1. 3Department of Botany, Box 355325, University of Washington, Seattle, Washington 98195 USA;
2. 4Department of Biology, Life Sciences Consortium, and Institute of Molecular Evolutionary Genetics, Pennsylvania State University, 208 Mueller Lab, University Park, Pennsylvania 16802 USA;
3. 5Department of Evolution, Ecology, and Organismal Biology, Ohio State University, 1735 Neil Avenue, Columbus, Ohio 43210 USA;
4. 6Department of Biology, Trinity University, 715 Stadium Drive, San Antonio, Texas 78212 USA; and
5. 7Department of Botany and Microbiology, University of Oklahoma, 770 Van Vleet Oval, Norman, Oklahoma 73019–6131 USA