October, 2003 AS
October, 2003 AS
October, 2003 AS
October, 2003 AS
October, 2003 AS
October, 2003 NJ
October, 2003 NJ
October, 2003 NJ
October, 2003 NJ
October, 2003 NJ
Leaf: 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 to7 lobes, the lobes not bristle-tipped, dark green, lustrous, and smooth or slightly hairy on the upper surface, paler and softly hairy on the lower surface, up to14 inches (36 cm) long and 7 inches (18 cm) wide; leaf stalks up to 1 inch (2.5 cm) long, stout, smooth or finely hairy; leaves turning a dull yellow-brown in autumn.
Flower: Staminate and pistillate born separately, but on the same tree; appearing as the leaves begin to unfold; each flower tiny and without petals; the staminate in slender, drooping, yellowish catkins; the pistillate few in a group, with red stigmas; flowering on the current year's branches in May to June.
Fruit: Acorn usually solitary, with or without a stalk, the nut ovoid to ellipsoid, dark brown, up to 1 3/4 inches (4.5 cm) long, the cup covering 1/2 to nearly all the nut, hairy, the lowermost scales long-fringed; fruit ripening in 1 year and sometimes germinating soon after falling to the ground.
Twig: Stout, dark brown, often with corky ridges; pith star-shaped in cross-section; leaf scars alternate but clustered near the tip, half-rounded, slightly elevated, with several bundle traces; buds rounded or slightly pointed at the tip, yellowish-brown to reddish-brown, finely hairy.
Bark: Dark brown or yellow-brown, rather deeply furrowed.
Form: Large tree up to 120
feet (36 m) tall, often wider than tall; trunk diameter up to 5 feet (1.5 m); crown
rounded, with stout branches; trunk straight, stout, sometimes slightly
buttressed at the base.
Discussion
The word Quercus is Latin for oak, and the name of the tree is bur oak, so that part is self-explanatory. The word macrocarpa, in Latin, means large fruit or acorn. The bur oak has the largest acorns of our native oaks.
The bur oak is very important to wildlife, providing food for a wide variety of species, including deer, squirrels, ground squirrels, rabbits, wood ducks, turkeys, and rodents. The large size of the acorns prevents most birds from eating the fruits. Bur oak also provides animals with shelter, branches for roosting, and nesting materials.
Bur oak trees are among the most drought-tolerant trees in the United States. This characteristic made bur oak an important tree of prairie edges, offering shelter and acorns where other trees failed. In the dryer parts of its range (as in the Great Plains), bur oak grows along streams, though not where the soil is too wet. Older bur oak trees have very thick bark that protects the tree from fire. Older bur oaks are also quite disease-resistant, tolerant of low-mineral soils and fairly acidic conditions. They can survive for hundreds of years.
Native Americans of the vast interior grasslands used bur oak acorns, which are rich in fat, proteins, and starch, to supplement their diets. Bur oak was the only type available in some areas where rainfall was relatively limited. Bur oak acorns do not store well because they will sprout after falling to the ground. Native Americans roasted or boiled the acorns to remove some of the bitter tannins. They mixed ground acorns with fat to be made into breads or softer foods.
This species of oak was widely planted in shelterbelts on western farmsteads due to its drought-tolerance.
The wood of the bur oak was once among the most important woods in the U.S., though bur oak is not commercially important now, having been overharvested in the past. The wood is hard, tough, close-grained, and moderately heavy. Bur oak lumber was combined with and sold as white oak or red oak. It was widely used for flooring, furniture, decks, cabinets, and interior finishes.
The bur oak makes a very nice shade tree but is very rarely planted in urban, inner-city areas. The young trees are difficult to transplant and are slow growing. The mature tree has an extensive root system, so that keeps it from being transplanted. This tree is meant more for larger areas such as parks, campuses, and golf courses.
Distinguishing Characteristics
Bur oaks are distinguished from other oaks by
their leaves which are very broad in the upper half with a pair of deep sinuses a little below
the middle and by the large, fringed cups of the acorns.
Distribution
Bur oak is found from Vermont across to North Dakota, south to Texas, east to Arkansas, Tennessee, and Maryland, inhabiting dry ridges to bottomland woods.
Images
Click each small picture to see a larger image.
|
|
October, 2003 AS |
|
|
|
|
|
|
|
|
|
|
|
Location
N 39.26876° W -89.89079°
91 paces down the west of end of the fitness trail (west of the southernmost
soccer field), off the east edge of the path, in Loveless Park, South Locust
Street, Carlinville,
Macoupin County, IL.
Copyright
Photos © 2003 Nic Johnson and Adam Strope, Carlinville High School, linke@carlinvilleschools.net
References
Mohlenbrock, Robert H. 1996. Forest trees of Illinois. 8th ed. Illinois Dept. of Conservation Publications, Springfield. 331 pp.
Petrides, George A. 1988. A field guide to eastern trees. Houghton
Mifflin Company, Boston. 272 pp.
Paul S. Johnson. USDA Forest Service- Northeastern Area State & Private Forestry
http://www.na.fs.fed.us/spfo/pubs/silvics_manual/volume_2/quercus/macrocarpa.htm
Iowa State University, Biology Department
http://project.bio.iastate.edu/trees/campustrees/QueMacro/QMacr_uses.html
Forestworld- The Sustainable Forest Products Resourse
Athenic Systems- Tree Guide
http://www.treeguide.com/Species.asp?Region=NorthAmerican&SpeciesID=861
Botanical Word Meanings and Name Derivations and Southern
California Wildflowers
http://www.calflora.net/botanicalnames/pageQ-S.html