1. Department of Life Sciences, University of Trieste, via Giorgieri 10, 34127 Trieste, Italy
2. Institute of Environmental Sciences CML, Leiden University, Einsteinweg 2, 2333 CC, Leiden, The Netherlands
3. Department of Natural History, University Museum, University of Bergen, Allegt. 41, 7800, N-5020 Bergen, Norway
4. Department of Plant Taxonomy and Nature Conservation, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland
5. Institute of Botany, Academy of Science of Czech Republic, Zámek 1, CZ-25243 Průhonice, Czech Republic
6. Department of Botany, Faculty of Natural Sciences, Charles University, Benátská 2, CZ-12801 Praha, Czech Republic