post oak (Quercus stellata)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

COMMON NAMES:
post oak
Delta post oak
iron oak
cross oak
dwarf post oak
runner oak
scrubby post oak
Boynton post oak
Drummond post oak
bottomland post oak
bottom-land post oak
Mississippi Valley oak
and yellow oak

 

SCIENTIFIC SYNONYMS:
Quercus boyntonii Beadle
Quercus mississippiensis Ashe
Quercus similis Ashe
Quercus drummondii Liebm.
Quercus stellata var. boyntonii (Beadle) Sarg.
Quercus stellata var. mississippiensis (Ashe) Little
Quercus stellata var. similis (Ashe) Sudw.

 

CONFIRMATION STATUS: Confirmed.

 

TAXONOMY: The currently accepted scientific name of post oak is
Quercus stellata Wangenh. Post oak has been placed within the white oak
group. The following varieties are recognized: 1) Quercus stellata var.
paludosa Sarg. (Delta post oak) and 2) Quercus stellata var. stellata (post
oak).

 

Identification of post oak is difficult because of its many growth forms. At
times, local populations have been given species or varietal status. A dwarf
post oak that grows near Lufkin, Texas, is called Boynton post oak (Quercus
boyntonii). Drummond post oak, which grows in deep sands of Texas, is
thought to be a hybrid between post oak and sand post oak (Quercus
margaretta). It has also been considered a species (Quercus drummondii)
by some authors. Post oak hybridizes with the following species: white oak,
swamp white oak, Durand oak, Havard oak, overcup oak, bur oak, dwarf
live oak, Mohr oak, dwarf chinkapin oak, chestnut oak, and live oak.

 

NATIVE STATUS: Native, United States.

 

GENERAL BOTANICAL CHARACTERISTICS: Post oak is a long-
lived, native, deciduous tree with a crown of horizontal branches. The
varieties are distinguished by leaf shape, acorn size, growth form, and site
preferences. The typical variety usually grows 50 to 60 feet (15.2-18.3 m)
in height and 12 to 24 inches (30-61 cm) in d.b.h. It rarely exceeds 100 feet
(30.5 m) in height and 48 inches (122 cm) in d.b.h. In the drier areas
of its range (Texas), post oak is typically only 30 to 40 feet (9-12 m) tall and
15 to 18 inches (38-46 cm) in d.b.h. Post oak is slow growing and lives 300
to 400 years. Seedlings have especially thick taproots. Most roots develop
above underlying clay horizons. Delta post oak is generally larger than the
typical variety, growing to about 100 feet (30 m) in height.

 

REGENERATION PROCESSES: Post oak is monoecious. Seed
production begins when the tree is about 25 years old. Good crops
occur at 2- to 3-year intervals. Post oak does not produce as many
acorns as white oak, blackjack oak, black oak (Quercus velutina), or
scarlet oak (Quercus coccinea). Acorns germinate in autumn soon after
falling. The ideal seedbed is moist soil covered with 1 inch (2.5 cm) or
more of leaf litter. Height and diameter growth are slow; 10 year d.b.h.
growth generally averages less than 2 inches (5 cm). Post oak usually
grows more slowly than any associated trees except blackjack oak.
Seedlings are resistant to drought but not to flooding. Post oak seedlings
were more drought tolerant than white oak, black oak, or northern red
oak (Quercus rubra), primarily because of greater drought tolerance of leaf
and root cells.

 

Trees up to 10 inches (25 cm) in d.b.h. sprout prolifically from the root
crown after being top-killed. Post oak tends to have fewer sprouts per
clump than black, chestnut, white, or scarlet oaks. Post oak sprouts grow
faster than seedlings. Post oak often occurs in small clusters of two to six
trees; these clusters may represent a single individual because the species
occasionally reproduces vegetatively from roots, especially under moisture
stress.

 

SITE CHARACTERISTICS: Post oak occurs primarily on dry uplands
with southerly or westerly exposures but may occur on terraces of smaller
streams in well-drained soil. Post oak is common to about 2,950 feet
(900 m) in elevation throughout its range and rare to about 4,920 feet
(1,500 m) in the southern Appalachian Mountains. The soils are usually
shallow, well-drained, coarse-textured, and deficient in nutrients and
organic matter. Post oak is often restricted to sites where a heavy clay
subsurface layer is within 1 foot (0.3 m) of the surface or bedrock is within
2 to 3 feet (0.6-0.9 m) of the surface. It may grow in shallow sand overlying
beds of clay or gravel, but the typical variety of post oak appears to be
restricted from deep sands. Post oak grows on drier clayhills that formerly
supported longleaf pine (Pinus palustris). Post oak occurs on sites too dry
for white oak and southern red oak (Quercus falcata), but on slightly more
mesic sites than blackjack oak or eastern redcedar (Juniperus virginiana).
Generally, excessive soil moisture and inundation cause high mortality or
severe stress to post oak. Delta post oak occurs in rich, moist bottomlands,
usually on the highest first bottom ridges and terraces. Soils are fine, sandy
loam.

