Gordon Burleigh
Gordon Burleigh
Gordon is studying phylogenetics of Silene and the Caryophyllaceae and molecular evolution of nrITS and the trnL intron.
Silene, with approximately 700 taxa, is the largest genus in the Caryophyllaceae. It contains species with very diverse floral morphologies, pollination syndromes, and mating systems. Roughly 50 Silene taxa are endemic to North America, with nine diverse taxa found exclusively east of the Rocky Mountains. We used both nuclear ribosomal ITS and chloroplast trnL intron sequences to create a phylogeny of the Eastern North American Silene taxa in order to determine if the Eastern North American taxa are monophyletic and if the hummingbird pollinated taxa are monophyletic.
This is an ITS maximum likelihood phylogeny including eight of the nine Eastern North American Silene taxa, with two Western North American Silene, and several outgroup Silene taxa. The numbers on the branches are bootstrap values. The parentheses contain the taxa's sectional classification according to Chowdhuri's (1957) definitions. The Eastern North American taxa only are colored according to their flower color. The taxa in red have larger, red flowers and are hummingbird pollinated. The taxa in pink have smaller, pink flowers, and the taxa in black have white, fringed flowers.
The Eastern North American taxa form two distinct clades. The position of the Western North American taxa S. petersonii as the sister taxon to one of the Eastern North American clades indicates that the Eastern North American taxa are not monophyletic. All European and circumpolar Silene taxa are basal to the North American taxa, but these branches are not strongly supported. The Eastern North American taxa do not group by pollination syndrome or floral morphology, and the hummingbird taxa are not monophyletic. Also, the ITS sequences of Chowdhuri's (1957) section Occidentales are polyphyletic.