1. Institut für Organische Chemie der Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany, Department of Chemistry, University of Malaya, 59100 Kuala Lumpur, Malaysia, Swiss Tropical Institute, Socinstrasse 57, CH-4002 Basel, Switzerland, and Department Biology I, Section: Biodiversity Research, Systematic Botany, Ludwig-Maximilians University Munich, Menzinger Strasse 67, D-80638 München, Germany