PERMINERALIZED FAGUS NUTS FROM THE EOCENE OF VANCOUVER ISLAND, CANADA

Sixty trigonal fagaceous fruits have been identified in the calcareous nodules from the Eocene Appian Way locality of Vancouver Island, British Columbia, Canada. The anatomically preserved fruits are known at various developmental stages. In transverse section, fruits are triangular, with lateral ridges that vary in shape from rounded to sharply angled. In longitudinal section, the nuts show a broad base and a tapered apex. The ovary is partitioned into three locules at the apex, and placentation is axile, with two ovules per locule. Locules merge near the base, giving the appearance of a three-lobed ovarian cavity. This area is occupied by a single seed at maturity. The inner wall of the endocarp is tomentose. Major vascular bundles in the mesocarp occur midway between and at the lateral ridges of the nut. The nut is wingless and has an exocarp of dense sclerenchyma interrupted at the ridges by dehiscence lines that traverse the entire fruit wall. The nut surface is glabrous, except near the distal end, where trichomes emerge in proximity to three styles and surrounding perianth remnants. These nuts are assigned to the genus Fagus L. and represent the first permineralized Fagaceae of subfamily Fagoideae in the fossil record. Fagus schofieldii sp. nov. provides the earliest evidence of winglessness in Fagoideae and supports the possibility of a North American origin for the genus.