1. Center for Conservation and Sustainable Development Missouri Botanical Garden 4344 Shaw Boulevard St. Louis MO 63110 U.S.A.
2. Division of Biostatistics Washington University St. Louis MO 63110 U.S.A.
3. Center for Plant Conservation San Diego Zoo Global 15600 San Pasqual Valley Road Escondido CA 92027 U.S.A.
4. Department of Biological Sciences Chicago State University SCI 292, 9501 South King Drive Chicago IL 60628 U.S.A.
5. The Morton Arboretum 4100 Illinois Route 53 Lisle IL 60532–1293 U.S.A.
6. New England Wild Flower Society 180 Hemenway Road Framingham MA 01701 U.S.A.
7. Florida Department of Environmental Protection Florida Park Service 77200 Overseas Highway Islamorada FL 33036 U.S.A.
8. North Carolina Botanical Garden The University of North Carolina at Chapel Hill CB 3375, Chapel Hill NC 27599 U.S.A.
9. Fairchild Tropical Botanic Garden 10901 Old Cutler Road Miami FL 33156 U.S.A.
10. Research, Conservation, and Collections Desert Botanical Garden 1201 North Galvin Parkway Phoenix AZ 85008 U.S.A.
11. U.S. Geological Survey Western Ecological Research Center 1901 Spinnaker Drive Ventura CA 93001 U.S.A.
12. The Arboretum at Flagstaff 4001 S. Woody Mountain Road Flagstaff AZ 86005 U.S.A.
13. Division of Fish, Wildlife & Plant Conservation U.S. Department of Interior, Bureau of Land Management 1849 C Street NW (LSB‐204) Washington D.C. 20240 U.S.A.
14. U.S. Geological Survey, Great Lakes Science Center Lake Michigan Ecological Research Station 1574 N 300 E Chesterton IN 46304 U.S.A.
15. Bok Tower Gardens 1151 Tower Boulevard Lake Wales FL 33853 U.S.A.