The pale brown wood of the white oak distinctly shows the narrow rings of annual growth. Each season begins with a coarse, porous band of "spring wood," followed by a narrower band of fine, close-grained "summer wood." White oak is streaked with irregular, dark lines. These are the porous lines of spring wood, discolored by foreign matter. Count them, allow a year for each, and you know how long one white oak tree required to make an inch of wood.
The supreme moment in the white oak's year comes in spring, when the gray old tree wakes, the buds swell and cast off their brown scales, and the young leaves appear. The tree is veiled, not with a garment of green, but with a mist of rose and silver, each twig hung with soft limp velvety leaves, red-lined, and covered with a close mat of silky hairs. It is a spectacle that seems unreal, because it is so lovely and gone so soon. The protecting hairs and pigments disappear, and the green leafage takes its place, brightened by the yellow tassels of the stamen flowers, and the growing season is on.
In autumn the pale-lined leaves of the white oak turn slowly to sombre violet and dull purplish tones. Clinging there, after the acorns have all fallen and been gathered by squirrels, the foliage fades into the gray of the bark and may persist until spring growth sets in.
The Bur Oak
Q. macrocarpa, Michx.
The bur oak (see illustration, [page 39]) is called the mossy-cup on account of the loose, fringed scales about the rim of the cup that holds the large acorn—largest in the whole oak family. Often the nut is completely enclosed by the cup; often it is small. This variable fruit is sweet, and it is the winter store of many furry wood-folk.
The leaf has the rounded lobing of the family, with the special peculiarity of being almost cut in two by a pair of deep and wide opposite sinuses, between the broad middle, and the narrow, tapering base. Not all leaves show this odd form, but it is the prevailing pattern. The dark green blade has a pale, fuzzy lining, that lasts until the leaves turn brown and yellow.
The bur oak is a rugged, ragged tree, compared with the white oak. Its irregular form is picturesque, its wayward limbs are clothed in a loose garment of untidy, half-shed bark. The twigs are roughened with broad, corky wings. The trunk is brownish, with loosened flakes of gray, separated by shallow fissures.
The wood is classed with white oak, though darker in color. It has the same ornamental mirrors, dear to the heart of the cabinet-maker. It serves all the purposes for which a tough, strong, durable wood is needed.
The range of the species is from Nova Scotia to Montana, and it grows in large tracts from Winnipeg to Texas, doing well in the arid soil of western Nebraska and Dakota. Suckers from the roots spread these trees till they form the "oak openings" of the bluffs of the Missouri and other streams of Iowa and Minnesota. In Kansas it is the commonest oak tree. The largest trees of this species grow in rich bottom lands in the Ohio Valley.