白洋淀的水生维管束植物

白洋淀重新蓄水后维管束植物区系组成已完全恢复，现记录有１９科３２属４６种。金鱼藻科、花蔺科、茨藻科、菱科、浮萍科和睡莲科在本区系中占有重要地位。区系的地理成分以世界分布属居首（２９．１％），其次是泛热带分布属（１９．４％），北温带分布属居第三位（９．７％）。有４个生态类型：挺水植物（４１．３％），浮叶植物（１７．４％），漂浮植物（８．７％），沉水植物（３２．６％）。

Studies on the Vascular Plant in Lake Baiyaugdian

This paper is a report of the studies on the vascular plant in LakeBaiyangdian. The results show that flora elements of vascular plants all return to the normalafter storing water in 1988. There are 46 plant species which belong to 19 families 32 generain the Lake Baiyangdian. The main families of the flora are Ceratophyllaceae,Butomaceae, Najadaceae, Trapaceae, Lemnaceae and Nymphaeaceae. In the geographi-cal elements of the flora the genera of the world distribution are the largest proportion(29.1%), the genera of the general tropical distribution are the second (19.4%)and thegenera of the north temperate zone distribution are the third(9. 7%)in the LakeBaiyangdian.