1. Swedish University of Agricultural Sciences and Linnean Center of Plant Biology Uppsala BioCenter Uppsala SE‐75007 Sweden
2. Biological and Environmental Sciences School of Natural Sciences University of Stirling Stirling FK9 4LA UK
3. Laboratory of Evolutionary Botany Institute of Biology University of Neuchâtel Neuchâtel CH‐2000 Switzerland
4. School of Biology University of St Andrews St Andrews Fife, KY16 9TH UK