North-western corner of the state, which lies in the Boreal zone.
He further found that there was an element which he termed boreal in a more intense degree, which amounted to about a fifteenth of the whole flora.
In connexion with the objection based upon the sub-boreal character of the regions which were the cradle of the Aryans, as proved by the so-called palaeontology of the Aryan languages, it may be observed that by the end of the Glacial, and during the earlier Lacustrine (Post-Glacial) period, the vegetation of Turkestan and of Central Asia was quite different from what it is now.
There are firs and spruces on the mountains, characteristic of the Boreal zone; pines characteristic of the Transition zone; pinon juniper, greasewood and the universally conspicuous sage-brush, characteristic of the Upper Sonoran zone.
The boreal embraces the highest mountain altitudes; the transition belts it on both sides of the continental divide; the upper Sonoran takes in about the eastern half of the plains region east of the mountains, and is represented further by two small valley penetrations from Utah.