Pollen and Anther Ontogeny in Brasenia (Cabombaceae, Nymphaeales)
Mackenzie L. Taylor
Dr. Jeffrey M. Osborn, Faculty Mentor
Brasenia schreberi, commonly known as the Water Shield, is a water lily sporadically distributed throughout temperate and tropical regions of the Americas, Asia, Australia, and Africa. Evidence indicates that water lilies are among the most primitive flowering plants. Despite their usefulness in determining evolutionary relationships, pollen characters have not been well documented in Brasenia. In this presentation, pollen and anther ontogeny will be described for Brasenia. Anthers have been studied using scanning electron, transmission electron, and light microscopy and pollen at all major ontogenetic stages was compared with regard to formation of pollen wall layers. The infratectal collumellae develop first, followed by discontinuous development of the tectum. Variation in tetrad geometry has been identified and surface ornamentation has been characterized. Several characters appear to be correlated with wind-pollination and the adaptive significance of these characters, in contrast to those of Cabomba, the fly-pollinated second genus within Cabombaceae, will be discussed.
Keywords: Brasenia, water lillies, Nymphaeales, pollen, pollen ontogeny, pollen development, aquatic plants, Cabombaceae
Presentation Type: Oral Paper
Location: VH 1432