Rytidosperma vickeryae — a new danthonioid grass from Kosciuszko (New South Wales, Australia): Morphology, phylogeny and biogeography

Abstract

Rytidosperma vickeryae, a new species of danthonioid grass, is described, and detailed information on the morphology, anatomy, cytology and embryology of the species is provided. The phylogenetic relationships among the Australasian species of Rytidosperma s.s. are analysed, by parsimony-based methods. The new species is shown to be the sister species of R. thomsonii from New Zealand. The phytogeographical implications of this are analysed, by area-optimisation methods as well as methods which search for area relationships. This suggests that the Australasian species of Rytidosperma radiated from an ancestral area in Tasmania, followed by dispersal to New Zealand, and repeated dispersal northwards to Kosciuszko and New Guinea. R. vickeryae appears to have originated as the result of a dispersal event from New Zealand to Kosciuszko.