear, comes the inevitable interest of organized gangsters.

Whether hoodia works as a diet aid has not been scientifically proven. Pills and capsules claiming to contain hoodia are widely available in the United States online and at stores that sell herbal supplements. Such products are largely exempt from U.S. government regulations, which require drugs to be tested for safety and effectiveness before being sold.