9311687 Mishler This research involves the derivation of a detailed phylogeny of the aquatic fern family Marsileaceae using both morphological and molecular characters. This phylogeny will be used to examine the role of heterochrony as a means of generating morphological variation in ferns. %%% This family of ferns is unique in the development of leaf structures, and a detailed phylogeny will allow one to examine the details of developmental processes associated with leaf development. At the same time, the developmental information obtained from this study will serve as a case study for a general evaluation of relationships between developmental processes in ferns and fern phylogenies. ***
