14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 82 



The so-called Kenai flora of Alaska was originally described by 

 Heer and additions to it have been published by Lesquereux and 

 Knowlton. Hollick has been engaged in a revision of this and related 

 floras from Alaska for a number of years, but his results are not 

 yet published. That from the type locality as listed by Hollick in 

 1915' comprised but 40 named species and contains not a single 

 tropical or subtropical type. Associated with the plants are thick 

 coal seams and fresh water mollusca (Unio, Anadon, Amicola, Mel- 

 ania), as well as beetle elytra. 



He states in a recent letter that localities in the southeastern coastal 

 region of Alaska (Alexander Archipelago) have yielded a Tertiary 

 flora that is distinctly indicative of warmer climatic conditions than 

 those from farther north, including cycads, palms, and such dicoty- 

 ledonous genera as Anona, Dillenia, etc., but he has not yet determined 

 whether they are the same or different in age. In either case they sup- 

 port the conclusion that climatic zoning is indicated. 



As listed by Knowlton" in 1919 the Kenai flora (so called) 

 comprised about 120 species. The most abundant forms are willows, 

 oaks, poplars, walnuts, beeches, birches, hazels, and alders — dis- 

 tinctly temperate, and cool rather than warm temperate types. Per- 

 haps the most abundant plants individually, certainly the widest rang- 

 ing geographically in northern latitudes (Holarctica), are the leaves 

 of hazel bushes (Corylus) . Of the 54 genera of Knowlton's list, the 

 following nine are not present in the existing flora of North America : 

 Ginkgo, Glyptostrohus, Taxites, Hcdera, Paliuriis, Elacodcndron, 

 Pterospermitcs, Trapa, and Zizyphus. 



It may seem that I am juggling the evidence in omitting these nine 

 genera from further consideration, but let me point out that the three 

 of these about which there seems to^ be no doubt regarding their iden- 

 tity, namely. Ginkgo, Trapa, and Glyptostrohus, are all temperate 

 types in the existing flora. The remaining six genera are under more 

 or less suspicion of quite a dififerent order from any differences of 

 opinion among paleobotanists regarding the identification of the hazels, 

 birches, alders, etc., with which they are associated. Opinion might 

 differ as to whether a particular species of the latter was a Betula or 

 Alnus, an Uhnus or a Carpimis, or a Plancra; or whether one or 

 several species of Corylus should be recognized as distinct species ; but 

 opinion is unanimous that the choice is thus narrowed, whereas in the 

 case of such things as Taxites — all any one knows is that it represents 



• Hollick, A., U. S. Geol. Surv. Bull. 587, PP. 88-89, iQiS- 

 ■Knowlton, F. H., U. S. Geol. Surv. Bull. 696, pp. 786-789, 1919. 



