Abstract Detail

Systematics Section / ASPT

Funk, Vicki A [5], Bayer, R.J. [6], Keeley, S. [7], Chan, R. [7], Watson, L. [3], Gemeinholzer, B. [8], Schilling, E. [4], Panero, J.L. [2], Baldwin, B.G. [1], Garcia-Jacas, N. [9], Susanna, A. [9], Jansen, R.K. [2].

Using a supertree to understand the diversity and distribution of the Compositae.

One of every 10 flowering plant species is in the family Compositae. The family is monophyletic and the sub-familial classification and ideas about major patterns of evolution and diversification within the family remained largely unchanged from Bentham through Cronquist. In this study the results of recent broad-scale molecular studies of the tribes, both published and unpublished, were used to produce a supertree formed by linking the respective trees together. The distribution of the terminal taxa produced a biogeographic pattern. Basal lineages were mostly southern South American followed by a subsequent radiation in Africa that gave rise to most of the tribes we know today. The African radiation was followed by the radiation of individual clades in Asia, Eurasia, Australia, etc. Finally, there was a North American origin and diversification of the Heliantheae s. l. that involved repeated incursions into Mexico and South America. The South American radiation followed by the African explosion might suggest a Gondwanan origin for the family, but the few data that exist from pollen records and geology indicate a more recent origin for the family. The existence of the monotypic genus Hecastocleis inserts a North American taxon in between the South American and African radiations which might indicate long distance dispersal, or a North American or even an Asian presence. The sister-group to the western hemisphere clade Heliantheae s. l. is the small tribe Athroismeae, from eastern tropical Africa, leaving an unknown area, possibly Asia, between Africa and western North America. This global picture of the Compositae provides a framework for studies in morphology and clearly indicates the need for future molecular and morphological studies.

1 - University of California, Berkeley, Integrative Biology, University and Jepson Herbaria, 1001 Valley Life Sciences Building, Berkeley, California, 94720-2465, USA
2 - University of Texas at Austin, Section of Integrative Biology, 1 Universiy Station, #A6700, Austin, Texas, 78712, USA
3 - Miami University, Department of Botany, 316 Pearson Hall, Oxford, Ohio, 45056, USA
4 - University of Tennessee, Department of Botany, 437 Hesler Biology, Knoxville, Tennessee, 37996, USA
5 - Smithsonian Institution, US National Herbarium, MRC166, Washington, DC, 20013-7012, USA
6 - CSIRO, Australian National Herbarium, P.O. Box 4008 1600, Canberra, Australian Capital Territory, 2600 2601, Australia
7 - University of Hawaii, Department of Botany, Manoa, Oahu, Hawaii, 96822-2279, USA
8 - Institute of Plant Genetics & Crop Plant Research, Corrensstrasse 3, Gatersleben, D-06466, Germany
9 - Botanic Institute of Barcelona (CSIC), Laboratory of Biosystematics and Molecular Systematics, Pg. del Migdia, s.n., Barcelona, E-08038, Spain

Keywords:
Compositae
Asteraceae
Arctoteae
phylogeny
molecular systematics
Unrooted networks
supertree
biogeography.

Presentation Type: Paper
Session: 3-4
Location: Cottonwood B (Snowbird Center)
Date: Monday, August 2nd, 2004
Time: 8:45 AM
Abstract ID:550