The Polypodiaceae is one of the largest families of homosporous ferns and in the New World is represented by the single tribe Polypodieae. About 90% of the species in the tribe occur in the neotropics where they are a conspicuous component of the epiphytic flora. Despite this concentration of species in the tropics, biosystematic studies within the tribe have focused only on the temperate zone species in the genus Polypodium. Graduate student Elisabeth Andrews, under the direction of faculty advisor Christopher Haufler, will apply analytical techniques that have proven successful in studies of Polypodium to a group of closely related tropical species. Morphological and molecular data will be combined in distinguishing species and in resolving phylogenetic or genealogical relationships within the Pleopeltis complex, a group of 15 simple-leaved species. Fieldwork in Jamaica and Costa Rica will provide plant material for cultivation, for chromosomal, isozymic (protein), and chloroplast DNA analyses. The anticipated research will complete the first biosystematic study of a group of epiphytic ferns, which integrates molecular and morphological data, and as such it may serve as a foundation for future studies within the predominantly epiphytic Polypodiaceae.
