1. Department of Plant Systematics, University of Bayreuth, D-95440 Bayreuth, Germany.
2. Evolutionary Biology and Ecology, Free University of Brussels/Université Libre de Bruxelles, avenue FD Roosevelt 50 CP 160/12, B-1050 Brussels, Belgium.
3. Institute of Systematic Botany, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland.