It looks like a small brown twig growing out of a caterpillar shell.

To the seriously ill who put their faith in traditional Chinese medicine, the caterpillar fungus promises the possibility of continued life.

But to the herding families who pluck the rare fungus from the sheer slopes of the Tibetan plateau, it can easily mean an early death.

"The slopes are steep," says 13-year-old Wuge with a smile. "You can see the corpses of the unskilled fungi diggers who have fallen."

This year, he and his family will have an extended stay on the bluffs as they seek to recover some of the losses they suffered in the earthquake that rocked west China's Qinghai Province April 14.

"Usually we stay there for a whole month, and my father sells the fungi to traders when we return to Gyegu."

He says the family plans to camp out in the fungi-growing slopes earlier than the usual start of the harvest season in late May.

"Last year, we made about 20,000 yuan, but this year we definitely need to dig more," Wuge says.

Home for the boy's family is now one of the many blue tents pegged out in the dusty field that formerly served as the horse-racing track in the the remote town of Gyegu.

Most of the town was flattened in the 7.1-magnitude quake that struck the Tibetan Autonomous Prefecture of Yushu and left around 2,220 people dead and more than 100,000 homeless.

The barren field, surrounded by mighty mountains, has become an encampment for tens of thousands of survivors.

Sitting at a make-shift kitchen on the rubble, Wuge's 77-year-old grandmother chants Tibetan Buddhist prayers, staring at the rubble of the family's mud-brick houses.

"She doesn't want to talk. She is sad," says Wuge.

His family's tent also houses his three cousins, who all lost their fathers in the quake, and their mothers -- another reason why his father must make more money.

Like most herdsmen and farmers here, Wuge's family has relied on the annual harvest of the caterpillar fungus to survive. Locals say the earthquake is likely to push them to a desperate hunt for the plant, which already faces extinction.

The caterpillar fungus only grows on the remote mountains on the Tibetan plateau. It's Chinese name – dongchongxiacao – literally means "winter worm, summer herb."

Ground into a powder, the fungus is a valuable ingredient in traditional medicines and is believed to boost the immune system. Cancer patients usually take caterpillar fungi when they undergo chemotherapy, says Tsering Wom-tso, president of Yushu Tibetan Medicine Hospital.

China can produce an estimated 200 tons of caterpillar fungi every year, 70 percent of it from Qinghai.

Its rarity pushes up market prices in big cities like Beijing and Shanghai to around 100,000 yuan per kg, but those prices have also driven the over-harvesting, which many say has put it in danger.

While China's middle and wealthy classes consume caterpillar fungus for their health, impoverished farmers put their religious beliefs, the eco-system, and even their lives on the line to harvest the fungus.

Konchok Thubsang, a senior monk with Sershul Monastery near Yushu, says Tibetan Buddhism does not allow the harvesting of the caterpillar fungus, but most local households have no alternative.

Many Yushu quake survivors told Xinhua they plan, like Wuge's family to make an early start on this year's harvest.

Drochi, 44, says he needs to sell more fungi to buy food and maybe build a new house.

"We don't have a place to stay. But I don't know if it is wise to build a new house. If another earthquake comes, it will collapse again," he says.

Cairangwencuo says the caterpillar fungus accounts for 80 percent of most local families' annual incomes. A poor harvest coupled with a catastrophe could doom the hopes of many rural poor.

And that fear is not unfounded.

"Usually the more rain, the more fungi. But we have not had good rain this year, so I seriously doubt if we will have a harvest at all," says Cairangwencuo in a tent filled with medicines and a hospital bed, which has become a make-shift clinic in Gyegu's sports field to treat quake injuries.

"With aid phasing out in the second half, life might get worse."