Taxonomic studies of Cheiropleuria (Dipteridaceae)

Morphological and molecular studies are made on the fern genus Cheiropleuria, which was treated in the past as monotypic. We describe C. parva, a new species from Borneo, and separate C. integrifolia, distributed in Japan and Taiwan and probably in China too, from Southeast Asian C. bicuspis. The three species differ from each other in the size, shape and texture of lamina, divergence angles between lobes, frequency of bilobed leaves, and spore size and morphology. Cheiropleuria parva is distinct from C. bicuspis populations sympatric on Mt Kinabalu in the leaves of juvenile and adult plants, suggesting reproductive isolation. Nucleotide differences in the rbcL gene support separation of the three species.