You are here
Quercus taxonomy
Quercus stellata Wangenh.
EOL Text
The range of post oak extends from southeastern Massachusetts, Rhode Island, southern Connecticut and extreme southeastern New York (including Long Island); west to southeastern Pennsylvania and West Virginia, central Ohio, southern Indiana, central Illinois, southeastern Iowa and Missouri; south to eastern Kansas, western Oklahoma, northwestern and central Texas; and east to central Florida (10).
It is a large and abundant tree in the southern Coastal Plain, the Piedmont, and the lower slopes of the Appalachians. It is common in the southwest and grows in pure stands in the prairie transition region of central Oklahoma and Texas known as the "Cross Timbers" (2).
Sand post oak (Quercus stellata var. margaretta (Ashe) Sarg.) ranges from southeastern Virginia, west to Missouri and eastern Oklahoma, south to central Texas, and east to central Florida. Delta post oak (Q. stellata var. paludosa Sarg.) is found in bottom lands of the Mississippi River in western Mississippi, southeast Arkansas, and Louisiana, and west to east Texas (10).
-The native range of post oak.
Quercus stellata is often identified by its commonly cross-shaped leaf form, particularly in the eastern part of its range. All individuals and populations do not express this characteristic, however. Moreover, Q . stellata has broad overlap with Q . margaretta and even with some forms of the blackjack oak, Q . marilandica , one of its most common associates. The thick yellowish twigs with indument of stellate hairs and the dense harsh stellate hairs on the abaxial leaf surface are better diagnostic characteristics when variation includes leaf forms that are not obviously cruciform.
Native Americans used Quercus stellata medicinally for indigestion, chronic dysentery, mouth sores, chapped skin, hoarseness, and milky urine, as an antiseptic, and as a wash for fever and chills (D. E. Moerman 1986).
Putative hybrids are known with Quercus marilandica , Q . alba , and various other white oaks. Quercus stellata is also one of the few oaks that appears to produce hybrids with species in the live oak group, although obvious intermediates are rarely encountered. Nothospecies names based on putative hybrids involving Q . stellata include: Q . × stelloides E. J. Palmer (= Q . prinoides × Q . stellata ), Q . × mahloni E. J. Palmer (as Q . sinuata var. breviloba × Q . stellata ), Q . × pseudomargaretta Trelease (= Q . margaretta × Q . stellata ), Q . × sterretti Trelease (= Q . lyrata × Q . stellata ), Q . × macnabiana Sudworth (= Q . sinuata × Q . stellata ), Q . × guadalupensis Sargent (= Q . sinuata × Q . stellata ), Q . × fernowi Trelease (= Q . alba × Q . stellata ), and Q . × bernardensis W. Wolf (= Q . montana × Q . stellata ).
| License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
| Rights holder/Author | eFloras.org Copyright © Missouri Botanical Garden |
| Source | http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233501087 |
Trees , deciduous, to 20(-30) m. Bark light gray, scaly. Twigs yellowish or grayish, (2-)3-5 mm diam., densely stellate-pubescent. Buds reddish brown, ovoid, to 4 mm, apex obtuse or acute, sparsely pubescent. Leaves: petiole 3-15(-30) mm. Leaf blade obovate to narrowly obovate, elliptic or obtriangular, 40-150(-200) × 20-100(-120) mm, rather stiff and hard, base rounded-attenuate to cordate, sometimes cuneate, margins shallowly to deeply lobed, lobes rounded or spatulate, usually distal 2 lobes divergent at right angles to midrib in cruciform pattern, secondary veins 3-5 on each side, apex broadly rounded; surfaces abaxially yellowish green, with crowded yellowish glandular hairs and scattered minute, 6-8-rayed, appressed or semi-appressed stellate hairs, not velvety to touch, adaxially dark or yellowish green, dull or glossy, sparsely stellate, often somewhat sandpapery with harsh hairs. Acorns 1-3, subsessile or on peduncle to 6(-40) mm; cup deeply saucer-shaped, proximally rounded or constricted, 7-12(-18) mm deep × (7-)10-15(-25) mm wide, enclosing 1/4-2/3 nut, scales tightly appressed, finely grayish pubescent; nut light brown, ovoid or globose, 10-20 × 8-12(-20) mm, glabrous or finely puberulent. Cotyledons distinct.
