Systematics/Phytogeography / Taxonomie/ Section
Sanchez, Adriana , Kron, Kathleen A. .
Phylogenetic relationships of Afrobrunnichia Hutch. & Dalziel (Polygonaceae) based on three chloroplast genes and ITS.
The subfamily Eriogonoideae (Sanchez and Kron 2008) comprises 31 genera of which 20 are part of the radiation of Eriogonum and allied genera in North America. The 11 remaining genera are all woody, poorly known and relatively inconspicuous due to their restricted distribution, number of species, and their habit. They are distributed in North, Central and South America, the Antilles and West Africa. Even though there are some widely recognized genera, such as Coccoloba, Antigonon and Brunnichia, in most cases the number of species is not known, even less their relationships. Brunnichia has long been recognized as a genus present in USA and West Africa, however it is often divided in two: Brunnichia corresponding only to the USA species and Afrobrunnichia to the African species. There has not been much work on the delimitation of these genera, and the veracity of this segregation has not been tested. In this study two accessions of Afrobrunnichia erecta, from Gabon and Ghana, are analyzed in addition to Brunnichia cirrhosa, Brunnichia ovata, two species of Antigonon, and several other taxa of Polygonaceae. Using a total of 4083 bp (22% parsimony informative characters) from three chloroplast genes (rbcL, matK and ndhF) and the internal transcribed spacer (ITS), a phylogeny was constructed. Maximum parsimony results strongly support Afrobrunnichia as sister to the remaining taxa of Eriogonoideae. Brunnichia and Antigonon are strongly supported as sister genera. Based on these results, Afrobrunnichia is a separate genus from Brunnichia, even though only one species was tested. There are several questions regarding other species of Afrobrunnichia (e.g. A. africana) and Brunnichia described, and regarding the biogeography of Eriogonoideae that emerge from these results.
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1 - Wake Forest University, Department of Biology, PO Box 7325, 226 Winston Hall, Winston-Salem, North Carolina, 27109-7325, USA
Presentation Type: Oral Paper:Papers for Sections
Location: Room 1/Woodward
Date: Monday, July 28th, 2008
Time: 8:15 AM