Phylogeny and generic taxonomy of the New Zealand Pteridaceae ferns from chloroplast rbcL DNA sequences

Abstract

Previous molecular phylogenetic studies of the species-rich Pteridaceae fern family have revealed that many of its constituent genera are not monophyletic. Within this context, we generated rbcL chloroplast DNA sequences for the 17 Pteridaceae species indigenous to New Zealand to assess how they are related to the type species of their genus. Of the five genera presently recognised in New Zealand, no taxonomic change is needed for the species of Anogramma, or, probably, of Cheilanthes and Pellaea. In contrast, most species presently attributed to Pteris, including those in New Zealand, probably do not belong there. The status of Adiantum remains unclear, although the New Zealand species are not especially closely related to the type species. The Adiantum species in New Zealand belong to a wide-ranging, principally southern hemisphere, clade that appears to be pivotal to resolving the relationships of Adiantum, although it has been little sampled. The closest relatives of the New Zealand species are in Australia and South America for Cheilanthes, Australia and South-east Asia for Pellaea, and the south-western Pacific for both of the Pteris lineages in New Zealand, whereas Anogramma leptophylla (L.) Link is subcosmopolitan.