Preliminary investigation in Pteridophyte of Danxia Landform in North Guizhou,China

Based on the investigations by the authors and the records in literature,the floristic characteristics of pteridophytes of Danxia landform in the north area of Guizhou Province was studied in the present work.The results demonstrated that the area was abundant in species of pteridophytic flora,including 303 species(varieties),96 genera,and 41 families.among which Athyrium araiostegioides was newly recorded in Guizhou.There were some dominant families and genera,e.g.families Dryopteridaceae,Athyriaceae,Polypodiaceae,Thelypteridaceae and Aspleniaceae.Complex geographic distributions of pteridophytes were observed,among which 63 genera are tropical-subtropical distribution types,accounting for 65.6% of the total,indicating that the fern flora at genus level were characterized by tropical and subtropical nature.At species level,East Asia element(139species) took the largest proportion,accounting for 45.9% of the total,which suggested that the fern flora is of the East Asia.The genetic relationship of fern flora in this area was more close to that of Leigong Mountain than that of Libo County.