Rich pickings

In Longreads

Wang-yag is crouched on a rocky hill at 5,000m, her face a few centimetres from the ground, when she spots the fungus. That isn’t such an easy task. It’s barely a few shades darker, and only slightly thicker, than the grey-brown grass around it. The 37-year-old nomad has been searching for nearly half an hour, a wide-brimmed hat shielding her face from the harsh sun. Now the small wrinkles around her eyes deepen as she smiles. She produces a pick-axe from the skirt of her thick canvas robe and heaves it above her head.

Behind her, the Tibetan plateau erupts into granite-coloured peaks. Below, Wang-yag’s yaks are small brown blotches on a green basin. In the distance lies Namser, the valley where she and her relatives have camped for five summers. Wang-yag used to spend her days there, tending animals, tidying her yak-hair tent and caring for her seven children. But now her family depends on income from this fungus. A medicinal mushroom that grows parasitically on a moth caterpillar native to the Himalayas and Tibetan plateau, Cordyceps sinensis is a rare and expensive Chinese medicine.

Last winter, fungus spores landed on a caterpillar and began to consume its body, slowly killing it. As it died, the caterpillar burrowed underground. Eventually the fungus overtook the body, sprouting through its forehead and out of the ground – producing the growth Wang-yag spotted. The lifecycle is contained in the Tibetan name: yartsa gunbu means “summer grass winter worm”.Wang-yag lets out a grunt and brings the pick-axe down just short of the fungus. Brushing away a clump of soil, she shows me a shrivelled L-shaped object. “Yartsa gunbu,” she says proudly. Cordyceps.

In Chinese medicine, caterpillar fungus is known as something of a wonder-drug. Boiled in soup or eaten whole, it is said to aid every ailment from immune deficiencies to erectile dysfunction.

Recently, Cordyceps has received attention further afield, as enthusiasm grows in the west for traditional Chinese medicine, or TCM. Since the 1980s, the UK has become traditional medicine’s leading consumer outside of Asia, with an estimated 3,000 clinics nationwide. The NHS already covers Chinese medicine for some patients in Northern Ireland and the Department of Health is exploring regulation of TCM.

Cordyceps is incorporated into several western products, such as Origins’ Mega-Mushroom skin creams and Steven Seagal’s Lightning Bolt energy drink. Demand is also rising in China, where chongcao, or “worm-grass”, is rolled into cigarettes, turned into elaborate dishes at special caterpillar fungus restaurants, and used to bribe officials. Prices, in turn, are skyrocketing. One kilo of prime Cordyceps now draws Rmb300,000 – more than £19,000.

In Wang-yag’s native southern Qinghai, an ethnically Tibetan area on the northern edge of the Tibetan plateau where annual income is Rmb2,165 (£139), that makes the fungus indispensable. In late May and June, when bu, as it is known, is mature, schools close so that children can help with the harvest. Some businesses go on holiday, while others stay open in anticipation of the cash the medicine brings in. In Dzato, the county that contains Namser, the local government regulates the trade by levying picking taxes, issuing permits and setting a start date for the harvest. Checkpoints close off the area, and I was only let through because our translator was a local.

When Wang-yag returns to her tent after a day of picking, her husband, Sonam Rrichen, is there waiting. A loud man with darting eyes, he spends most of his free time polishing his motorcycle, which he bought this spring with Cordyceps money. Wang-yag hands him her bu, and he combines it with his own, collected in the hills surrounding a relative’s tent. He counts: 20 caterpillars in two days. That’s one caterpillar every 90 minutes, a tedious pace. But he seems pleased. Each caterpillar fungus will draw between Rmb20 and Rmb50 (£1.30-£3.25).

Chinese doctors date the use of caterpillar fungus to the Tang dynasty (618-906), suggesting that trade with Himalayan nations extends back that far. The earliest known Tibetan record is from the 15th-century “Instructions on a Myriad of Medicines”, in which doctor Namnyi Dorje explains Cordyceps’ uses in florid verse: “It removes prana diseases, cures bile diseases and does not raise the phlegm; a marvelous medicine / In particular, it especially increases semen / It is a flawless treasure of an ocean of good qualities.”

By the 1800s, the Tibetan region of Kham (which encompassed Namser before Chinese occupation) was exporting 10 tons of bu a year. In the 1920s, Namser elders recall, their parents and grandparents encountered Chinese traders looking to purchase Cordyceps on their way back from Tibet. Trade continued through the 1949 revolution, the 1959 Tibetan uprising and the Cultural Revolution. But it wasn’t until economic reforms brought rising incomes to China in the 1980s that demand soared. In some parts of Tibet, Cordyceps now accounts for an estimated 80 per cent of rural income.

