Abstract: The scientific name for Pai-tsiang (败酱) used nowadays is usually referred to either as patrinia scabiosaefolia Fisch. ex Link or as P. villosa (Thunb.) Juss., of the family Valerianaceae, but the botanical origin of the Chinese drug "Pai-tsiang" is in great confusion in its herbal names as well as in the present drug market. On a critical study of the ancient herbals, it is obvious that this drug is at least represented by five different plants: a) Tao Hung Ching's (陶宏景) "Ming I Pieh Lu" (名医别录) (452-536) pro- bably referred to P. villosa (Thunb.) Juss.; b) Su-koon's (苏恭) "Hsin Shiu Pen T'sao" (新修本草) (659) and Su-soon's (苏颂) "Tu Ching Pen T'sao" (图经本草) (1057) probably referred to P. scabiosaefolia Fisch. ex Link; c) the description given by Li Shi Chen (李时珍) in his "Pen T'sao Kang Mu" (本草纲目) (1592) on the said drug com- prised two different kinds of plants, one was apparently Sonchus brachyotis DC., family Compositae, and the other was probably the only white-flowered Patrinia - P. villosa (Thunb.) Juss.; d) the figures under the name "Pai-tsiang" given by Tang Shen Wei (唐慎微) in his "Chen Lei Pen T'sao" (证类本草) (1211) and Wu Chi Chun (吴其濬) in his "Chi Wu Ming Shih Tu K'ao" (植物名实图考) (1848) represented two other kinds of plants not mentioned by any previous herbalists. The results of a taxonomic study of the twenty specimens of commercial drug sold under the name "Pai-tsiang" in the present markets at twenty cities and districts be- longing to sixteen provinces and autonomous regions of China are given in the following table. Botanical descriptions of the plants are given accompanied by four illustrations.