Based on extensive field work , 282 fern species , belonging to 119 genera in 50 families , were recorded in Yinggeling Nature Reserve , Hainan Island , China . Among the 282 species, eight are new records to Hainan , i. e . Alsophila denticulata , Arachniodes amoena , Athyrium wangii , Dictyocline wilfordii , Dryopteris tenuicula , Phlegmariurus taiwanensis, Pronephrium megacuspe and Pseudophegopteris pyrrhorachis . The fern flora of Yinggeling is very rich and contains 89 . 3% families , 84 . 4% genera and 62. 7% species of the fern flora of Hainan Island . This flora is characterized by tropical distribution elements, represented by 97. 3% tropical families, 88. 3% tropical genera and 63.4% tropical species. Besides the tropical elements, local endemic and East Asia distribution elements are also prominent components . The four species-rich families with more than 20 species are Polypodiaceae , Athyriaceae , Thelypteridaceae and Aspleniaceae, and the five species-rich genera with more than 10 species are Asplenium, Pteris, Allantodia, Selaginella and Cyclosorus. Regarding the ecology of the fern flora , four major habitats can be identified: arid forest or shrub habitat at low altitude, dense forest habitat at middle and high altitude , humid ravine forest habitat at middle and high altitude , and mossy dwarfforest habitat at high altitude . Pteridophytes are mostly abundant in humid ravine habitat at middle and high altitude . According to 2001 IUCN Red List and Categories , 56 fern species are threatened in Hainan Island , i. e . four species are Critically Endangered (CR) ( i . e . Athyrium hainanense and Helminthostachys zeylanica ) , 17 species are Endangered ( EN) and 37 are Vulnerable (VU) . In addition , ten fern species are under Class II National Protection in China .