Pteridophyte flora in remnant monsoon forest from valley of the Hongshui River,Guizhou Province

By line transect method,we investigated fern resources in a remnant monsoon forest from a valley of the Hongshui River in Guizhou Province,and did cluster analysis to compare this flora with other 12 areas.There were 178 species(including varieties and forms) of fern,which belong to 67 genera in 30 families.The dominant families were Polypodiaceae,Thelypteridaceae,Selaginellaceae,Pteridaceae,Athyriaceae,Aspleniaceae,Aspidiaceae,Dryopteridaceae,and Adiantaceae and genera were Selaginella,Pteris, Cyclosorus,Adiantum,Allantodia,Asplenium,and Colysis.In this area,flora of the fern genera consisted of plants found throughout the world as well as those from the tropical,tropical to subtropical,subtropical,temperate,and East-Asian zones.For those genera that were not spread throughout the world,the 26 dominant genera from the tropical to subtropical zone accounted for 44.83% of the total.The flora of the fern species included those found throughout the world,in addition to those from tropical,tropical to subtropical,temperate,and East-Asian zones along with those endemic to China.Excluding genera that were spread throughout the world,the dominant species were from the tropical to subtropical zone(103 species) and accounted for 59.54% of the total.Additionally,for pteridophyte flora composition,cluster analysis results indicated that this area most closely resembled Nanshan District in Shenzhen,Guangdong Province.