1. Organismal and Evolutionary Biology Research Programme and Botany Unit of the Finnish Museum of Natural History, P.O. Box 7, FI-00014 University of Helsinki, Finland;
2. Department of Forest Ecology & Genetics, Forest Research Centre, INIA-CIFOR, Carretera de la Coruña km 7.5, 28040 Madrid, Spain;
3. Herbarium, Biodiversity Unit, FI-20014 University of Turku, Finland;
4. Nees Institute for Plant Biodiversity, University of Bonn, Meckenheimer Allee 170, D-53115 Bonn, Germany;
5. Department of Natural Sciences, National Museum Wales, Cathays Park, Cardiff, CF10 3NP, U.K.;
6. Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA Leiden, The Netherlands;
7. Department of Botany, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden