AUTHORS’ PAGE PROOFS: NOT FOR CIRCULATION CSIRO PUBLISHING Australian Systematic Botany https://doi.org/10.1071/SB18015 A dated molecular perspective of eucalypt taxonomy, evolution and diversification Andrew H. Thornhill A,B,C,H, Michael D. Crisp D, Carsten Külheim D,E, Kristy E. Lam A, Leigh A. NelsonF, David K. YeatesF and Joseph T. Miller A,G ACentre for Australian National Biodiversity Research, National Research Collections, Black Mountain, CSIRO, Canberra, ACT 2601, Australia. BAustralian Tropical Herbarium, James Cook University, Cairns, Qld 4870, Australia. CUniversity and Jepson Herbaria, and Department of Integrative Biology, University of California, Berkeley, CA 94720-2465, USA. DDivision of Evolution and Ecology, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia. ESchool of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931, USA. FAustralian National Insect Collection and Taxonomic Research and Information Network, National Research Collections, Black Mountain, CSIRO, ACT 2601, Australia. GOffice of International Science and Engineering, National Science Foundation, Alexandria, VA 22314, USA. HCorresponding author. Email:
[email protected] Abstract. The eucalypts, which include Eucalyptus, Angophora and Corymbia, are native to Australia and Malesia and include over 800 named species in a mixture of diverse and depauperate lineages. We assessed the fit of the eucalypt taxonomic classification to a phylogeny of 711 species scored for DNA sequences of plastid matK and psbA–trnH, as well as nuclear internal transcribed spacer and external transcribed spacer. Two broadly similar topologies emerge from both 5 maximum likelihood and Bayesian analyses, showing Angophora nested within Corymbia or Angophora, sister to Corymbia. The position of certain species-poor groups on long branches fluctuated relative to the three major Eucalyptus subgenera, and positions of several closely related species within those subgenera were unstable and lacked statistical support.