Ephedra resource in Sichuan and Yunnan Provinces 2007.

Wild Ephedra plants growing near the Tibetan border of Yunnan and Sichuan Provinces and north-central Sichuan were surveyed and their DNA and ephedrine alkaloids content were analyzed. By analysis of internal transcribed spacer 1 (ITS) 1 DNA, E. likiangensis was found to be the dominant species in these regions, which clustered into 2 major groups in the phylogenic tree. Most Ephedra plants in these regions of ordinal size contained ephedrine and pseudoephedrine of more than 0.7%, the requirement for Japanese Pharmacopoeia 15th edition, suggesting that they have potential for crude drug production of Ephedra herbs.