discovered recently in Yangtze River valley is a narrowly distributed species endemic to the water-level-fluctuation zone in Three Gorges Reservoir Area of Changjiang River.After an exhaustive investigation,we found P.fengdouensis
only grown in three potamic islands in the border of Fengdu and Zhongxian and Banan counties of Chongqing City and a total of 290 plants were identified.The construction of Three Gorges Dam will raise the water level and submerge the entire natural habitats and all wild populations of P.fengdouensis
in 2006.To conserve this rare and endangered plant,we thoroughly investigated its natural distribution,ecological characters and community structure.The morphological characteristics,annual growth cycle and reproductive value of P.fengdouensis
were compared with cogeneric widespread species P.asiatica
.The results showed,the main reasons for limited individuals and endemic distribution of this species were prolonged fruiting period,short distance of seed dispersal,low reproduction value and frequently interference by flooding.Further research in ex situ conservation strategy is discussed and as well as urgent conservation efforts are proposed.