24 WEST AMERICAN OAKS. 



{Q. alba) of the Eastern United States than to any other. If it were reducible, as a 

 variety, to any older species, Dr. Torrey's trinomial, Q. alba Gtinntsonu, would, in my 

 judgment, be its name. 



No one of the ten botanical writers whose names are cited in the bibliography, ever 

 saw the species, except in that reduced and shrubby form which assumes at the extreme 

 northern limit of its geographical range. Only two or three of them have seen so much 

 as that. 



It has been my privilege to become familiar with it, not only during three years of 

 field work in middle and southern Colorado. I have traced it all the way from the head 

 waters of the Platte and the Arkansas, down the Rio Grande del Norte to southern New 

 Mexico ; thence westward into those elevated forest regions of the Pinos Altos, Mogollones 

 and San Francisco Mountains of New Mexico and Arizona, where the species is really at 

 home, and where it takes on the dimensions and the comeliness of a dignified forest tree. In 

 those remote and still almost untraveled southwestern woods, not one of the botanists, who 

 have hitherto passed judgments upon its rank and its relationship, has ever seen it. 



Dr. Kellogg in his drawing has paid his tribute of deference to what, a few years ago, 

 was the newly promulgated teaching of Dr. Engelmann, that Q. undulata and Q. Gambelii 

 are one species. He has interlaced the foliage of a small and spinose-toothed evergreen, 

 with that which plainly belong to a deciduous tree and is deeply sinuate-pinnatifid ; and, 

 under the joint figure of the two he wrote the one name "<2. undulataP The species last 

 named, and Q. Gambelii I am persuaded are about as distinct as any two species of this 

 white oak series inhabiting one region. It ought to be enough for the defense of this pro- 

 position to say that the former is an evergreen shrub, the latter a deciduous tree. But that 

 is not all. The two appear to be genetically very widely separated. There is evidence that 

 while Q. Gambelii is the westermost representative of the group of Atlantic American 

 deciduous white oaks, Q. undulata is the most easterly species of the Pacific persistent- 

 leaved group. 



I have remarked in the introductory pages that the Pacific Coast white oaks are more 

 like those of the Old World than they are like those of the Atlantic side of the continent. 

 The long and dry summer season of California, lasting as it does from March until 

 November, may have developed, in such trees as Q. lobata and Q. Garryana for example, 

 that remarkable firmness of texture in the foliage which is one of the points wherein they 

 differ from their eastern analogues. None of our species have the habit of retaining their 

 leaves in a dead and dry faded and papery condition during the winter months. But the 

 eastern white oaks do so; at least Q. alba, the young thickets of which, at least in the 

 northern and middle States, are clad in a full vesture of pale and drooping thin-parch- 

 ment-like dead foliage throughout all or the greater part of the winter. And Q. Gambelii 

 has the comparatively thin leaves of the eastern white oak, and, in young trees, there is the 



