Part 51

Growth Form: Medium to large tree up to 80 feet tall; trunk diameter up to 3 feet; crown rounded to oblong, with several branches, the lowermost often drooping; trunk straight, columnar.

Bark: Gray or grayish-brown, divided into flat, sometimes squarish, plates.

Twigs: Slender, smooth, buff-colored; pith star-shaped in cross-section; leaf scars alternate, but clustered near the tip of the twig, half-round, slightly elevated, with several bundle traces.

Buds: Nearly round, smooth, pale brown, up to ⅛ inch long.

Leaves: Alternate, simple; blades divided into 5-7 rounded lobes, the sinuses shallow to deep, up to 10 inches long, up to 4½ inches broad, dark green and smooth on the upper surface, pale and softly hairy to nearly smooth on the lower surface; leafstalk up to 1 inch long, smooth or hairy.

Flowers: Staminate and pistillate borne separately, but on the same plant, appearing when the leaves begin to unfold, minute, without petals, the staminate in slender, yellow, drooping catkins, the pistillate few in a group.

Fruit: Acorns solitary or 2 together, with or without a stalk, the nut nearly spherical, up to 1 inch in diameter, pale brown, often nearly entirely enclosed by the cup, the cup finely hairy, with some of the scales forming a ragged rim near the base.

Wood: Hard, heavy, strong, dark brown.

Uses: Interior finishing, cabinets, fuel, fence posts.

Habitat: Bottomland woods; swamps.

Range: Southern Virginia across to eastern Texas, north up the Mississippi Valley to southern Missouri, southern Illinois, and southern Indiana; also in Delaware, Maryland, and New Jersey; southward to Florida.

Distinguishing Features: The best identifying characteristic of this plant is the acorn in which the nut often is nearly enclosed by the cup.

BUR OAK Quercus macrocarpa Michx.

Other Name: Mossy-cup Oak.

Growth Form: Large tree up to 120 feet tall; trunk diameter up to 5 feet; crown rounded, with stout branches; trunk straight, stout, sometimes slightly buttressed at the base.

Bark: Dark brown or yellow-brown, rather deeply furrowed.

Twigs: Stout, dark brown, often with corky ridges; pith star-shaped in cross-section; leaf scars alternate but clustered near the tip, half-round, slightly elevated, with several bundle traces.

Buds: Rounded or slightly pointed at the tip, yellowish-brown to reddish-brown, finely hairy.

Leaves: Alternate, simple; blades broader at the upper end, coarsely round-toothed, usually with a pair of deep sinuses just below the middle, often with as many as 5-7 lobes, the lobes not bristle-tipped, dark green and smooth or slightly hairy on the upper surface, paler and softly hairy on the lower surface, up to 14 inches long and 7 inches wide; leaf stalks up to 1 inch long, stout, smooth or finely hairy.

Flowers: Staminate and pistillate borne separately, but on the same tree, appearing as the leaves begin to unfold, minute, without petals, the staminate in slender, drooping catkins, the pistillate few in a group, with red stigmas.

Fruit: Acorn usually solitary, with or without a stalk, the nut ovoid to ellipsoid, dark brown, up to 1¾ inches long, the cup covering half to nearly all the nut, hairy, the lowermost scales long-fringed.

Wood: Heavy, hard, durable, close-grained, brown.

Uses: Cabinets, ship-building, fenceposts, fuel, tight cooperage.

Habitat: Dry ridges to bottomland woods.

Range: Vermont across to North Dakota, south to Texas, east to Arkansas, Tennessee, and Maryland.

Distinguishing Features: The leaves of the Bur Oak are distinctive because they are very broad in the upper half with a pair of deep sinuses a little below the middle. The large, fringed cups are also distinctive.

BLACKJACK OAK Quercus marilandica Muench.

Other Name: Scrub Oak.