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White Oak - Quercus alba L.
Family: Fagaceae - Beeches, Chinkapins and Oaks
White oak is an outstanding tree among trees and is widespread across
eastern North America.
The Morton Arboretum is home to Illinois'
Millennium Landmark Tree, a white oak. |
There are about four hundred species in the oak genus (Quercus)
worldwide. Oak trees are majestic beauties and symbols of
strength in many cultures. The oak is the national tree of
not only the United States, but of England and Germany as
well.
White oak grows under a wide variety of climatic conditions,
and a great variety of soil types. It is a large, long-lived
tree often 80 to 100 feet in height and 36 to 48 inches in
trunk diameter. Individual trees 150 feet high, 96 inches
diameter and 600 years old have been recorded. In the open,
white oak is characterized by a short stocky bole with a
wide spreading rugged crown. In the forest, white oaks
develop a tall straight trunk with a compact crown. |
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This White Oak at The Morton Arboretum is Illinois' Millennium
Landmark Tree.
It predates Illinois' 1818 statehood.
An oak "hedgehog" gall on a white oak leaf. This growth is induced
by a small cynipid gall wasp whose larva develops inside. |
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Several insects attack white oak
trees. They are usually not important but may become
epidemic and kill weakened trees. Economically, the most
important are the wood borers. These may damage the wood
of standing trees and cause log and lumber defects.
White oak is attacked by several leaf eaters including
the gypsy moth (Lymantria dispar), orange-striped
oakworm (Anisota senatoria), variable oakleaf
caterpillar (Heterocampa manteo), several oak leaf tiers
and walking stick. The Cynipid wasps cause galls to
develop on the leaves, in the acorn or on the cup.
White oak also hosts various scale
insects, gall-forming insects, and twig
pruners, but most of these are of minor
importance. White oak acorns are commonly
attacked by insects, in some cases affecting
half the total acorn crop. Weevils of the
genera Curculio and Conotrachelus cause most
acorn damage. Light acorn crops usually are
more heavily infested than heavy ones. Two
moths damage acorns, the filbert worm
(Melissopus latiferreanus) and Valentinia
glandulella. |
This white oak is 65 years old and approximately 70 feet tall. |
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White oak usually becomes dominant in the
stand because of its ability to persist for long periods of
time in the understory, its ability to respond well after
release, and its great longevity. When associated with other
oaks and hickory in the central and southern hardwood
forests, white oak is considered a climax tree. On good
sites in the north, it is usually succeeded by sugar maple.
Acorns are a valuable though inconsistent source of wildlife
food. More than 180 different kinds of birds and mammals use
oak acorns as food; among them are squirrels, blue jays,
crows, redheaded woodpeckers, deer, turkey, quail, mice,
chipmunks, ducks, and raccoons. White oak twigs and foliage
are browsed by deer especially in clearcuts less than 6
years old. White oak is sometimes planted as an ornamental
tree because of its broad round crown, dense foliage, and
purplish-red to violet purple fall coloration. It is less
favored than red oak because it is difficult to transplant
and has a slow growth rate.
-- United States Department of Agriculture NRCS Plant Fact Sheet |
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