@ARTICLE{TreeBASE2Ref18588, author = {Steven J. Wagstaff and M. I. Dawson and Stephanus Venter and J?r?me Munzinger and Darren M. Crayn and Dorothy A. Steane and Kristina L. Lemson}, title = {Origin, Diversification, and Classification of the Australasian Genus Dracophyllum (Richeeae, Ericaceae)}, year = {2010}, keywords = {}, doi = {10.3417/2008130}, url = {}, pmid = {}, journal = {Annals of the Missouri Botanical Garden}, volume = {97}, number = {2}, pages = {235--258}, abstract = {The genus Dracophyllum (Ericaceae) has a fragmented distribution in Australasia, but reaches the greatest level of species richness and morphological diversity in New Zealand. We investigated evolutionary processes that contribute to this disparity in species richness by comparing DNA sequences from members of Dracophyllum, its close relatives Richea and Sphenotoma (together constituting Tribe Richeeae), along with more distant relatives in the Ericaceae. We created complementary data sets for the chloroplast-encoded genes matK and rbcL. Both Bayesian and maximum likelihood analyses were conducted to assess the robustness of our phylogenetic inferences. The results were largely congruent and when analyzed in combination provided greater resolution. In our analyses, Tribe Richeeae formed a monophyletic group that diverged during the Eocene (at least 33.3 Ma) with a crown radiation during the early Miocene (at least 16.5 Ma) that resulted in two disjunct lineages. This date corresponds roughly to the onset of aridification in central Australia. The Western Australian genus Sphenotoma formed an isolated evolutionary lineage, while Dracophyllum and Richea together formed a second lineage restricted to Eastern Australia, Lord Howe Island, New Caledonia and New Zealand. The relationships of the Tasmanian endemic, Dracophyllum milliganii, remain an enigma. It was ambiguously placed in our analyses either emerging as sister to Sphenotoma or to the Dracophyllum/Richea clade. Richea was polyphyletic; we recovered two distinct lineages of Richea, traditionally recognized as R. sect. Cystanthe and R. sect. Dracophylloides; these were nested within Dracophyllum. Because Richea is polyphyletic, the status of this genus (and the respective infrageneric classifications of Dracophyllum and Richea) may be equivocal. The New Caledonian and New Zealand species of Dracophyllum dispersed from Australia; we document two independent episodes of long-distance dispersal in the late Miocene to early Pliocene. Low levels of sequence divergence suggest a rapid and recent species radiation in these two island archipelagos largely within the last 3--6 million years. This radiation accompanied Pliocene uplift of the New Zealand Southern Alps and episodes of glaciation during the Pleistocene. Key words:adaptive radiation, age, angiosperm, Australia, biogeography, classification, diversification, Dracophyllum, Ericaceae, island floras, Lord Howe Island, matK, molecular clock, molecular phylogenetics, molecular sequence data, molecular systematics, New Caledonia, New Zealand, phylogeny, plant evolution, rbcL, Richea, speciation, species richness, Sphenotoma, Tasmania.} }

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