Systematics Section / ASPT
Robart, Bruce , Gladys, Carl , McCafferty, Katie , Koch, Brad , Tran, Christine .
Evolutionary History and Divergence of Pedicularis (Scrophulariaceae) in North America..
Pedicularis is a common element of tundra, alpine, and subalpine floras in Asia and North America. Its incursion and diversification into North America from Asia is thought to have occurred through Beringia and/or the circumpolar province. While the pollination ecology of most North American and some Asian species has been well documented, no phylogeny has been reconstructed on which to relate floral adaptations. In order to place ecological adaptations and biogeography of North American species into evolutionary context, relationships were reconstructed with parsimony analysis of DNA sequences among nuclear ITS and chloroplast matK regions. Analysis of ITS resulted in four equally parsimonious trees (CI=0.7773, HI=0.2227) with three well resolved clades. One clade consists of all unbeaked species primarily distributed throughout western coastal mountain ranges. Another clade is composed of two subclades that include species with 2-3 calyx tips and species with rostrate corollas, respectively. The third clade consists of species predominantly of arctic distribution. Biogeographical patterns suggest two migration routes: one occurred from eastern arctic south and westward to the Rocky Mountains and the second occurred from Asia eastward through Beringia to arctic and subarctic North America. Although the matK tree was only partially congruent with the ITS tree, it does support P. bracteosa and P. capitata as the parental species of the putative hybrid, P. rainierensis.
1 - University of Pittsburgh at Johnstown, Department of Biology, E&S 116, Johnstown, Pennsylvania, 15904
Presentation Type: Poster
Location: Special Event Center (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 12:30 PM