PLEOPELTIS (POLYPODIACEAE), A REDIFINITION OF THE GENUS AND NOMENCLATURAL NOVELTIES

Recent evidence from morphological, cytological, and gene sequencing studies has provided several additional evidence that the genus Pleopeltis (Polypodiaceae) requires redefinition to include other polypod genera and species with peltate scales on the leaf blades. Groups to be included are Polypodium subg. Marginaria (species treated in the group of P. polypodioides (L.) Watt by Moran), and also including the P. squamatum and P. plebeium groups, Dicranoglossum, Microphlebodium, Neurodium, and Pseudocolysis. In this paper, we review all species of Polypodiaceae that we believe belong to Pleopeltis and make 35 species combinations, one varietal combination, one new status, and five hybrid combinations. In addition, three new names are necessary for species prevented from transfer because to do so results in homonymy. As redefined, Pleopeltis comprises ca. 90 species, mainly in the New World, but with two species and one hybrid in Africa, India, and Sri Lanka; it excludes Lepisorus in Asia and Africa, as well as many other especially simple-bladed Old World species once placed in Pleopeltis but now included in other Paleotropical genera, e.g., Lemmaphyllum, Leptochilus, and Selliguea. We provide a key to separate the American polypod genera, and address biogeographical data that derive from this new circumscription. In two appendices, we list previously accepted taxa of Pleopeltis for which combinations are already available, as well as salient synonymy.