Mindell, Randal , Stockey, Ruth A. , Beard, Graham .
Anatomically preserved staminate inflorescences of Platanaceae from the Eocene of Vancouver Island, British Columbia.
Anatomically preserved specimens of globose staminate inflorescences belonging to Platanaceae have been found in concretions at the Eocene Appian Way fossil locality on Vancouver Island, British Columbia, Canada. Using the cellulose-acetate peel technique, scanning electron microscopy and AMIRA 3.1 three-dimensional visualization software, details of floral structure, vascular architecture and pollen morphology were examined. Inflorescences measure between 9.0-9.5 mm in diameter, with numerous hypogenous flowers clustered around a receptacular head. Vascular tissues of the inflorescence originate from a central core and individual pentagonal traces supply the flowers. As the vascular tissue moves into the flower, single traces supply carpels and stamens. The base of each individual flower shows what appears to be a perianth of thin tepals. Five stamens that alternate with the carpels are 2.0—3.0 mm long and have elongate anthers with a thick connective and pollen sacs with massive clusters of in situ tricolpate pollen 16 μm in diameter. These grains show tectate-columellate wall structure with a reticulate exine. There is a single whorl of five, rarely four, free carpels that are ovate in longitudinal section and roughly triangular in transverse section. Singly-borne ovules can be seen within these carpels, though the gynoecium is otherwise undeveloped. These staminate inflorescences compare most closely to those of Platananthus sp. However, the presence of both stamens and carpels in the same flower has not previously been reported in the fossil record. These specimens add to our knowledge of the Appian Way flora and the diversity of fossil Platanaceae in the Tertiary.
1 - Vancouver Island Paleontological Museum, 151 West Sunningdale, Qualicum Beach, British Columbia, V9K 1K7, Canada
2 - University of Alberta, Department of Biological Sciences, CW 405 Biological Sciences Building, Edmonton, Alberta, T6G 2E9, Canada
Presentation Type: Paper
Location: Maybird (Cliff Lodge)
Date: Wednesday, August 4th, 2004
Time: 11:00 AM