[Microscopic identification study of western herbs. Part I: Three Echinacea-species roots].

Objective: To make microscopic identification research of three Echinacea-species roots recorded in the United States Pharmacopeia.Method: The root transverse section and powder of E.angustifolia,E.pallida,and E.purpurea were observed.The main microscopic features were photographed.Result: The main microscopic features of transverse section and powder in three Echinacea-species roots are basically similar,except for some diagnostic differences.The results provide reliable reference for the authentication of raw materials of western herbal studies.