Hymenophyllum subg. Hymenophyllum (Hymenophyllaceae) in the Atlantic Forest Domain, Brazil: Phylogenetic Relationships and Taxonomic Review

Abstract A revision of the species of Hymenophyllum subg. Hymenophyllum in the Brazilian Atlantic Forest domain is presented. Morphological and molecular analyses were performed based on herbarium material and samples collected during fieldwork. Molecular analyses were performed with data of the plastidial markers rbcL, rbcL-accD, rps4-trnS, and trnG-R. The results demonstrate the existence of three distinct and independent lineages of H. subgenus Hymenophyllum in the Atlantic Forest domain. Three taxa were recognized: H. fucoides, H. megachilum, and a new species, H. bradeanum, endemic to the Itatiaia Massif, southeast Brazil. Distribution maps, identification keys, descriptions, and illustrations are provided, together with a preliminary update of the conservation status of the species.