1. Division of Plant and Soil Sciences; West Virginia University; 100 Research Way G153 South Agricultural Sciences Building Morgantown 26506 WV USA
2. Department of Biological and Environmental Sciences; University of Gothenburg; Box 461 SE-405 30 Göteborg Sweden
3. Gothenburg Botanical Garden; Carl Skottsbergs gata 22A; SE-41319 Göteborg Sweden
4. Plant Systematics and Biodiversity Laboratory; University of Geneva and Conservatoire et Jardin botaniques de la ville de Genève; C.P. 60 1292 Chambésy Switzerland