Phylogenetic relationships of species of Aciphylla (Apiaceae, subfamily Apioideae) and related genera using molecular, morphological, and combined data sets

Abstract

Evolutionary relationships of the Australasian genus Aciphylla were investigated using cladistic analyses of molecular (internal transcribed spacer regions 18S‐26S nuclear ribosomal DNA), morphological, and combined data sets. Molecular sequence data provide support for infrageneric groups within Aciphylla and show some agreement with species groups suggested by previous authors. Cladistic analysis of morphological characters traditionally used to describe species within Aciphvlla shows virtually no resolution of relationships, indicating considerable homoplasy within the data set. Analysis of combined molecular and morphological data reveals infrageneric groups that concur with those inferred by the molecular analysis, and shows increased resolution at the species level. The phylogeny resulting from the combined analysis provides a good framework for the interpretation of morphological characters in Aciphylla. Monophyly of Aciphylla is unresolved in all analyses. The Tas‐manian endemic Anisotome procumbens is unexpectedly placed in a clade with those New Zealand Aciphylla species (Aciphylla dobsonii and A. simplex) that have retained the most ancestral character states. Other Australasian Apioideae (Gingidia in part, Lignocarpa, and Scandia) are placed within the larger Aciphylla clade with those species that show an accumulation of derived character states for Aciphylla. Anisotome appears paraphyletic with respect to Aciphylla and the majority of Gingidia species, Taxonomic and biogeographical relationships within Aciphylla and related genera are discussed in the light of the inferred phylogeny.