Systematics of the Fern Genus Didymochlaena (Didymochlaenaceae)

Abstract

Abstract The fern genus Didymochlaena is characterized by having scaly rhizomes and petioles, tufted and bipinnate leaves, dimidiate pinnules, and fewer than 11 sori per pinnule. For a long time only one species was widely recognized in the genus. Most recently, six and seven species from Madagascar and Asia-Pacific regions, respectively, have been recognized based on morphological and/or molecular evidence. In this monographic study we recognize 22 species worldwide, six of which are described as new: D. alpina, D. amazonica, D. cameroonensis, D. comorensis, D. cubensis, and D. mesoamericana. A key to all species is provided, and detailed descriptions, illustrations, and information on their distribution and habitats are given.