Quercus Alba - Description

Description

Normally not a very tall tree, typically reaching 65–85 feet (19.5-25.5 m) at maturity, it nonetheless becomes quite massive and its lower branches are apt to extend far out laterally, parallel to the ground. The tallest known white oak is 144 feet (43 m) tall. It is not unusual for a white oak tree to be as wide as it is tall, but specimens growing at high altitudes may only become small shrubs. White oaks have been known to live up to six hundred years. The bark is a light ash-gray and peels somewhat from the top, bottom and/or sides.

In spring the young leaves are of a delicate, silvery pink and covered with a soft, blanket-like down. The petioles are short, and the leaves which cluster close to the ends of the shoots are pale green and downy with the result that the entire tree has a misty, frosty look. This condition continues for several days, passing through the opalescent changes of soft pink, silvery white and finally yellow green.

The leaves grow to be 5-8.5 inches long and 2.75-4.5 inches wide and have a deep glossy green upper surface. They usually turn red or brown in autumn, but depending on climate, site, and individual tree genetics, some trees are nearly always red, or even purple in autumn. Some brown, dead leaves may remain on the tree throughout winter until very early spring. The lobes can be shallow, extending less than halfway to the midrib, or deep and somewhat branching. The acorns are usually sessile, and grow to 0.5-1 inch in length, falling in early October.

Quercus alba is sometimes confused with the swamp white oak, a closely related species, and the bur oak. The white oak hybridizes freely with the bur oak, the post oak, and the chestnut oak.

• Bark: Light gray, varying to dark gray and to white; shallow fissured and scaly. Branchlets at first bright green, later reddish-green and finally light gray. A distinguishing feature of this tree is that a little over halfway up the trunk the bark tends to form overlapping scales that are easily noticed and aid in identification.
• Wood: Light brown with paler sapwood; strong, tough, heavy, fine-grained and durable. Specific gravity, 0.7470; weight of one cubic foot, 46.35 lbs; weight of one cubic meter 770 kg.
• Winter buds: Reddish brown, obtuse, one-eighth of an inch long.
• Leaves: Alternate, five to nine inches long, three to four inches wide. Obovate or oblong, seven to nine-lobed, usually seven-lobed with rounded lobes and rounded sinuses; lobes destitute of bristles; sinuses sometimes deep, sometimes shallow. On young trees the leaves are often repand. They come out of the bud conduplicate, are bright red above, pale below, and covered with white tomentum; the red fades quickly and they become silvery greenish white and shiny; when full grown they are thin, bright yellow green, shiny or dull above, pale, glaucous or smooth below; the midrib is stout and yellow, primary veins are conspicuous. In late autumn the leaves turn a deep red and drop, or on young trees remain on the branches throughout the winter. Petioles are short, stout, grooved, and flattened. Stipules are linear and caducous.
• Flowers: appear in May, when leaves are one-third grown. Staminate flowers are borne in hairy aments two and a half to three inches long; the calyx is bright yellow, hairy, six to eight-lobed, with lobes shorter than the stamens; anthers are yellow. Pistillate flowers are borne on short peduncles; involucral scales are hairy, reddish; calyx lobes are acute; stigmas are bright red.
• Acorns: Annual, sessile or stalked; nut ovoid or oblong, round at the apex, light brown, shining, three-quarters to an inch long; cup-shaped, enclose about one-fourth of the nut, tomentose on the outside, tuberculate at base, scales with short obtuse tips becoming smaller and thinner toward the rim.