sp. nov. (Pteridaceae), a new species segregated from .

is widely distributed in Eastern Asia and has high morphological variation. Some morphologically similar plants related to this species are difficult to distinguish. We showed that the new species from Taiwan, previously identified as , can be morphologically distinguished by its wide pinnae, larger terminal pinnae than the lateral pinnae in sterile fronds, and triangular basal segments of the lateral pinnae. It was confirmed that this species is phylogenetically separated from the other East Asian species, except for a morphologically distinct species , by means of chloroplast genes, and . The new species is named as , referring to its wide pinnae. Here, we provide a key to facilitate the identification of the morphologically similar species in Asia. The morphological descriptions, images, ecology, and distribution are also presented.