 

Common overstory associates of post oak include hickories (Carya
spp.), southern red oak, scarlet oak, bluejack oak, live oak, shingle oak
(Quercus imbricaria), chinkapin oak (Quercus muehlenbergii), bluejack
oak, Shumard oak (Quercus shumardii), blackgum (Nyssa sylvatica),
sourwood (Oxydendrum arboreum), red maple (Acer rubrum), winged
elm (Ulmus alata), hackberry (Celtis occidentalis), and dogwood (Cornus
spp.). Overstory associates of Delta post oak include green ash (Fraxinus
pennsylvanica), white ash (Fraxinus americana), white oak, water oak,
blackgum, sweetgum (Liquidambar styraciflua), American elm (Ulmus
americana), winged elm, American hornbeam (Carpinus caroliniana),
American sycamore (Platanus occidentalis), black willow (Salix nigra),
and hickories.

 

SUCCESSIONAL STATUS: Post oak is intolerant of shade and
competition. Because of slow growth it is often overtopped by other
species, including most oaks. It persists and becomes dominant on poor
sites because of its drought resistance. Delta post oak is moderately
intolerant of shade. Post oak is common in the understory of pine
(Pinus spp.) -hardwood forests. In the absence of fire, post oak may
become dominant depending on site conditions and competition from
associated species.

 

SEASONAL DEVELOPMENT: Post oak flowers from March to June
depending on elevation and latitude. Flowers appear at the same time as
leaves. Acorns mature in one growing season and drop soon after ripening
from September through November. Acorns exhibit no dormancy and
germinate soon after dropping.

 

GENERAL DISTRIBUTION: Post oak is widespread in the eastern
and central United States from southeastern Massachusetts, Rhode Island,
southern Connecticut, and extreme southeastern New York; south to
central Florida; and west to southeastern Kansas, western Oklahoma,
and central Texas. In the Midwest, it grows as far north as southeastern
Iowa, central Illinois, and southern Indiana. It is an abundant tree in coastal
plains and the Piedmont and extends into the lower slopes of the Appalachian Mountains. Delta post oak occurs in bottomlands in eastern Texas and in
the Mississippi River valley in western Mississippi, southeastern Arkansas,
and Louisiana.

 

SKY MEADOWS DISTRIBUTION:

 

Tree specimens can be found on trails marked in red.

 

       Bleak House
       Appalachian Trail/Old Trail
       South Ridge/North Ridge
       Gap Run
       Snowden
       Woodpecker Lane

       Sherman's Mill
       Rolling Meadows/ Lost Mountain
       Fish Pond

 

HABITAT TYPES AND PLANT COMMUNITIES: Post oak occurs
as a dominant tree in savannas and in forests adjacent to grasslands. It
forms pure stands or mixed stands with blackjack oak (Quercus mariland-

ica) in the prairie transition area of central Oklahoma and Texas, where

the eastern deciduous forests grade into the drier western grasslands.

 

IMPORTANCE AND USES: Post oak provides cover and habitat for
birds and mammals. Cavities provide nest and den sites, and leaves are
used for nest construction. The acorns are an important food source for
wildlife including white-tailed deer, wild turkey, and squirrels and other
rodents.

 

The tannin in leaves, buds, and acorns is toxic to sheep, cattle, and goats.

Among 12 southeastern oak species, post oak ranked third in preference to
the fox squirrel. Acorns of white oak group species are generally more
palatable than black oak group acorns.

 

Post oak is planted for soil stabilization on dry, sloping, stony sites, which
are unsuitable for other species.

 

Post oak is not a preferred timber species. It is difficult to grade because of
insect damage, and natural pruning and growth are slow. The wood is very
durable and classified as moderately to very resistant to decay. It is used
for railroad ties, mine timbers, flooring, siding, lathing, planks, construction
timbers, and fence posts (hence its name). Wood of Delta post oak is of
better quality than that of the typical variety, but it has a distinct yellow-
tan cast which requires separate handling as veneer. Otherwise, Delta post
oak wood has broad utility.

 

Post oak is used as a shade tree and its bark is used for decorative and
protective mulch in landscaping.

 

 

Back to Inventory of Tree Families and Species