This tree is typically 60-80' tall at maturity, consisting of a single
trunk about 1½-3' across and a pyramidal or ovoid crown with ascending
to widely spreading branches. The crown is somewhat open and
irregular and the branches are often crooked. Trunk bark is blackish
gray or brownish gray; it is shallowly to moderately furrowed,
rough-textured, and often dividing into irregular rectangular plates.
is more gray and smooth, while the rather stout twigs are gray to brown
with white lenticels. The terminal buds of twigs are pubescent and
either tan or gray. Alternate leaves occur along the twigs. Individual
are 3-9" long and 2½-6" across; they are ovate to obovate in outline
and pinnatifid, dividing into 5-7 (less often 9) major lobes and some
smaller secondary lobes. The lobes are pointed and they have short
bristles at their tips; the sinuses between the lobes are concave.
Leaves exposed to sunlight tend to have deeper lobes than those
growing in the shade. The upper leaf surface is dark green, hairless,
and glossy, while the lower surface is pale to medium green and dull.
In the typical variety of Black Oak, the lower surface of mature leaves
is hairless, except for patches of tan or reddish brown downy hairs
near the forks of the major veins. In a more southern variety (var.
) of Black Oak, mature leaves have a scurfy
canescence across the entire lower surface. The petioles are 1-3" long,
light green to yellow, and glabrous or canescent; they often bend from
the weight of the leaves.
Black Oak is monoecious, producing male
(staminate) and female (pistillate) flowers on the same tree. The
inflorescence of male flowers consists of a cluster of drooping
yellowish catkins about 4-6" long. The central stalks of the catkins
pubescent. The female inflorescence consists of a short
spike of 1-4 reddish female flowers. Each female flower
consists of an ovoid ovary with a conspicuous tripartite style; the
surrounded by floral bracts (phyllaries) that are scaly and pubescent.
blooming period occurs from mid- to late spring. The flowers are
wind-pollinated. The catkins of male flowers soon wither away,
while fertile female flowers are replaced by acorns. These acorns
require 2 years to fully develop; at maturity, they are ½-¾" long and
ovoid-globoid in shape. Each acorn has a cup at its apex that extends
downward to about 1/2 of its length; the relatively loose scales of the
become smaller as they approach its lower rim. Along the lower rim of
the cup, the scales form a short fringe. Each acorn contains a single
large seed. The woody
root system produces a deep taproot and lateral roots.
This tree reproduces by reseeding itself. The deciduous leaves become
dull red, yellow, or brown during the fall.
preference is full or partial sun and mesic to dry conditions. Black
Oak adapts to many types of soil, including those that contain deep
loam, clay, rocky material, or sand. This tree begins the
production of acorns after 20 years, and its longevity is not
years. An infestation of oak wilt disease can be fatal.
The typical variety of the native Black Oak is a
that is found in every county of Illinois (see Distribution
other variety of Black Oak (var.
), is restricted to a few
southern counties within the state, where it is uncommon. This tree is
native to the state. Habitats
include upland woodlands, rocky open woodlands,
sandy woodlands, upland savannas and sandy savannas, stabilized sand
wooded bluffs and rocky ridges, sandstone and limestone glades, and
woodland borders. Sometimes Black Oak is the dominant canopy tree in
sandy woodlands, sandy savannas, and upland rocky areas. It is rarely
cultivated as a landscape tree.
Like other Quercus spp.
(oaks), Black Oak is beneficial to many kinds of wildlife. The
foliage is eaten by the
caterpillars of several butterflies: Calycopis cecrops
(Banded Hairstreak), Satyrium
(Edward's Hairstreak), Satyrium liparops strigosum
Hairstreak), and Parrhasius
(White-M Hairstreak); the foliage
is also eaten by the caterpillars of a skipper, Erynnis brizo
(Sleepy Duskywing). The
caterpillars of numerous moths are known to feed on oaks; the
some of these species. Another major group
of insect feeders are the larvae of wood-boring beetles (Buprestidae,
Cerambycidae, etc.); the Wood-Boring Beetle Table
many of these species. Other insect feeders include leaf beetles (Babia
the larvae of some weevils (Attelabus
plant bugs (Ceratocapsus
), the Oak Lace Bug (Corythucha arcuata
, & others),
(Oak Treehopper) and other treehoppers (mainly
& Telamona spp.
the larvae of several gall wasps
), the larvae of Caliroa
(Bird-Winged Grasshopper), and
The acorns of oaks are
an important food source for many vertebrate animals. The Bird
lists several upland gamebirds and songbirds that feed on acorns;
mammals that consume acorns include the Black Bear, Opossum, Raccoon,
Southern Flying Squirrel, Fox Squirrel, Gray Squirrel, Red Squirrel,
Eastern Chipmunk, White-Footed Mouse, and White-Tailed Deer.
White-Tailed Deer also browse on the twigs and foliage, while the
Cottontail Rabbit gnaws on the bark of saplings and foliage of
seedlings. Many birds, tree squirrels, bats, and other wildlife find
shelter within the cavities of oaks, and many birds favor oak trees as
providers of nesting habitat and feeding sites (e.g., warblers
other insectivorous birds are attracted by the many insects that feed
A sandy area near Lake Michigan at
State Park in NW Indiana.
Black Oak is a member of the "red oak group" that has leaves with
pointed bristly lobes and acorns that require 2 years to mature. The
shape of its leaves are more variable than most oaks. At one time, the
yellow-orange inner bark was used heavily in the leather tanning
it also produced an important yellow dye. Like other oaks, the heavy
wood of Black Oak is hard and strong, therefore it is used to make
wooden furniture, floors, interior finishing, barrels, railroad ties,
and other wooden products. Black Oak can be distinguished from other
oaks by the patches of tan or reddish brown hair that occur near the
forks of the veins on the lower sides of its leaves (for the typical
variety), the relatively long and slightly fringed cups of its
acorns, and its often yellowish petioles. A southern variety of Black
Oak (var. missouriensis
is slightly different by having a
scurfy pubescence on the lower side of its leaves.