Trees Worth Knowing Part 6

The pale brown wood of the white oak distinctly shows the narrow rings of annual growth. Each season begins with a coa.r.s.e, 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 leaf.a.ge takes its place, brightened by the yellow ta.s.sels 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 ill.u.s.tration, 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 cla.s.sed 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.

=The Post Oak=

_Q. minor_, Sarg.

The post oak has wood that is noted for its durability when placed in contact with the soil. It is in demand for fence posts, railroad ties, and for casks and boat timbers. "Iron oak" is a name that refers to the qualities of the wood. "Knees" of post oak used to be especially in demand.

In the Mississippi Basin this tree attains its largest size and greatest abundance on gravelly uplands. It is the commonest oak of central Texas, on the sandy plains and limestone hills. Farther north, it is more rare and smaller, becoming an undersized oak in New York and westward to Kansas.

In winter the post oak keeps its cloak of harsh-feeling, thick, coa.r.s.e-veined leaves. Tough fibres fasten them to the twigs. In summer the foliage ma.s.s is almost black, with gray leaf-linings. The lobes and sinuses are large and squarish, the blades four or five inches long. The limbs, tortuous, horizontal, form a dense head.

=The Chestnut Oak=

_Q. Prinus_, Linn.

The chestnut oak has many nicknames and all are descriptive. Its leaves are similar in outline and size to those of the chestnut. The margin is coa.r.s.ely toothed, not lobed, like the typical oak leaf.

"Tanbark oak" refers to the rich store of tannin in the bark, which makes this species the victim of the bark-peeler for the tanneries wherever it grows. "Rock chestnut oak" is a t.i.tle that lumbermen have given to the oak with exceptionally hard wood, heavy and durable in soil, adapted for railroad ties, posts, and the like.

Unlike other white oaks, the bark of this tree is dark in color and deeply fissured. Without a look at the leaves, one might call it a black oak.

The centre of distribution for this species seems to be the foothill country of the Appalachian Mountains, in Tennessee and North Carolina.

Here it predominates, and grows to its largest size. From Maine to Georgia it chooses rocky, dry uplands, grows vigorously and rapidly, and its acorns often sprout before falling from the cup!

The chestnut oak is one of the most desirable kinds of trees to plant in parks. It is symmetrical, with handsome bark and foliage. The leaves turn yellow and keep their fine texture through the season. The acorn is one of the handsomest and largest, and squirrels are delighted with its sweet kernel.

=The Mississippi Valley Chestnut Oak=

_Q. ac.u.minata_, Sarg.

In the Mississippi Valley the chestnut oak is _Q. ac.u.minata_, Sarg., with a more slender and more finely-toothed leaf that bears a very close resemblance to that of the chestnut. The foliage ma.s.s is brilliant, yellow-green, each leaf with a pale lining, and hung on a flexible stem. "Yellow oak" is another name, earned again when in autumn the leaves turn to orange shades mingled with red.

On the Wabash River banks these trees surpa.s.s one hundred feet in height and three feet in diameter. The base of the trunk is often b.u.t.tressed. Back from the rich bottom lands, on limestone and flinty ridges, where water is scarce, these trees are stunted. In parks they are handsome, and very desirable. The bark is silvery white, tinged with brown, and rarely exceeds one half an inch in thickness.

=The Swamp White Oak=

_Q. platanoides_, Sudw.

The swamp white oak loves to stand in wet ground, sometimes even in actual swamps. Its small branches shed their bark like the b.u.t.tonwood, the flakes curling back and showing the bright green under layer. On the trunk the bark is thick, and broken irregularly into broad, flat ridges coated with close, gray-brown scales often tinged with red.

[Ill.u.s.tration: _See page 65_

HORSE-CHESTNUT IN BLOSSOM]

[Ill.u.s.tration: _See page 83_

WEEPING WILLOW]

In its youth the swamp white oak is comely and symmetrical, its untidy moulting habit concealed by the abundant foliage. One botanist calls this species _bicolor_, because the polished yellow-green upper surfaces contrast so pleasantly with the white scurf that lines each leaf throughout the summer. Yellow is the autumn color. Never a hint of red warms this oak of the swamps, even when planted as a street or park tree in well-drained ground.

=The Basket Oak=

_Q. Michauxii_, Nutt.

The basket oak is so like the preceding species as to be listed by some botanists as the southern form of _Q. platanoides_. They meet on a vague line that crosses Maryland, Kentucky, and Tennessee. Both have large leaves silver-lined, with undulating border, of the chestnut oak pattern. Both are trees of the waterside, tall, with round heads of gnarled limbs. The red-tinged white bark sets the basket oak apart from all others. Its head is broader and its trunk stouter than in the other species. The paired acorns are almost without stalks, the nuts large, the kernels sweet. In autumn, farmers turn their hogs into the woods to fatten on this oak-mast. The edibility of these nuts may account for the common name, "cow oak."

The wood splits readily into thin, tough plates of the summer wood.

This is because the layer formed in spring is very porous. Bushel baskets, china crates, and similar woven wares are made of these oak splints. The wood is also used in cooperage and implement construction, and it makes excellent firewood.

=The Live Oak=

_Q. Virginiana_, Mill.

The live oak with its small oval leaves, without a cleft in the plain margins, looks like anything but an oak to the Northerner who walks along a street planted with this evergreen in Richmond or New Orleans.

It is not especially good for street use, though often chosen. It develops a broad, rounded dome, by the lengthening of the irregular limbs in a horizontal direction. The trunk becomes ma.s.sive and b.u.t.tressed to support the burden.

The "knees" of this oak were in keenest demand for ship-building before steel took the place of wood. In all lines of construction, this lumber ranks with the best white oak. The short trunk is the disadvantage, from the lumberman's viewpoint. Its beauty, when polished, would make it the wood _par excellence_ for elegant furniture, except that it is difficult to work, and it splits easily.

The Spanish moss that drapes the limbs of live oaks in the South gives them a greenish pallor and an unkempt appearance that seems more interesting than beautiful to many observers. It is only when the sight is familiar, I think, that it is pleasing. Northern trees are so clean-limbed and so regular about shedding their leaves when they fade, that these patient hosts, loaded down with the pendent skeins of the tillandsia, seem to be imposed upon. In fact, the "moss" is not a parasite, sapping the life of the tree, but a lodger, that finds its own food supply without help.

=California White Oak=

_Q. lobata_, Nee.