1. Department of Systematics and Evolutionary Botany, University of Zurich, Zurich 8048, Switzerland
2. Red de Ecología Funcional, Instituto de Ecología, A. C. Carretera antigua a Coatepec No. 351, El Haya, Xalapa, Veracruz 91073, México
3. Instituto de Botánica del Nordeste, UNNE-CONICET, 3400, Corrientes, Argentina
4. Department of Biology, University of Florida, Gainesville, FL 3261, USA
5. Department of Ecology, Evolution, and Environmental Biology, Columbia University, New York, NY 10027, USA New York Botanical Garden, New York, NY 10458, USA
6. Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
7. Department of Biology, Colgate University, Hamilton, NY 13346, USA