My girlfriend has mentioned this "plant" to me a few times, but I didn't believe what she was talking about.
YAJIANG - Amid towering mountains stretching from western China into Tibet, a tiny fungus is luring herders into a feverish treasure hunt that promises wealth to people who have often been bystanders at China's economic party.
At a mountain pass more than 4,000 metres (13,000 feet) above sea level outside Yajiang County in Sichuan province, a herder, Tangba, and a dozen other men have joined tens of thousands of Tibetans hunkered on treeless slopes across the region, squinting for signs of what Chinese call "worm grass" -- a prized medicine.
"You can become rich if you're lucky, make a bit of money if you're not, but it's not easy," Tangba said, clutching a jar half-filled with shrivelled, yellowish stalks. "That why Tibetans are best at it. We know our home."
"Worm grass" is not really a plant. Known by Tibetans as "summer-grass winter-worm", it forms when a parasitic fungus hijacks and devours the bodies of ghost moth larvae that have burrowed into the alpine soil for up to five years. It then steers their bodies to the surface so it can spread its spores.
The mummified moths, two inches or more long, are a traditional Tibetan cure-all that promoters say helps fight AIDS, cancer and ageing. As Tibetan medical ingredients have won adherents in China and abroad, worm grass and other alpine fungi and plants have become lucrative commodities, luring almost entire villages on harvests from May to July.
"Now many families are going out to find it, just leaving the old people at home. I thought it was a bit crazy too, but I also want to make money," said Celang. He planned to quit his job in a Kangding town restaurant in western Sichuan to hunt fungi.
With luck, Celang said, he could make 2,000 yuan ($250) in a month or two, compared to 400 yuan a month in the restaurant.
At the mountain pass, Tangba and the other pickers set out every morning, scanning tuft-covered ground for tell-tale fungi shoots and, with a trowel or small hoe, cut carefully and deeply into the earth to avoid damaging the larvae corpse.
Sometimes they return to camp with dozens of the dirt-covered caterpillar fungi, at other times only a handful.
The hunt is enacted across large parts of Tibet itself, as well as neighbouring Sichuan and Qinghai provinces, providing a vital economic pump in many areas, Daniel Winkler, an environmental consultant and expert on the fungus based in Kirkland, Washington, told Reuters.
Children get special school holidays to go picking, officials go AWOL, and in some areas influxes of thousands of temporary pickers take much of the crop, sparking violence with locals and even killings, according to Chinese news reports.
Caterpillar fungus, which provides many Tibetan yak herders with about half their annual income, is a case of bottom-up business in a region dominated by grand development blueprints that have often failed to deliver at the grass roots, Winkler said.
"Without the income from caterpillar fungus, the whole place would collapse right now," he said of the local economy.
Pickers with larger hauls or higher hopes converge on markets like one in Litang, a far-western Sichuan town that recalled a Gold Rush outpost overrun by fungus hunters. On a recent Sunday, the main street was a crush of pickers and traders, with onlookers following deals as intensely as Wall Street brokers.
Tibetan and some Hui Muslim buyers flashed wads of 100-yuan notes, gestured bids, and peered at bags and baskets of fungi. Police had to break up a brawl, apparently between quarrelling traders.
Nomadic Tibetans have traded caterpillar fungus with neighbouring Chinese regions for centuries. But locals said booming domestic and international demand has made the annual hunt more intense, and enriched a class of Tibetan brokers.
China's exports of worm grass leapt to 4,795 kg (10,570 lb) in 2004, up 1,422 percent on 2003, said China's pharmaceutical administration. China produces about 20,000 tonnes of caterpillar fungus a year, according to one official estimate. Litang traders said domestic demand is growing by 10 percent or more a year.
"You can make good money in Tibetan medical herbs, but you need to know the market and the plants, and we're better at that than Han people," Tibetan trader Dimtsenema said in a Kangding nightclub, where he was celebrating a good week, dressed in a dark suit, red shirt and trimmed goatee.
But much of the annual crop eventually flows through mostly Han Chinese wholesalers in regional hubs, such as the Hehuachi traditional medicine market in Chengdu, capital of Sichuan.
A kilo today sells for 20,000 to 50,000 yuan, depending on quality and origin; five years ago, it sold for about half that; a decade ago, for 3,000 yuan, said Hehuachi stall holder Deng Yazhi. "The whole world wants it, so worm grass is like gold."
Commercial appetite for caterpillar fungus may, however, carry long-term costs, some environmental activists have warned. Swathes of Tibetan highland are being scoured of medical plants, leaving pock-marked mountain slopes vulnerable to erosion and possibly disrupting complex ecological rhythms, they have said.
Winkler, the environmental consultant, said the long-term consequences remain little understood but production seems not to have suffered so far and some warnings may be overblown.
Tibetan pickers said they worried most that growing numbers of people would continue crowding the grass lands for fungus.
"It's getting harder and harder to find worm grass," said Tsangpa, a herder who had travelled to Litang with a small bagful. "There's not so much to go around."
Story by Chris Buckley