Affiliation: | 1. Department of Botany, Oklahoma State University 301 Physical Science, Stillwater, OK 74078, USA 2. Department of Botany, National Museum of Natural History, MRC 166, Smithsonian Institution, Washington, DC 20013-7012, USA 3. Department of Plant Biology, North Carolina State University, 4209 Gardner Hall, Campus Box 7612, Raleigh, NC 27695, USA |