Phylogenetic and Morphological Analyses Support the Resurrection of Dendroconche and the Recognition of Two New Genera in Polypodiaceae Subfamily Microsoroideae

Despite being the focus of considerable taxonomic (Bosman 1991; Nooteboom 1997; Zhang et al. 2018) and phylogenetic study (Schneider et al. 2006; Kreier et al. 2008; Testo and Sundue 2014, 2016; Sundue et al. 2015; Nitta et al. 2018; Zhang et al. 2019), generic circumscription in the microsoroid ferns (Polypodiaceae subfamily Microsoroideae sensu PPG I, 2016) has remained uncertain. Taxonomic resolution of the subfamily has been hindered in large part by the morphological heterogeneity and non-monophyly of Microsorum, as demonstrated by Bosman (1991) in her monograph of the genus and later by a series of phylogenetic studies (Schneider et al. 2004, 2006; Kreier et al. 2008; Testo and Sundue 2014, 2016; Nitta et al. 2018). In each of these studies, several species of Microsorum and the allied genus Colysis were found not to be closely related to Microsorum s. s. but instead were resolved in a grade allied to the Old-World ant-fern genus Lecanopteris. Although this finding was discussed by the authors of each of these studies, they did not attempt to resolve the outstanding taxonomic issues, as this would require either naming several new genera or placing these taxa in a broadly construed and morphologically incoherent Lecanopteris. Here, we generate a molecular phylogeny and examine the morphology of this group to circumscribe monophyletic and morphologically cohesive clades and provide the appropriate taxonomic innovations to resolve the long-standing taxonomic problems associated with these species