Studies of Ephedra plants in Asia. Part 6: Geographical changes of anatomical features and alkaloids content of Ephedra sinica.

Ephedra sinica Stapf is the main botanical origin of the Chinese herbal drug Mahuang, Ephedra Herb. Eighty-five samples of E. sinica, collected across eastern China, Mongolia, and Buryatia (Russia), were studied anatomically and chemically to elucidate the local variations and the relation between environmental factors and the variations. The results showed that samples grown in more arid conditions tended to have a more sinuous epidermis, more cuticular tubers, and more subepidermal fiber bundles anatomically, and contained more total ephedrine alkaloids. These samples also had a high pseudoephedrine content. These results imply that Ephedra Herb with good quality should be collected from arid fields, and the chemical quality can be estimated by observing the anatomical characteristics.