Carlyle Lake

Redirecting...

Bur Oak

Quercus macrocarpa

Deciduous

Other Name: Mossy-cup Oak

Bur Oak Leaf
Bur Oak Leaf
Bur Oak Bark
Bur Oak Bark
Bur Oak Alternate Leaf Pattern
Bur Oak Alternate Leaf Pattern
Bur Oak Fruit
Bur Oak Fruit
 

Leaves: Simple, alternate, blades broader at 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 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.

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

Bark: Dark Brown or yellowish-brown, 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.

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

Fruits: Acorn usually solitary, with or without stalk, the nut ovoid to ellipsoid, dark brown, up to 1 ¾ inches length, the cup covering half to almost all of the nut, hairy, the lower scales long fringed.

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

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

Habitat: Dry ridges to bottomland woods.

Growth Form: Large tree, reaching heights of up to 120 feet. Its trunk is straight, sometimes flaring outward at the base, and reaches a diameter of 5 feet or more. The crown rounded, with stout branches, trunk straight, stout, sometimes slightly buttressed at the base.

Distinguishing Feature: 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.

Source: Mohlenbrock, Robert. Forest Trees of Illinois. Eighth Edition, Illinois Department of Natural Resources, 1996.