WITDRAAI, South Africa -- The slight, wizened man kneels in the sand and speaks of the long desert hunting treks of his youth, where his grandfather gave him the fleshy pulp of the hoodia cactus plant to stave off hunger and thirst.
"The bushmen are always in the bush, so we know a lot," said David Kruipeir, 67, a traditional healer for the nomadic African people known as the San.
But the San have been wary of sharing their knowledge since their legal battle with the U.S. pharmaceutical giant Pfizer and a South African lab over plans to turn the hoodia into a new diet drug without acknowledging its discoverers.
"The lid must stay on the pot," Kruipeir said.
The case is one of several to be discussed at the World Summit for Sustainable Development as examples of the difficulties indigenous people encounter when they try to cash in on medicines they have used for generations.
The San, who number about 100,000, live in the region of the Kalahari Desert of southwest Africa where the hoodia, which they call xhoba, is native.
Light green and covered in thorns, the plant grows in clumps and is roughly the same size and shape as a cucumber. For as long as the San can remember, the bitter-tasting plant has kept them from feeling hungry on long journeys when they had little food or water.
'Part of a pattern'
Normally the patent system protects individual achievements before they become public knowledge. But indigenous people say the system should protect them for knowledge they contributed to the public domain.
The issue "is part of a pattern of being exploited relating to their lands, their rights. It can't be looked upon in isolation. It is an indigenous peoples' human rights issue," said Gerard Bodeker of Oxford University's Medical School and chairman of the Global Initiative for Traditional Systems of Health.
The San case started when researchers at the Council for Scientific and Industrial Research, a South African laboratory partly funded by the government, patented P57, the appetite suppressant derived from the hoodia, without acknowledging the San.
The lab then licensed P57 to the small British pharmaceutical company Phytopharm, which said the San clan that discovered the hoodia had died out, and subleased the patent to Pfizer.
Eventually that San clan, which had been relocated by the apartheid government but was very much alive, found out about the patent. After legal wrangling, an agreement on royalties was reached.
Richard Dixey, chief executive of Phytopharm, said there had been a misunderstanding about the clan's existence and praised the lab for coming to terms with the San.
"It's not an exploitation story," he said. "I don't think any party was trying to avoid a royalty-sharing agreement."
As for the San, although they remain annoyed that, in their view, they were almost swindled, they can't help but be amused by the prospect of Westerners using the hoodia plant to slim down.
"It wasn't used for that in my ancestors' days," Katerina Rooi, 69, said as she scrambled over sand dunes gathering hoodia stems.