Abstract: Bupleurum is a genus largely distributed in temperate regions of the Northern Hemisphere. In China 36 species, 17 varieties and 7 forms have hitherto been reported and most of them are used as Chinese traditional drugs under the name of Chai-Hu. Chai-Hu is one of the most popular drugs used ever since the ancient time and is prescribed principally in the treatment of fevers and influenza. In this article, the authors report two new species, B. kunmingense Y. Li et S. L. Pan and B. polyclonum Y. Li et S. L. Pan which were discovered in Yunnan Province based on morphological studies and preliminary phytochemical tests. The ultraviolet spectrums and thin layer chromatograms of the essential oil and the crude saikosaponins of the two new species are similar to those of B. chinense DC., the standard material medica of Chai-Hu. Moreover, two new saikosaponin spots located between saikosaponin a and c in TLC were discovered in the two new species, and this could be served as a chemical evidence for identification purpose. In the histochemistry examination, the reaction of saikosaponin with color developing agent in parenchyma of the roots of the two new species is obviously more significant than that of B. chinense DC. and this phenomenon has also been proved to be true by TLC of the crude saikosaponin extracts of these two new species. It is suggested that the two new species be used as a substitute ofhigh quality for Chai-Hu.

Key words: Bupleurum Kunmingense, B. polyclonum, essential oil, saponin