POST OAK
(Quercus Minor)

Post oak is the most common name for this tree but various sections of its range have given it their own names which probably have local significance. The following names are in use in the localities denoted: post oak in the eastern and Gulf states, Connecticut to Texas, and in Arkansas and West Virginia; box white oak in Rhode Island; iron oak in Delaware, Mississippi and Nebraska; chÊne Étoile in Quebec; overcup oak in Florida; white oak in Kentucky and Indiana; box oak and brash oak in Maryland.

Toward the northern portion of the range of this tree it is small, and in early times it was little used except for fence posts. Its durability fitted it for that use, and it is said the common name was due to that circumstance. The name iron oak was used by shipbuilders who sometimes bought small knees made of this wood. Baltimore oak was an early name which is not now in use. It was generally applied to white oak, but it included some post oak shipped from the Chesapeake bay region.

Post oak is botanically and commercially a white oak and is seldom distinguished from the true white oak, Quercus alba, in commerce. It is seen at its best in the uplands of the Mississippi basin and in the Gulf states west of the Mississippi, where it attains a considerable size. In the northeastern states and in Florida it is small, becoming shrubby in some localities, and more or less of local growth. Limestone uplands or dry, sandy or gravelly soils seem to offer the best conditions for its existence, where it grows in company with black jack, red and white oak, sassafras, dogwood, gums, and red cedar.

The range of growth of post oak extends from New Brunswick south through the Atlantic states into Florida; west through the Gulf states and throughout the Mississippi river system, growing west brokenly to Montana. It is the common oak of central Texas but in the North it is rather scarce, becoming more plentiful in the lower Appalachians.

The broad, dense, round-topped crown of the post oak with its peculiar foliage make it very noticeable in the woods, even to the casual observer. Its dark green looks almost black at a distance. The tree has an average height of sixty or eighty feet and is about two feet in diameter, but in exceptional cases it reaches one hundred feet in height and has a diameter of three feet. It has a moderately thick, dark brown bark with a reddish tinge and deep fissures, the broad ridges being covered with thin scales. On the branches it becomes much thinner, and lighter in color, the branchlets being unfissured and glabrous in the second year, although fuzzy at first. They are rather heavy and rounded and terminate in short round buds with conspicuous scales. A noticeable feature of the tree is the peculiar branching. The limbs are heavy and crooked, separating often, with wide angles, forming knees which when big enough, have a commercial value.

When the tree is in foliage the tufted appearance of the leaves grouped on the ends of the twigs gives it a distinctive look. They bear some resemblance to a star, and for that reason some botanists have named the species stellata. The leaves are five or seven inches long usually, but in some cases, especially on young specimens, they are ten or more inches long. They are dark, shiny-green and on a short petiole, the veins and midrib being heavy and conspicuous. The identification of these leaves is easy as they are heavy in texture, are bilaterally developed with a large, obtuse lobe on each side about in the middle, giving them a maltese cross effect. They are very persistent, staying on the tree until the new leaves push them off in the spring.

The form of post oak is not ideal from the lumberman’s viewpoint. The tree does not prune itself well. Straggling limbs adhere to the trunk and prevent the clean bole which often makes white oak so attractive.

The wood weighs 52.14 pounds per cubic foot. The name iron oak referred to the weight as well as the strength of the wood. It is rather difficult to season, and is inclined to check badly. The medullary rays are broad and numerous, and checking is apt to develop along the rays. The summerwood occupies about half of the annual ring, and is dense and dark colored. Large pores are abundant in the springwood, and smaller ones in the summerwood.

Formerly this tree was known in some sections as turkey oak, though the name is no longer heard, but is now applied to another oak in the South. The acorns are small enough to be eaten by turkeys, and when those game birds were wild in the woods they frequented parts of the forests where post oaks grew, and hunters knew where to find them. The uses of post oak for building and manufacturing purposes are the same as for white oak as far as they go, but post oak is not so extensively employed.

The earliest railroads in America were built in the region where post oak of excellent quality grew, and it saw service from the first as crossties, and car and bridge timbers. It is still used for those purposes. Its other important uses are as furniture material, both as solid stock and veneer; interior finish and fixtures for offices, banks, and stores; musical instruments, including frames, braces, and veneers; baskets, crates, and shipping boxes; vehicles, particularly tongues, axles, and hounds of heavy wagons; flooring, stair work, balusters.

Post oak will do well on land too gravelly and thin to sustain good white oak growth. To that extent the two species are not competitors for ground, and post oak is assured a place in future woodlots, but it cannot be expected ever to equal white oak in commercial importance, while as an ornamental tree it is not usually favored because the shape of its crown is not altogether pleasing. Its very dark foliage, however, is admired by many and gives the tree an individuality.

Swamp White Oak (Quercus platanoides). This tree’s botanical name means “broadleaf oak,” and that is a good description as far as it goes, but it does not apply solely to this species. The characteristic which fixes it best in the minds of most people is its preference for low, wet soil. Its two common names are swamp oak and swamp white oak, yet it is not really a swamp tree, such as the northern white cedar, southern white cedar, cypress, and tupelo are. It does not associate with any of those trees. It prefers river banks, and does not object to a good deal of water about its roots, though it grows nicely in situations out of reach of all overflow, and often side by side with silver maple, hickory, ash, and several other oaks. The leaf resembles that of chestnut oak, and the bark is somewhat like chestnut oak, but the wood passes in market for white oak, and is a good substitute for it, though the resemblance is not so close that one need be mistaken for the other. The tree averages about seventy feet high with a diameter of two feet, but much larger trunks are common. The famous “Wadsworth oak,” which stood on the bank of the Genesee river in western New York, about a mile from the village of Geneseo, was a swamp white oak. It had a trunk diameter of nine feet, but it was not tall in proportion. It met its overthrow by the undermining of the river bank in time of flood. That is a common fate for this tree, because of its preference for river banks. Its range is from Maine to Wisconsin and Iowa. It follows the mountains to northern Georgia; and west of the Mississippi it grows as far south as Arkansas. The species is best developed in western New York, northwestern Pennsylvania, and along the southern shores of Lakes Erie and Michigan.

Trees do not clear themselves of branches on their lower trunks very early in life, and lumber more or less knotty results. It is possible, however, to cut a fairly large proportion of clear boards. The wood is of about the same weight as white oak, and is hard, strong, and tough. Its color is light brown, and the thin sapwood is hardly distinguishable from the heart. The medullary rays are as large as those of white oak, but are few. For that reason, swamp white oak does not give very satisfactory results when quarter-sawed. The bright patches are too scarce. Neither does it show as many of these rays as chestnut oak. The wood is very porous, but the large pores are confined to the springwood, while the broad bands of summerwood are dense. The contrast between the two parts of annual rings forms a strong, but not particularly handsome figure when the lumber is sawed tangentially—that is, from the side of the log. The wood finisher can improve this oak’s natural appearance by employing fillers and stains to lighten shades or deepen tints. The uses of this oak are numerous. It is excellent fuel, and is rather low in ash; it is weaker and more brittle than white oak; but it is quite satisfactory for railroad ties, car building, house finish, furniture, some parts of heavy vehicles, certain kinds of cooperage, and for farm implements.