Typification within the Polypodium virginianum complex (Polypodiaceae)

The validity and application of specific and varietal names in the Polypodium virginianum complex were investigated. Lectotypification of both P. virginianum L. and P. vulgare L. var. americanum Hooker is proposed, the former based on a plate in Morison and the latter on a collection by Percival at Kew. On morphological grounds, the types of both taxa appear to represent the tetraploid race in the complex. Hooker's variety therefore becomes a later synonym of the Linnaean species. Polypodium vinlandicum Löve and Löve was based on the type of Hooker's variety and thus is also synonymous with the tetraploid cytotype of P. virginianum. The name Polypodium "oreophilum" has sometimes been accepted as a legitimate name for some West Virginian plants in the complex. The combination, however, was never validly accomplished and so must be rejected. Furthermore, the use of the epithet for any member of this group is now prohibited by the South American P. oreophilum Maxon.