Paleobotanical studies of the Appian Way fossil locality

The Eocene Appian Way locality of Vancouver Island, British Columbia, Canada, has been surveyed for plant fossils. More than sixty taxa of mosses, ferns, conifers and flowering plants have been identified. This dissertation presents data on five new fossil taxa in three vascular plant families (Gleicheniaceae, Platanaceae and Fagaceae). The plants are anatomically preserved in calcium carbonate concretions, often at different developmental stages. This three-dimensional preservation allows for correlation of internal anatomy to external morphology. A branching fern rhizome and associated stipes are described and placed in the family Gleicheniaceae based on stelar anatomy and leaf trace divergence. The protostelic rhizome is designated as a new species of the extant genus Gleichenia and is the only Cenozoic fossil record of the family in North America. Globose, staminate inflorescences of Platanaceae (sycamores) from the locality have five-parted flowers with in situ pollen and rudimentary carpels. This is the first occurrence of rudimentary bisexuality in the fossil record of the family and the inflorescences are described as a new genus, Gynoplatananthus. Cupules and nuts of the beech family (Fagaceae) are the most common angiosperm fruiting structures in the concretions. The three species described in this thesis represent both Castaneoideae and Fagoideae, the two major subfamilies of Fagaceae. Trigonal, wingless, single-seeded, tricarpellate nuts are placed as a fossil species of the genus Fagus and represent the earliest wingless fruits of subfamily Fagoideae. Two species of spiny, cupulate, ovoid to globose fruits are described and placed in a new genus, Cascadiacarpa. They differ from all extant and fossil species of Fagaceae in being strictly bicarpellate. Their placement in subfamily Castaneoideae is supported by a phylogenetic analysis of morphological characters. The diversity and abundance of Fagaceae at the locality supports a Paleogene radiation of the family. A framework for studying fossil plants from the Appian Way locality has been established and taxa described, thus far, suggest a unique and diverse assemblage that will broaden our understanding of Eocene vegetation.