1. Department of Fish and Wildlife Resources, College of Natural Resources, University of Idaho, Moscow, ID 83844, USA
2. Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK
3. Departamento de Botânica, Universidade Federal do Rio Grande do Sul, Caixa Postal 15100, 91501-970 Porto Alegre, RS, Brasil
4. Institute for Systematic Botany, University of Zurich, Zollikerstrasse 107, 8008 Zurich, Switzerland