1. Department of Organismic and Evolutionary Biology Harvard University Cambridge MA 02138 USA
2. Biodiversity and Bioresources Agriculture and Agri‐Food Canada 960 Carling Avenue Ottawa ON K1A 0C6 Canada
3. Food Quality Laboratory, Agricultural Research Service US Department of Agriculture Beltsville MD 20705 USA
4. School of Environmental and Forest Sciences University of Washington Seattle WA 98195 USA
5. General Botany and Plant Systematics, Institute of Botany and Landscape Ecology Ernst Moritz Arndt University Greifswald 17487 Greifswald Germany
6. Staatliches Museum für Naturkunde Abteilung Biowissenschaften D‐76133 Karlsruhe Germany