In 1998, German ecologist Daniel Winkler was studying forest-related income in Tibet when he heard about the bu trade. “When we talked about rural cash income,” he says, “everybody kept mentioning caterpillar fungus. Nothing touches it in cash value.” He began spending summers with pickers in greater Tibet. Today Winkler, who is responsible for much of the research on Cordyceps collection, advises US medicinal mushroom companies on developing products.

For nomads in Dzato, the success of Cordyceps has meant an introduction to modernity. They now buy canvas shoes instead of making boots from yak hide and the children eat candy and instant noodles.

Although Cordyceps was harvested in past centuries, Buddhism held that it disturbed earth spirits and its collection was taboo. Sonam Rrichen recalls an old saying: “Picking one bu is like killing 18 men.” Today, only monks and nuns abstain. In parts of the plateau where the harvest is less regulated, some people begin picking in early May, before the fungus is mature. Others don’t replace the soil they dislodge, exacerbating erosion, already a serious problem.

Increasingly, the harvest also leads to conflict. In Sichuan, Tibetans clashed over picking rights in July, brandishing semi-automatic rifles and grenades in a conflict that killed six and left 100 wounded. Earlier in the season, in Nepal, 16 people died while trying to pick during a blizzard. And in 2005, when nomads from neighbouring Nangchen ventured on to Dzato land to search for the fungus, the government reacted by taxing the outsiders while the locals blockaded the county’s main road. Nangchen pickers broke through the barriers, prompting a two-week clash in which houses were razed, stores looted and at least one man died.

When Sonam Rrichen and Wang-yag need money, they take their caterpillar fungus to Jyegu. As a county seat, Jyegu boasts a provincial glamour: a hotel, a bar and restaurants. During Cordyceps season, the town is bustling, its central square – a broad plaza guarded by a bronze yak – packed with traders. There are Hui Muslims in white pillbox hats, monks in maroon robes apparently ignoring Buddhism’s stance on the trade, and ragtag speculators, who buy when the fungus is cheap and sell when it is expensive. Women and old people sit on the ground, cleaning bu with toothbrushes. The biggest traders hold court around the yak. Deals are done silently, through a series of complex handshakes meant to prevent observers from learning the price.

From Jyegu, the traders take bags of fungus to the Fur Market in Xining, the provincial capital, where an entire street is devoted to the trade. In the early 1980s, China’s economic reforms made it possible to freely buy and sell the fungus and export it to Hong Kong. By the middle of the decade, the market housed rows of wholesale shops.

Ma A’hu, a Muslim with a long grey beard, is one of the street’s oldest and most respected traders. Every few weeks he sends his nephew, Zhou Zhongyuan, to Shanghai to deliver his fungus. On one trip, Zhou received a text message mid-way to Shanghai reporting that the price had doubled in Xining. Zhou bought up as much Cordyceps as he could find where he was and backtracked to Xining to sell it at a profit.

But even with the prospects for speculation, Ma and Zhou are pessimistic. “The price is too high now,” Ma says. “We’re not making any money.” Since he started trading 20 years ago, the price has jumped tenfold. Caterpillar fungus, it seems, is disappearing. When Wang-yag started picking 24 years ago, she found 200 to 300 fungi a day (older relatives remember picking 1,000). Now she finds 10 on a good day. Last year, Indian zoologists documented a 30-50 per cent decline of the fungus over a two-year period in villages in the Indian Himalayas. This year, Chinese ecologist Yang Darong found that Cordyceps numbers in western China have fallen to between 3.5 and 10 per cent of their totals from 25 years ago.

Cordyceps releases millions of spores through its “tail” beginning in May. The spores fly off in search of caterpillars, which they attack and consume throughout the year. Premature and heavy collection seems to reduce the chances of regeneration. Also, unlike other medicinal mushrooms, Cordyceps’ survival depends on a supply of caterpillars. Some researchers speculate that degradation of the grassland may be reducing insect populations. “We’re killing the chicken to get its eggs,” Yang says.

Winkler, who leads foraging expeditions to greater Tibet, is sceptical of Yang’s numbers, saying his estimates from 25 years ago appear too high. He says Tibetans find fewer fungi now because the number of pickers has increased – and points out that the fungus has managed to regenerate itself for centuries. “Sustainability is a big issue,” he says. “But we don’t have reliable data yet.”

