CALLIXYLON FROM THE UPPER DEVONIAN OF NORTHWESTERN ALBERTA

Campbell, J. D. (Res. Council Alberta, Edmonton.) Callixylon from the Upper Devonian of northwestern Alberta. Amer. Jour. Bot. 50(7): 648–652. Illus. 1963.—An oil-well core from the “Granite Wash” of probable early Late Devonian age (Wood bend equivalent) in the Peace River region of northwestern Alberta yielded a thin pyritized chip of coniferoid wood. The pith is not represented, but the secondary tracheid pitting, exhibiting radially aligned clusters of 5–10 araucarioid pits, indicates that the specimen is referable to the wood-type usually called Callixylon, now believed to be the axis of the leaf-genus Archaeopleris. In its low and regularly uniseriate or rarely biseriate rays, with no apparent ray tracheids, the specimen may resemble the species Callixylon trifdievi Zalessky (1909) from the Upper Devonian of Russia, and thus lend some small support to the postulation of a Late Devonian land connection between northwestern North America and Europe.