Download Origin and diversification of the austral genus Dracophyllum

Dragons in the mist: origin and
diversification of the austral genus
Dracophyllum (Ericaceae)
Steven J. Wagstaff1, Murray I. Dawson1, S. Venter2, Jérôme Munzinger3, Darren
M. Crayn4, Dorothy A. Steane5, Kristina L. Lemson6
Dracophyllum subgenus
Dracophyllum
D. fitzgeraldii
About 21 species are placed in
subgenus Dracophyllum; 7 of these
are found only in New Zealand, 8 are
confined to New Caledonia, 4 to
Australia, 1 to Tasmania, and 1 to
Lord Howe Island.
D. oceanicum
D. ouaiemense
D. verticillatum
D. mackeeanum
D. fiordense
Dracophyllum subgenus
Oreothamnus
Some 29 species are recognized
in subgenus Oreothamnus. With
the exception of D. minimum
found in Tasmania, they are
endemic to New Zealand.
D. longifolium
D. pronum
D. muscoides
D. minimum
Dracophyllum subgenus
Cordophyllum
Subgenus Cordophyllum includes
a single species, Dracophyllum
involucratum, which is restricted
to New Caledonia
D. involucratum
Richea
R. continentis
R. sprengelioides
11 species are recognized that are placed
in two sections. These are restricted to
Tasmania and southeastern Australia
R. scoparia
R. pandanifolia
R. victoriana
Sphenotoma
Includes about 8 species that are
restricted to Southwestern Australia
S. gracile
S. dracophylloides
S. capitata
Distribution of
Dracophyllum
and its relatives
Sphenotoma
and Richea
Predictions
•
•
•
•
Differences in taxonomic interpretation
Fragmentation and extinction
Long-distance dispersal with prevailing westerly winds
Recent founder speciation on oceanic islands rather
than greater age
New Caledonia
Australia
New Zealand
Australia
Jordan, G.J.; Bannister, J.M.; Mildenhall, D.C.; Zetter, R.; Lee, D.E. 2010. Fossil Ericaceae from New Zealand: Deconstructing the use of
fossil evidence in historical biogeography. American Journal of Botany 97: 59-70.
Furness, Caroll A. 2009. Pollen evolution and development in Ericaceae, with particular reference to pseudomonads and variable pollen Sterility
in Styphelioideae. International Journal of Plant Sciences 170: 476-495.
Divergence estimates given as million years ago (Ma).
Node
No. of
bootstrap
trees in r8s
profile
Maximum likelihood
Bayesian
Stem age for Tribe Richeeae
100
33.4 ± 3.5 (12.2–44.1)
35.0 (26.9–36.3)
Crown radiation in Tribe Richeeae
100
20.6 ± 2.9 (7.2–35.9)
27.0 (8.7–21.4)
Stem age of New Caledonian
radiation
47
5.6 ± 0.7 (3.9–7.0)
8.7 (4.7–13.0)
Crown age of New Caledonian
radiation
92
3.5 ± 1.1 (0.7–6.5)
6.1 (3.0–10.0)
Stem age of New Zealand radiation
95
6.2 ± 1.0 (2.6–8.8)
11.2 (7.1–15.9)
Crown age of New Zealand
radiation
100
3.0 ± 1.2 (1.1–7.7)
9.7 (5.7–14.1)
Stem age of Dracophyllum subg.
Oreothamnus in New Zealand
100
1.1 ± 1.1 (0.0-–7.1)
3.7 (1.5–7.3)
23.8 Ma
Fixed age
90 Ma
“During the late
Miocene-Pliocene at
least 15 families and a
minimum of 36 genera
were lost from the New
Zealand flora”
Lee, D.E.; Lee, W.G.; Mortimer, N. 2001. Where and why have all the flowers gone? Depletion and turnover in the New Zealand Cenozoic angiosperm
flora in relation to palaeogeography and climate. Australian Journal of Botany 49: 341-356.
http://www.gns.cri.nz/Home/Learning/Science-Topics/Fossils/NZ-fossils/Fossil-Plants
Nathan, R.; Schurr, F.M.; Spiegel, O.; Steinitz, O.; Trakhtenbrot, A.; Tsoar, A. 2008. Mechanisms of long-distance seed dispersal. Trends in
Ecology & Evolution 23: 638-647.
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. NASA image
by Jeff Schmaltz
Barraclough, T.G.; Nee, S. 2001. Phylogenetics and speciation. Trends in Ecology & Evolution 16: 391-399.
Summary
• Sphenotoma monophyletic; Dracophyllum
paraphyletic, and Richea polyphyletic.
• Species richness greatest in New Zealand and New
Caledonia, but phylogenetic diversity greatest in
Australia
• Oligocene-early Miocene fossils in New Zealand may
represent extinct lineages distantly related to extant
species of Dracophyllum
• Australian species of Dracophyllum remnants of older
widely distributed lineages
• In contrast the extant species in New Zealand and
New Caledonia species radiated more recently
following long-distance dispersal
Steven J. Wagstaff1, Murray I. Dawson1, Stephanus Venter2, Jérôme Munzinger3, Darren M. Crayn4, Dorothy A.
Steane5, Kristina L. Lemson6
1Allan
Herbarium, Landcare Research, PO Box 40, Lincoln 7640, New Zealand.
and Environmental Consultant, PO Box 63, Trinity Beach, Queensland, 4879, Queensland, Australia.
3IRD, UMR AMAP, d’Ecologie Végétale Appliquées, Herbarium NOU, F-98848 New Caledonia.
4Australian Tropical Herbarium, James Cook University Cairns Campus, PO Box 6811, Cairns 4870, 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.
2Botanical
Wagstaff, S.J.; Dawson, M.I.; Venter, S.; Munzinger, J.; Crayn, D.M.; Steane, D.A.; Lemson, K.L. 2010. Origin, diversification, and classification of the
Australasian Genus Dracophyllum (Richeeae, Ericaceae). Annals of the Missouri Botanical Garden 97: 235-258.
http://www.bioone.org/doi/abs/10.3417/2008130
Acknowledgments
This research was supported in part by a National Geographic Society’s
Committee for Research and Exploration grant 7774–05 and the New
Zealand Foundation for Research, Science and Technology through the
Defining New Zealand’s Land Biota OBI. The authors thank many individuals
for their assistance with fieldwork, including those from Australia: Jayne Balmer
and Jaz Jaynes (Tasmania); Spiro Buhagiar, Ray Moore, and Michelle
Nissen (Queensland); Andrew Perkins, Muhammad Iqbal and Brendon
Neilly (New South Wales); Ian Hutton and Terry Wilson (Lord Howe Island);
and Michel Blanc, Daniel and Irène Létocart (New Caledonia). Mary Korver,
Peter de Lange and Phil Garnock-Jones of New Zealand collected specimens
of Dracophyllum from Tasmania, the Chatham, Three Kings and subantarctic
islands. Earlier drafts benefited greatly from the insightful comments of Greg
Jordan, Daphne Lee, Ilse Breitwieser, Thomas Buckley, Walt Judd, Kathy
Kron and Ulf Swensen.