Figure 1: Chromatography of all the samples from eight different growing locations.

S1, Mei county, Shaanxi; S2, Diebu, Gansu; S3, Huzhu, Qinghai; S4, Jingyuan, Ningxia; S5, Yongdeng, Gansu; S6, Shangri-la, Yunnan; S7, Ningchi, Tibet; S8, Kangding, Sichuan.