MORPHOLOGICAL AND HISTOLOGICAL STUDIES OF CHINESE EPHEDRA MAHUANG Ⅰ.SEVEN SPECIES PRODUCED IN NORTH CHINA

The Chinese drug Ma Huang, Herba Ephedrae, is well known in the East and West. The botanical origin specified in the Chinese Pharmacopoeia (1085 edition) includes the dried herbaceous stems of Ephedra sinica Stapf, E. equisetina Bunge and E. intermedia Sehrenk ex Mey.. A survey of the botanical origin of this drug, however, revealed that other Eqhedra spp. are also used in certain districts in China. In order to find means for the identification of drugs derived from different plant origins, it is necessary to make a comparative study of the morphology and histology of all the Eqhedra spp. growing in China.In this paper, the morphological and histological characters of the crude drugs derived from the Eqhedra spp. chiefly growing in north China, viz. E. sinica Stapf, E.equisetina Bunge, E.intermedia Schrenk ex Mey., E.qrzewaskiistaqs E.monosperma Gruel. ex Mey., E. fedtschenkoae Pauls, and E.regeliana Florin are described, compared and illustrated with line drawings. It is discovered that the following characters are useful for their differentiation, viz.(1) the presence, shape and height of cuticular papillae of the stem; (2) the presence, amount and arrangement of sclereids at stem-nodes; (3) vessels and tracheids with bordered pits and spiral thickenings, tracheids with bordered pits and reticulate thickenings, and xylem parenchyma cells with reticulate thickenings, (4) the ratios of longitudinal and transverse diameters of stomata on the epidermis of stem and leaf.Observation with scanning electron microscope (SEM) revealed that the perforations of the end walls of vessel element in Eqherda spp. are bordered.It is also found that the degree of lignification of fibres and medullary cells of the herbaceous stems is related to the positions and diameters of the stems. It is therefore unsuitable as a diagnostic feature for the differentiation of Eqhedrra species.