Authentic wild Dendrobium is produced in southwest Anhui (Dabie Mountain), east Zhejiang (Yinxian, Tiantai and Xianju), west Fujian (Ninghua), northwest Guangxi (Tiane), Sichuan (location unknown) and southeast Yunnan (Shiping, Wenshan, Malipo and Xichou). Dendrobium stems are cylindrical, with a height of 15 ~ 50 cm and a diameter of 4 ~ 8 mm. The leaf sheaths are fleshy, oblong and lanceolate, with a length of 3 ~ 6.5 cm and a width of 0.8 ~ 2 cm, and the tips are slightly hooked. Racemes are born in the middle of leafless or leafless stems with 2 ~ 4 flowers; The flowers are yellow-green, slightly fragrant; Sepals length 1.2 ~ 2 cm; Petals are shorter than sepals, and the labellum is ovate-lanceolate, with a length of 1.3 ~ 1.6 cm and a width of 7 ~ 9 mm. The apex is tapered or short, with a round purple patch near the middle of the upper part and a yellow corpus callosum near the middle of the lower part. The flowering period is from April to June.