1. Arne A. Anderberg (author for correspondence), Department of Phanerogamic Botany, Swedish Museum of Natural History, P.O. Box 50007, SE-10405 Stockholm, Sweden; e-mail: arne.anderberg@nrm.se
2. Ulrika Manns, Department of Botany, University of Stockholm, SE-10691 Stockholm, Sweden.
3. Mari Källersjö, Laboratory for Molecular Systematics, Swedish Museum of Natural History, P.O. Box 50007, SE-104 05 Stockholm, Sweden.