[Morphological and histological studies on the Chinese drug shan-dou-gen]

The Chinese drug "Shan-Dou-Gen" has been used for removing toxic heat, promoting the subsidence of swelling and soothing the sore throat since the ancient time. The authors made a survey of the drug "Shan-Dou-Gen" available in drug markets as well as the plant origin from the drug producing districts. The results showed that the drug "Shan-Dou-Gen" used in different regions in China at present are the roots or rhizomes derived from 9 species: Sophora tonkinensis Gagnep. (Leguminosae), Menispermum dauricum DC. (Menispermaceae), Indigofera amblyantha Craib (Leguminosae), I. carlesii Carib, I., fortunei Craib, I. decoa Lindl. var. ichangensis Y. Y. Fang et C. Z. Zheng, I. kirilowii Maxim. et Palibin, I. potaninii Craib, and Beesia calthaefolia (Maxim.) Ulbr. (Ranuculaceae). In this paper, the morphological characters of the crude drugs are described, compared and illustrated with photographs. The histological structures of the used parts are described, compared and illustrated with line drawings. The morphological and histological similarities and differences found among the above 9 species are summarized, and the key for the identification of the crude drugs is provided. As the drug "Shan-Dou-Gen" derived from different species has different actions and dosages, it is necessary to give different names to different species and use them correctly.