Merchants are busy trading caterpillar fungus at the Jiuying market in the Hui ethnic group community of Xining, NW China’s Qinghai Province on Monday. Caterpillar fungus, known as "worm grass" in China is used in traditional Chinese medicine that is only found in high-altitude regions, especially the Qinghai-Tibet Plateau. The market price for 500 grams of top caterpillar fungus is usually $16,000. (Photos: Li Hao/GT)