1. Department of Biology; University of Florida; Gainesville, Florida 32611 U.S.A
2. L. H. Bailey Hortorium, Department of Plant Biology; Cornell University; Ithaca, New York 14853 U.S.A
3. Florida Museum of Natural History; University of Florida; Gainesville, Florida 32611 U.S.A
4. School of Biological and Chemical Sciences; Queen Mary, University of London; London E1 4NS U.K