A taxonomic revision of the genus Grammitis Swartz (Grammitidaceae: Filicales) in New Guinea

Abstract

A taxonomic revision of the fern genus Grammitis Swartz (Grammitidaceae) in New Guinea has been made, in which 64 species belonging to 14 species groups are recognised. Forty-five species are endemic to New Guinea and 21 species are hitherto undescribed. Problems in generic classification are outlined and the morphological characters used in the delimitation and description of the species and species groups are discussed. A bracket key to species and a multi-access key to species groups are provided for identification. For each species there is a complete citation of nomenclature, an illustration of a complete plant together with details of part of a frond, a full description and a summary of habitat, vegetation type and altitude. All of the specimens examined are cited, giving locality, altitude, date, collector and number, and herbaria in which the collection has been seen. The distribution of each species is mapped within New Guinea and the distribution of non-endemic species beyond New Guinea is also shown. Maps of each non-endemic species group are given which outline the distribution of all members. Following the taxonomic account the geographical affinities and distribution of the species and species groups both within and beyond New Guinea are investigated. The presence of five distribution patterns for the non-endemic species and species groups is established and the existence of a central core of distribution within New Guinea is outlined. Some aspects of ecological distribution in New Guinea are considered and the wider ecological tolerance of some non-endemic species, compared with endemic species, is suggested. Finally, the means by which the speciation of Grammitis in New Guinea may have been promoted is discussed.