1. Laboratory of Plant Systematics, Institute of Botany and Microbiology,; K.U. Leuven, Kasteelpark Arenberg 31, P.O. Box 2437, Leuven, 3001 Belgium,
2. Netherlands Centre for Biodiversity Naturalis (section NHN),; Leiden University Branch, P.O. Box 9514, RA Leiden, The 2300 Netherlands
3. Present address School of Biological Sciences, Seoul National University,; Seoul 151-747, Korea;,