The McAbee flora of British Columbia and its relation to the Early-Middle Eocene Okanagan Highlands flora of the Pacific Northwest

摘要

Megafossils and pollen data are used to compare the flora found at the McAbee site, located near the town of Cache Creek, British Columbia, to six other well-collected Eocene lacustrine floras of Washington and western British Columbia. A diverse flora is found at McAbee consisting of at least 87 taxa. Gymnosperms are common, including sixteen separate species, 14 conifers and two ginkgos. A minimum of 67 angiosperm genera are represented in the flora, many yet to be described. The dominant dicotyledonous elements of the leaf assemblage at McAbee include Fagus (also represented by nuts and cupules) with Ulmus and representatives of the Betulaceae, especially Betula and Alnus. The confirmation of Fagus, also rarely found from sites at Princeton, British Columbia, and Republic, Washington, provides the oldest well-documented occurrence of the genus, predating the Early Oligocene records of Fagus previously reported for North America, Asia, and Europe. Data provided by pollen analysis broadens otir knowledge of the McAbee flora. Angiosperm pollen typically predominates over gymnosperms with the Ulmoideae and Betulaceae being the most common angiosperm pollen types. Members of the Pinaceae dominate the gymnosperm pollen record. Paleoclimatic estimates for McAbee are slightly cooler than for the Republic and Princeton localities and thermophilic elements, such as Sabal found at Princeton or Ensete and Zamiaceae found at Republic are not known from McAbee.