390 ABOUT THE OAKS OF THE UNITED STATES. 
We feel satisfied that we might have abundant material to characterize several distinct species, 
certainly 4 or 5 well-marked forms, and, indeed, they have been considered such. The first is Nut- 
tall’s Quercus Gambelii (Q. stellata, var. Utahensis, D.C. Prod.) ; the second is Q. alba, var. Gunnisoni, 
of Torrey; the third, with acutish lobes or coarse teeth, is Torrey’s old Q. undulata of Long’s Expe- 
dition, the first oak obtained from these mountains, and described about fifty years ago; the fourth, 
from the edge of the precipice itself, is what has often been mistaken for Torrey’s Q. Zmoryi, or what 
has been named Q. pungens, Liebm., in part; with it occur entire-leaved forms, which seem to unite 
with this as a fifth form the @Q. oblongifolia, of the same author, and Q. grisea, Liebm. As a large 
and broad-leaved southeastern form, somewhat allied to QY. Gambelii, I consider Q. Drummondii, 
Liebm. In herbarium specimens they all appear distinct enough, but, looking around 
us, the very abundance of material must shake our confidence in our discrimination: [374 (3)] 
within the compass of a few hundred yards we find not only the forms above distin- 
guished, but numbers of others, which are neither the one nor the other, but which are intermediate 
between them, and clearly unite them all as forms of one single extremely polymorphous species. 
If one oak behaves thus, why not others? Thrown into a sea of doubt, what can guide us toa 
correct knowledge ? 
Though oaks are so common and such well-studied plants, I venture in the following pages to 
repeat old observations, in order to combine with them some which I think are new, and which will 
help to throw a little more light on the subject. 
The TRUNK —its BARK, as well as its WooD —is what we first contemplate, and this at once 
takes us to one of the principal points I wish to discuss. 
That the trunk is that of a large, sometimes one of the largest, or of a middle-sized tree, or 
occasionally that of a shrub, even a very low one, is well known. On the Atlantic slope of the 
continent most species of oaks make trees, and only a few are known as shrubs; I can now recall 
not more than one species, the live-oak of the south, which occurs in both forms: usually an 
immense tree, it occasionally bears a rich harvest of fruit as one of the smallest bushes. But it is 
different on the Pacific slope; there we find many oaks as trees in the lower countries, and as 
shrubs, usually with smaller foliage and smaller fruit, in the mountains. The lesser number of oaks 
seem to occur solely in one or in the other of these forms. 
Examining the bark, we at once become aware of the fact that the popular distinction of 
“ white-oaks ” and “ black-oaks ” is based on correct observation. The paler, ashy-gray bark of the 
former, and the darker, often nearly black, color of the latter corresponds, as will be shown, with 
other essential characters, and well marks the two principal groups of our American oaks. The 
bark of the white-oaks is inclined to be scaly or flaky, that of the black-oaks is usually rougher, 
and deeply cracked and furrowed. 
The wood of the white-oaks is tougher, heavier, and more compact, — the only — which 
is fit to be used by the wheelwright or cooper, and is for their purposes unsurpas 
The wood of the black-oaks is brittle and porous, makes poorer firewood, and, made [375 (4)] 
barrels, holds only dry substances. Undoubtedly the microscopical investigation of both 
classes of oak-wood will scientifically establish and confirm these distinctions. 
While many other trees, such as Pines, Walnuts, Hickories, Gleditschia, ete., grow rapidly in 
the first decades of their life, and make narrower and narrower annual rings as they grow older, the 
oaks either hold their own, the annual rings being as wide in age as they are in youth, or they grow 
more any after the first 50, or 100, or even 150 years of their existence. 
WINTER-BUDS, especially the terminal ones, show some characteristic differences ; they are 
ince or smaller, acute or obtuse, smoothish, or hairy, or tomentose; Quercus Garryana can be 
readily distinguished from all the allied Californian oaks by its large, pointed, tomentose winter-buds. 
