PHARMACOGNOSTICAL STUDIES OF THE CHINESE DRUGS PAI-CH'IEN AND PAI-WEI——Part I.A Critical Study of the Botanical Origins of the Commercial Samples

Pai-ch’ien and Pai-wei are two different drugs commonly used in the Chinese medicine, the former is employed as an expectorant as well as a cough remedy,the latter as an antifebrile and diuretic.As the Chinese names have long been applied to different drug plants in different districts,much confusion are arisen about the genuine origin of the above named drugs.It is therefore necessary to collect as exhaustively as possible all the commercial samples of these two drugs used in this country together with their mother plants,in order to check their characters with the descriptions in the ancient Chinese her- bals. 97 commercial samples~* of these two drugs,some of which with botanical specimens attached,were collected from 19 provinces including 46 cities and municipal districts in China.Their botanical identity were established by a critical study of their macrospcopical, microscopical and botanical characters.In result,15 species of plant were identified and herewith,summerized in the following table. It is dear from the table that not only plants of different genus of the family Asclepiadaceae but also of different families are used as Pai-ch’ien and Pai-wei,and moreover,confusion of the names exists not only in different provinces but also within the same province. However,it can be noted in the above table that the most widely used Pai-ch’ien is obtained from Cynanchum stauntoni and C.glaucescens,and Pai-wei obtained from C. atratum and C.versicolor,all belong to the family Asclepiadaceae.This conclusion is further strengthened by a comparative study of the statements regarding these two drugs in the ancient Chinese herbals.Therefore,it is recommended that the Chinese names Pai- ch’ien and Pai-wei should be applied to the drugs derived from the four Asclepiadaceous plants as stated above and should not be further confused with each other,all the others may be regarded as substitutes and adulterants. Detailed botanical descriptions of the four species Cynanchum stauntoni,C.glaucescens, C.atratum,C.versicolor and brief descriptions of the other eleven species are given toge- ther with photograghs. Detailed descriptions of the macroscopical and microscopical characters of these drugs will be published later.