1. Department of Biology, Colorado State University, Fort Collins, Colorado 80523‐1878 USA
2. Department of Botany and Laboratories of Analytical Biology, Smithsonian Institution Museum Support Center, Suitland, Maryland 20746 USA
3. CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Campus Agrário de Vairão, 4485‐661 Vairão, Portugal
4. Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013‐7012 USA