Systematics Section / ASPT
Carlson, Sara , Donoghue, Michael J. .
Implications of a preliminary phylogenetic analysis of Dipsacaceae.
The Mediterranean-centered Dipsacaceae (Dipsacales) is characterized by an epicalyx, a novel structure that subtends the flower and forms the dispersal apparatus. Different epicalyx phenotypes are responsible for the many dispersal syndromes found in the group, which suggests that the epicalyx is a “key innovation” that spurred the adaptive radiation of the Dipsacaceae. Phylogenetic relationships within Dipsacaceae were inferred using sequence data from two chloroplast regions (the trnL intron and the trnS-G intergenic spacer) and the internal transcribed spacer (ITS) region of nuclear ribosomal DNA. Both genomes, as well as a combined data set, provide support for the Scabioseae, Knautieae, and Dipsaceae, as well as for the monophyly of most of the currently recognized genera. The large clade Lomelosia, which contains the most diversity in epicalyx morphology, may be paraphyletic. Our analyses indicate that Pterocephalodes hookeri, a species distributed in the Himalayas and mountains of Southwest China, may be sister to all remaining Dipsacaceae. The Dipsacaceae most likely originated in Asia and subsequently moved into Europe, possibly several times, and to Africa. Wing-like epicalyces and multiple, plumose calyx bristles appear to have evolved multiple times, suggesting selection for different modes of abiotic dispersal.
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1 - Yale University, Department Ecology & Evolutionary Biology, Po Box 208105, New Haven, Connecticut, 06520-8105, USA
2 - Yale University, Ecology & Evolutionary Biology and Peabody Museum of Natural History, PO Box 208106, New Haven, CT, 06520-8106, USA
Presentation Type: Oral Paper:Papers for Sections
Location: Lake Erie/Hilton
Date: Monday, July 9th, 2007
Time: 2:00 PM