Among them , some species are indicating plants for pollution , some have natural chemical materials that can resist bacteria and virus . they have promising exploit prospect . the thesis is principally based on the investigation , collection of the specimens and the identification of more than 5000 packages of pleurocarpous mosses collected by us in hebei province from 1995 to 2001 研究结果表明，河北省侧蒴藓类植物区系成分可划分为9类，其中，北温带成分占主导地位，共计98种，占总种数的50 . 79 ；东亚成分占很重要的位置，共计54种，李秀芹：河北省侧葫茸类植物研究2占总种数的27
