[Morphological and histological studies of Chinese Ephedra, ma huang. II. Species produced in southwestern China and other species].

In this paper, the morphological and histological characters of crude drugs derived from Ephedra likiangensis Florin, E. likiangensis f. mairei (Florin) C. Y. Cheng, E. saxatilis Royle ex Florin, E. gerardiana Wall, E. gerardiana var. congesta C. Y. Cheng, E. minuta Florin, E. minuta var. dioeca C. Y. Cheng, E. lepidosperma C. Y. Cheng, E. lomatolepis Schrenk and E. intermedia var. tibetica Stapf are described, compared and illustrated with line drawings. It was found that all the Ephedra spp. growing in southwester nChina possess the following features in common, viz. (1) numerous distinct longitudinal ridges are present on the stem; (2) xylem fibres and tracheids possess steep, tertiary spiral thickenings; (3) stone cells (sclereids) are absent from the nodes. According to the above characters, the drugs produced in southwestern China can be differentiated from those produced in northern China. The results also show that the histological characters of E. intermedia var tibetica Stapf produced in southeast ern Xizang (Tibet) are different from those produced in north western Xizang. The former possesses the xylem fibres and tracheids with steep, tertiary spiral thickenings, while the latter possesses sclereids at stem-nodes. It may be related to their habitat factors and interspecies hybridization. A key for identification of all the crude drugs derived from Chinese Ephedra spp. studied in this series of paper, including thirteen species, three varieties and one form is presented.