1. Institut für Botanik der TU Darmstadt, Schnittspahnstrasse 4, D-64287 Darmstadt, Germany
2. Western Regional Research Center, USDA-ARS, 800 Buchanan Street, Albany, CA 94710, U.S.A
3. Department of Systematic and Evolutionary Botany, Institute of Botany, University of Vienna, Rennweg 14, A-1030 Wien, Austria