Leaf: Alternate, simple, elliptical overall; blades divided more than half-way to the middle into 5 to 7 deep bristle-tipped lobes, each lobe with a few bristle-tipped teeth and wide, rounded sinuses; base short-pointed; dark green, shiny and more or less smooth on the upper surface; paler and slightly shiny with tufts of hairs in the vein angles along the midvein on the lower surface; up to 7 inches long and 4 inches broad; leafstalk up to 2 inches long, slender, usually smooth; turning red or brown in fall, persisting into the winter.
Flower: Male and female 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 to 3 on spikes.
Fruit: Acorns 1 to 4 together, with or without stalks; the nut nearly round, up to 1/2 inch across, pale brown, frequently with darker lines, enclosed less than 1/4 by the cup; the cup thin, saucer-shaped, reddish-brown, finely hairy; maturing in the second year, dispersing September through December.
Twig: Slender, smooth, lustrous, 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; multiple terminal buds that are small, pointed, and chestnut brown.
Bark: Light to dark grayish-brown, hard; remaining smooth for many years, eventually developing thin ridges and furrows, fissuring into short, broad, scaly ridges.
Form: Medium tree up to 75 feet tall; trunk diameter usually less than 3 feet; crown narrowly rounded, pyramidal, or oblong, but with the lower branches drooping and middle branches growing at right angles; trunk straight with pin-like stubs developing rather low on the trunk; branches studded with branchlets giving a spiny appearance.
Discussion
Pin oaks are commonly used in street and ornamental planting. The pin oak transplants easily, grows quickly, and requires little care. Coupled with its qualities of producing shade and having a fairly compact form, these features made the pin oak one of the most commonly planted trees. However, it doesn't do well in highly alkaline soils, developing chlorosis which may lead to the tree's decline and death. Unfortunately, concrete sidewalks, brick foundations, and paved roads contribute to the soil's alkalinity, so many pin oaks grow well for 20 to 30 years and then develop chlorosis.
The wood is hard, heavy, and coarse-grained, and has been used for construction, fuel, and fence posts.
Pin oaks are
partial to moist soil as found in bottomlands, growing along streams
with such trees as the silver maple, American elm, sycamore, and sweet gum.
The tree's Latin name palustris means "marshes."
Distinguishing Characteristics
The
pin oak is recognized by its drooping lower branches, pyramidal shape, and small acorns.
Distribution
Massachusetts across to southeastern Iowa, south to northeastern Oklahoma, east to northern Virginia.
Images
Click each small picture to see a larger image.
Location
N 39.27763º W -89.87921°
South side of the 200 Block of East 2nd South, Carlinville, Macoupin County, IL.
Copyright
Photos © 2002 William Aper and Rodney E. Johnson, Carlinville High School, linke@carlinvilleschools.net
References
Robert H. Mohlenbrock, Forest Trees of Illinois, 1996, Illinois Department of Natural Resources.
Elbert L. Little, Field Guide to Trees: Eastern Region, 1980, Alfred A. Knopf.
Eleanor Lawrence and Cecilia Fitzsimons, Trees, 1985, Longmeadow Press.
George A. Petrides, Trees and Shrubs, 1986, Houghton Mifflin Company.
George A. Petrides, Eastern Trees, 1988, Houghton Mifflin Company.
Herbert S. Zim and Alexander C. Martin, Trees, 1956, Western Publishing Company, Inc.
William C. Grimm, Familiar Trees of America, 1967, Harper & Row.
G. H. Collingwood and Warren D. Brush, Knowing Your Trees, 1964, The American Forestry Association.
Virginia Tech Dendrology Program
http://www.cnr.vt.edu/dendro/dendrology/syllabus/qpalustris.htm
Iowa State University Biology Department
http://project.bio.iastate.edu/trees/campustrees/QuePalust/QPal_text.html
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