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Dragons in the mist: origin and diversification of the austral genus Dracophyllum (Ericaceae )

Dragons in the mist: origin and diversification of the austral genus Dracophyllum (Ericaceae ). Steven J. Wagstaff, Murray I. Dawson, Stephanus Venter, Jérôme Munzinger, Darren M. Crayn, Dorothy A. Steane, Kristina L. Lemson.

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Dragons in the mist: origin and diversification of the austral genus Dracophyllum (Ericaceae )

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  1. Dragons in the mist: origin and diversification of the austral genus Dracophyllum (Ericaceae) Steven J. Wagstaff, Murray I. Dawson, Stephanus Venter, Jérôme Munzinger, Darren M. Crayn, Dorothy A. Steane, Kristina L. Lemson

  2. “I am inclined to look in the southern, as in the northern hemisphere, to a former and warmer period, before the commencement of the glacial period, when the Antarctic lands, now covered with ice, supported a highly peculiar and isolated flora. I suspect that before this flora was exterminated by the glacial epoch, a few forms were widely dispersed to various points of the southern hemisphere by occasional means of transport, and by the aid, as halting places, of existing and now sunken islands, and perhaps at the commencement of the glacial period, by icebergs. By these means, as I believe, the southern shores of America, Australia, and New Zealand have become slightly tinted by the same peculiar forms of vegetable life.”– Darwin 1859.

  3. “the relationships are agreeable to the hypothesis of all being members of a once more extensive flora, which has been broken up by geological and climatic causes”.– Hooker 1853.

  4. Distribution of Dracophyllum and its relatives Richea and Sphenotoma

  5. Dracophyllum subgenus Dracophyllum About 21 species are placed in subgenus Dracophyllum; 7 are confined to New Zealand, 8 to New Caledonia, 4 to Australia, 1 to Tasmania, and 1 to Lord Howe Island. D. fitzgeraldii D. oceanicum D. mackeeanum D. ouaiemense D. verticillatum D. fiordense

  6. Dracophyllum subgenus Oreothamnus Some 29 species are recognized in subgenus Oreothamnus. With the exception D. minimum found in Tasmania, they are endemic to New Zealand. D. longifolium D. pronum D. muscoides D. minimum

  7. Dracophyllum subgenus Cordophyllum Subgenus Cordophyllum includes a single species, Dracophyllum involucratum, restricted to New Caledonia. D. involucratum

  8. Richea 11 species are recognized placed in two sections; R. sect. Cystanthe & R. sect. Dracophylloides. Richea is restricted to Tasmania and southeastern Australia. R. continentis R. sprengelioides R. scoparia R. victoriana R. pandanifolia R. pandanifolia

  9. Sphenotoma Includes about 8 species restricted to southwestern Australia. S. gracile S. undescribed sp. S. undescribed sp. S. dracophylloides S. capitata

  10. Research questions • Is Dracophyllum monophyletic? How is it related to Richea and Sphenotoma? • Where did these lineages originate, and when did they diverge? • What are the underlying reasons for differences in species richness between continental Australia, Tasmania, Lord Howe Island, New Caledonia and New Zealand?

  11. Enkianthus is one of the oldest members of the Ericaceae. Remarkably well-preserved fossilized flowers are reported from North American deposits dating from the late Cretaceous some 90 million years ago, and these exhibit characteristics associated with specialized insect pollination. Enkianthus subsessilis Rhododendron macrosepalum

  12. Satellite image of cyclone Larry as it was bearing down on the coast of Queensland. The storm sustained wind speeds of 185 km/hr before it came ashore. Catastrophic storms such as this may play an important role in plant dispersal. NASA image by Jeff Schmaltz

  13. Summary • Tribe Richeeae (Dracophyllum, Richea, Sphenotoma) is monophyletic • Sections & subgenera • New Zealand Dracophyllum subg. Oreothamnus is monophyletic • Tasmanian D. minimum appears misplaced • D. strictum is sister to D. subg. Oreothamnus • D. subg. Dracophylloides is polyphyletic • D. subg. Cordophyllum is nested among New Caledonian spp. of D. subg. Dracophylloides • The two Richea clades correspond with R. sect. Cystanthe & R. sect. Dracophylloides • Genera • Dracophyllum is paraphyletic • Richea is polyphyletic • Sphenotoma is monophyletic

  14. Summary – ctd. • Biogeography • While most of the morphological species diversity is found in New Zealand and New Caledonia, the phylogenetic diversity is greatest in Australia • Australian species of Dracophyllum are remnants of older lineages; their present distributions are fragmented and disjunct • In contrast, New Zealand (esp. subg. Oreothamnus) and New Caledonian species have recently radiated following long-distance dispersal from Australia • Evolution in the group was spurred by geological and climatic changes during the late Tertiary.

  15. Acknowledgments Numerous individuals graciously provided assistance and without their help this project would not have been possible. Jayne Balmer, Department of Primary Industries, Water and Environment, Hobart, Tasmania; Michel Blanc, Direction Des Ressources Naturelles, Providence Sud Nouvelle-Caledonie; Michelle Nissen, Coordinator, Scientific & Educational Purpose Permits, Northern Region – QPWS; Brendon Neilly, Senior Project Officer, Wildlife Licensing, Department of Environment and Conservation; Muhammad Iqbal, Wildlife Trade Assessments, the Australian CITES Scientific Authority; Terry Wilson, World Heritage Officer, Lord Howe Island Board helped with collection permit applications. Jaz Jaynes, Irene and Daniel Letocart, Andrew Perkins, and Ian Hutton shared their good humor and remarkable botanical knowledge. Spiro Buhagiar and Ray Moore provided access to the summit of Bellenden Kerr, which would have been virtually impossible in the aftermath of Cyclone Larry. Peter de Lange and Phil Garnock-Jones collected specimens of Dracophyllum from the Chatham, Three Kings and the Subantarctic Islands. This project was funded by the New Zealand Foundation for Research, Science and Technology and the National Geographic Society.

  16. Steven J. Wagstaff1, Murray I. Dawson1, S. Venter2, Jérôme Munzinger3, Darren M. Crayn4, Dorothy A. Steane5, Kristina L. Lemson6 1Allan Herbarium, Landcare Research, PO Box 40, Lincoln 7640, New Zealand 2Botanical and Environmental Consultant, 68 Kenneally Road, Mareeba 4880, Queensland, Australia 3Laboratoire de Botanique et d'Ecologie Végétale Appliquées, IRD Institut de recherche pour le dévelopement, Centre de Nouméa, BP A5 Nouméa 98848, New Caledonia 4Royal Botanic Gardens, National Herbarium of New South Wales, Mrs Macquaries Road, Sydney, New South Wales 2000, Australia 5School of Plant Science, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia 6Centre for Ecosystem Management & School of Natural Sciences, Edith Cowan University, 100 Joondalup Drive, Joondalup, Western Australia 6027, Australia

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