DILLHOFF, RICHARD M.1,2*, ESTELLA B. LEOPOLD2, and STEVEN R. MANCHESTER3. 1Evolving Earth Foundation, 1217 212th Ave NE, Sammamish, Wa, 98074; 2University of Washington, Department of Botany, Box 351330 Room 241 Johnson Hall, Seattle, Wa, 98195; 3Florida Museum of Natural History, Dickinson Hall PO Box 117800, University of Florida, Gainesville, Fl, 32611. - The McAbee Flora and its Relation to the Proposed Middle Eocene “Okanogan Highlands” flora of the Pacific Northwest.
The concept of an “Okanogan Highlands” flora has come into common
usage to describe as many as six roughly co-eval Middle Eocene
lacustrine floras extending from Northern Central Washington into
Central British Columbia. While early publications exist for the
Eocene localities of British Columbia, only Republic and Princeton
have recent, detailed floral descriptions on which to base
comparisons. We have begun a comprehensive investigation of the McAbee
site, near Kamloops, British Columbia. Megafossils and pollen are used
to infer climate and compare the flora found at the McAbee site to
that at Republic and Princeton as well as approximately co-eval
lowland assemblages in the Puget Group and Chuckanut formations.
Conifers are common and diverse at McAbee, with at least twelve
separate taxa present. There are also at least twenty two angiosperm
genera with many yet to be described. The dominant dicot leaf taxon at
McAbee is Fagus which is also represented by nuts and cupules. The
confirmation of Fagus, also recognized from Princeton and Republic,
provides the oldest well documented occurrence of the genus, predating
the early Oligocene records of Fagus previously reported for North
America, Asia and Europe. McAbee apparently lacks thermophilic
elements such as Sabal, found at Princeton or Ensete and Dioon found
at Republic. It also appears to lack the diversity seen at Republic,
although this may be an artifact of the intensive public collecting
done there in recent years. In summary, the McAbee site appears to be
a good fit overall for the Okanogan Highlands floral construct but
also has unique elements that expand our knowledge of the Middle
Eocene flora of the Pacific Northwest.
Key words: Eocene, Fagaceae, McAbee, Middle, paleobotany, tertiary