Using phylogeny to investigate the history of morphological evolution in heterosporous ferns

This project is a collaborative research effort among three co-investigators:
Kathleen M. Pryer, Duke University, Harald Schneider, Universtiy of Goettingen, Germany; and Richard A. Lupia, University of Oklahoma, Norman.

Throughout the evolutionary history of land plants there have been repeated re-invasions of aquatic environments by terrestrial plants from distantly related groups. In order to survive these very different physical conditions, these plants have had to dramatically modify their vegetative, reproductive, and dispersal systems.

Few living ferns are aquatic, most are terrestrial and homosporous. The exceptions are heterosporous ferns, with morphologically distinct spores producing unisexual gametophytes. Heterosporous ferns are monophyletic and comprise two extant families, the semi-aquatic Marsileaceae and the aquatic Salviniaceae. Except for very recent interest in the relationships among the five extant heterosporous genera, these ferns have been largely ignored in systematic studies and infrageneric relationships are virtually unknown.

Heterosporous ferns are relative newcomers that diversified during the Cretaceous, at the same time as flowering plants. The fossil record has preserved a rich history of these ferns, mostly in the form of microfossils with a remarkable diversity of ornamented spores.

The primary goal of our research is to reconstruct a comprehensive phylogeny for the heterosporous aquatic ferns (Marsileaceae and Salviniaceae), including living and fossil members, incorporating data from multiple genes, morphology, and developmental studies for the living taxa, and integrating morphological data from fossil taxa.

More information about the project is available on Kathleen M. Pryer website.

The project is funded by National Science Foundation Collaborative Research award 0089909.

COLLECTIONS | Vascular Plants | Algae | Bryophytes | Fungi | Lichens

Duke University Herbarium