1. Department of Biology, University of Puerto Rico-Río Piedras , San Juan, PR 00931 , USA
2. Department of Ecology and Evolutionary Biology, University of Tennessee , Knoxville, TN 37996 , USA
3. North American Orchid Conservation Center, Smithsonian Institution , Edgewater, MD 21037 , USA
4. Center for Conservation & Sustainability, Smithsonian Conservation Biology Institute , PO Box 37012, MRC 705, Washington, DC 20013-7012 , USA
5. BASF Corporation , 59729 200th St., Nevada, IA 50201 , USA