Caolian is a crude drug which is derived from Coptis linearisepala T.Z.Wang et C.K. Hsieh. The officinal parts are rhizoma with leafstalks and laminaes. It is used as Coptis in Leibo and Mabian of Sichuan province, where are the proper growth regions of Caolian.C. linearisepala was first put forward as a new genus in 1980's. In this paper, the systematical Pharmacognostical study of Caolian is reported in order to offer some materials for authentication and classification.Original plants and medicinal mater...