| Abstract | Jiaomu, a traditional Chinese medicine used as a diuretic, is derived from seeds of members of the genus Zanthoxylum , and is of the same origin as Huajiao. It is difficult to identify Zanthoxylum seeds due to similarities in their external morphology and the difficulty of sectioning them to observe their internal structure. A new anatomical method, using a scanning electron microscope and an image analysis system, was used to study the seeds of 16 species, 3 varieties and 1 form, collected from China, Japan and Nepal. The results showed that the species and varieties could be distinguished from one another by the following characteristics: number of layers of epidermal cells, ratio of radial diameter to tangential diameter of the epidermal cell, shape of the closed curve drawn between the epidermis and sclerenchyma tissue (its degree of roughness shown by SFC value), the ratio of the average thickness of the outer mesophyll to the inner mesophyll, the ratio of occupation of epidermis to outer seed coat, the ratio of the thickness of the outer seed coat to the radius of transection of the seed, etc. Commercial samples of Jiaomu obtained from Shanghai and Datong (Shanxi) markets were the seeds of Z. bungeanum [ Z. simulans ], and that obtained from Huhehaote (Inner Mongolia [Nei Menggu]) market was a mixture of seeds and pericarps of Z. schinifolium . |