Leaf: alternate, simple, 3-5" (7.5-13 cm) long, 2-4" (5-10 cm) wide. Eliptical: 5-7 deep lobes nearly to midvein with few bristle-tipped teeth and wide rounded sinuses; base short-pointed. Shiny dark green above, light green and slightly shiny with tufts of hairs in vein angles along midvein beneath; turning red or brown in fall.
Flower: staminate and pistillate borne separately, but on the same tree, appearing when the leaves begin to unfold, minute, without petals, the staminate in slender, drooping catkins, the pistillate in groups of 1-3.
Fruit: acorns; 1-4 together, with or without stalks, 1/2" (12 mm) long and broad; nearly round; becoming brown; 1/4-1/3 enclosed by thin saucer-shaped cup tapering to base; maturing second year.
Twig: slender, smooth, reddish-brown to dark gray, pith star-shaped in cross-section; leaf scars alternate but crowded near the tip, half-round, usually slightly elevated, with several bundle traces.
Bark: dark gray; hard; smooth, becoming fissured into short, broad, scaly ridges.
Form: Medium tree up to 75 feet tall; straight-trunked with spreading to horizontal branches, and a broadly conical crown.
Habitat: In nearly pure stands on poorly drained, wet sites, including clay soils on level uplands; less common on deep, well-drained bottomland soils.
Range: Extreme southern Ontario to Vermont, south to central North Carolina, west to northeast Oklahoma, and north to southern Iowa; to 1000' (305 m).
Location: on Bunker Hill High School campus, west of tennis courts.
Latitude: 39o0248N
Longitude: 089o57.66W
The pin oak is a popular graceful lawn tree with regular compact form and fine-textured foliage. Pin oak is hardy and easily transplanted because the shallow fibrous root system lacks tap roots.
© Community Unit School District #8, Bunker Hill
504 E. Warren, Bunker Hill, IL 62014
References:
Little, Elbert L. Field Guide to Trees: Eastern Region. New York, NY: Alfred A. Knopf Inc., 1980.
Mohlenbrock, Robert H. Forest Trees of Illinois. Springfield, IL: 1992