1. Department of Organismic and Evolutionary Biology, Harvard University Herbaria, 22 Divinity Avenue, Cambridge, MA 02138, USA.
2. Department of Plant Biology, Southern Illinois University, 1125 Lincoln Drive, Carbondale, IL 62901–6509, USA.
3. Department of Botany, Smithsonian Institution, NMNH MRC-166, Washington, DC 20013–7012, USA.
4. Department of Botany, University of Wisconsin, 430 LincolnDrive, Madison, WI53706, USA.