Scientists agree, nonetheless, that better oversight of the harvest and the establishment of Cordyceps reserves could boost its chances of survival. Winkler advised Tibetan officials on regulating the trade in 2005. Tibetan pickers, meanwhile, are caught in a vicious cycle: as prices increase, collection becomes all the more irresistible.

As worries about the sustainability of Cordyceps increase, finding a substitute has become a priority in China and abroad. Researchers have isolated polysaccharides that they believe are the active ingredients. Several companies have reproduced these by culturing the fungus in liquid or on grains of rice, wheat or barely, creating a caterpillar-free “cultivated” Cordyceps.

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But according to Wang Hongsheng, an animal scientist at Qinghai University who has worked on replicating Cordyceps, current versions of cultivated, or mycelium, fungi are not a substitute for the real thing. The wild fungus is a complex combination of polysaccharides, and scientists can only replicate certain aspects of that mixture. And while cultivated Cordyceps can be produced in a week, its creation is complicated by other factors. “You would think you take the fungus, put it in a Petri dish, and you get Cordyceps sinensis, right?” says Winkler. “Not right. Many different species grow out of that mycelium.”

In the west, where many consumers are happy not to be eating caterpillars, many TCM distributors use mycelia. But others sell the wild fungus, which they obtain through Hong Kong middlemen and market as a product of the Tibetan highlands. When I ask Sonam Rrichen where his Cordyceps ends up, he says: “China. Europe. America.” He looks at me sideways. “Maybe that’s why you’re here?”

In the UK, wild Cordyceps – ground into powder or measured into capsules – is available from TCM clinics and retailers but also sold from storefronts on the high street. AcuMedic, a popular London clinic that treats mostly non-Chinese, sells the whole fungus, which it obtains directly from a dealer on the plateau. But clinic founder Man-fang Mei says that as the fungus’s price rises, many of his patients can no longer afford it. “It’s becoming scarce in supply,” he says. “A kick of it” – several hundred grammes, enough to have any effect – “will cost you a few thousand pounds.”

On our last day in Dzato, Wang-yag’s oldest daughter, 11-year-old Dechen Yang-gar, wakes up with a stomach ache. Sonam Rrichen decides to postpone his picking trip to take her to the doctor on his motorcycle. The photographer with whom I’m travelling looks at the girl’s face and offers them a ride in our Jeep.

The road to the doctor’s house winds past rolling hills, clear streams and grazing yaks. Rounding a bend, we encounter cliffs covered with colourful Buddhist thangka paintings and scripture in graffiti-style bubble letters. Eventually we stop near a collection of squat cement homes surrounded by a yak dung fence. The doctor, a man named Gang-jya with salt-and-pepper hair and a bad leg, leads us into a dusty room.

The girl sits silently while Gang-jya thrusts a crusty thermometer under her arm, takes her pulse and examines her eyes and tongue. He limps to a bed and measures out portions of eight herbs from small sacks. Then he sits on a stool beneath an altar adorned with fake flowers and portraits of lamas, mixes the herbs on a sheet of paper and folds it into a neat triangle. The diagnosis: “gall bladder problems”. “Instructions on a Myriad of Medicines” recommends boiling bu with sheep’s milk, sparrow’s chest, and “fine snow lizard”, drying the liquid, and grinding it into a fine powder. The medicine is best consumed at dawn with strong alcohol. More recently, Tibetans have shortened that process, taking Cordyceps floating in a shot of stiff barley liquor. But when I ask Sonam Rrichen whether his family eats bu, he laughs. “It’s too expensive.”

Back in Namser, Sonam Rrichen locates a patch of sunshine outside the tent. His motorcycle is parked nearby, a vinyl cover protecting it from plateau snowstorms. He empties the herbs onto a flat rock, mashes them with a smaller stone, and takes the mixture inside, where he boils it with water over a yak dung stove and pours the concoction into a bowl for Dechen Yang-gar to drink. Then he leaves to pick Cordyceps.

First published in Financial Times.


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Mara Hvistendahl
Mara Hvistendahl is a contributing correspondent at Science magazine and the author of Unnatural Selection, a finalist for the Pulitzer Prize and the Los Angeles Times Book Prize. Mara has written for The Atlantic, Harper’s, Scientific American, Popular Science, The Wall Street Journal, and Foreign Policy. A longtime correspondent in China, she now lives in Minneapolis.