A taxonomic revision of the eusporangiate fern family Marattiaceae, with description of a new genus Ptisana

Ptisana Recent phylogenetic investigations of marattioid ferns (Marattiaceae) have generated a refined understanding of genus- and species-level relationships within family. A taxonomic revision of marattioid ferns is presented here. This new taxonomy is congruent with the current understanding of the phylogeny of marattioid ferns based on both molecular and morphological data. Marattiaceae is recognized here in the broad and most commonly used sense, encompassing all extant genera. Marattia as traditionally defined is paraphyletic, and is split here into three morphologically distinct and monophyletic genera: Marattia s.str. is restricted to the Neotropics and Hawaii; Eupodium, a distinctive Neotropical genus that has not been recognized by recent authors, is resurrected; and a newly described genus Ptisana comprises the Paleotropical species. Angiopteris is circumscribed broadly to include Archangiopteris, Macroglossum, Protomarattia, and Protangiopteris. Neither Danaea nor Christensenia require changes to their circumscriptions. As Marattia s.l. is undergoing the most drastic change in this taxonomy, species-level detail is given for Marattia s.str. and the segregated genera Eupodium and Ptisana. New combinations are made in Eupodium and Ptisana. Considerable monographic work still remains to be done, and is of particular importance given the threatened status of many presently poorly understood species in this family.