| License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
| Rights holder/Author | eFloras.org Copyright © Missouri Botanical Garden |
| Source | http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233501087 |
Post Oak is native to west-central and southern Illinois, where it is occasional to locally common. Illinois lies along the northern range-limit of this tree. Habitats include upland woodlands, bluffs, upland savannas, wooded slopes, and rocky glades (including sandstone, limestone, and shale glades). Outside of Illinois, Post Oak is also found in dry sandy habitats. Sometimes this tree is cultivated in roadside and urban parks; it is also used for erosion control on exposed stony slopes. Common associates include other upland oaks (Quercus spp.), hickories (Carya spp.), and Eastern Red Cedar (Juniperus virginianus). Post Oak is found in average to high quality habitats where the soil is dry and infertile. It is not competitive with canopy trees that dominant moist fertile sites. Post Oak is able to resprout from its root system after most wildfires.
| License | http://creativecommons.org/licenses/by-nc/3.0/ |
| Rights holder/Author | Copyright © 2002-2014 by Dr. John Hilty |
| Source | http://www.illinoiswildflowers.info/trees/plants/post_oak.html |
Tree with adventitious-bud root crown/root sucker
United States
Rounded National Status Rank: N5 - Secure
| License | http://creativecommons.org/licenses/by-nc/3.0/ |
| Rights holder/Author | NatureServe |
| Source | http://explorer.natureserve.org/servlet/NatureServe?searchName=Quercus+stellata |
More info for the term: mesic
Post oak occurs primarily on dry uplands with southerly or westerly
exposures [47] but may occur on terraces of smaller streams in
well-drained soil [23]. 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 [13,47].
The soils are usually shallow, well-drained, coarse-textured, and
deficient in nutrients and organic matter. It commonly grows in
serpentine soils [56,58]. 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 [25]. 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 [35]. Post
oak grows on drier clayhills that formerly supported longleaf pine
(Pinus palustris) [36].
Post oak occurs on sites too dry for white oak and southern red oak (Q.
falcata) [38], but on slightly more mesic sites than blackjack oak [11]
or eastern redcedar (Juniperus virginiana) [17]. Generally, excessive
soil moisture and inundation cause high mortality or severe stress to
post oak [6]; however, it dominates some flatwoods in southern Indiana
that are moist in the winter [9].
Delta post oak occurs in rich, moist bottomlands, usually on the highest
first bottom ridges and terraces. Soils are fine, sandy loam [13,47].
In addition to those species mentioned in Distribution and Occurrence,
less common overstory associates of post oak include hickories (Carya
spp.), southern red oak, scarlet oak, bluejack oak, live oak, shingle
oak (Q. imbricaria), chinkapin oak (Q. muehlenbergii), bluejack oak,
Shumard oak (Q. shumardii), blackgum (Nyssa sylvatica), sourwood
(Oxydendrum arboreum), red maple (Acer rubrum), winged elm (Ulmus
alata), hackberry (Celtis occidentalis), and dogwood (Cornus spp.) [47].
Overstory associates of Delta post oak include green ash (Fraxinus
pennsylvanica), white ash (F. 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 [46,47].
More info for the terms: fuel, fuel moisture, litter, surface fire, tree, xeric
Post oak is moderately resistant to fire [5]. It is less tolerant than
blackjack oak, about as tolerant as black oak [5,21], and slightly more
tolerant than southern red oak [3]. The basal bark on mature trees is
medium thick, and stands of post oak are moderately open [5]. Smaller
trees are easily killed by fire, but sprout vigorously from the root
collar [55].
If fire is frequent in pine-oak-hickory associations, post oak is an
important constituent because fire provides an opportunity for invasion
by this more fire-resistant oak. If fire is infrequent or absent, post
oak also is absent [28].
In xeric sandhill communities of post oak, blackjack oak, and bluejack
oak, grass and other fuels are rare and fires are only occasional. When
fires do reach these communities, some mature trees may be killed, but
they sprout and the community is maintained [54].
In a study investigating the temperature of a surface fire as it moved
from the surrounding grasslands to the area beneath a single post oak,
the temperature increased sharply from the canopy edge to the midcanopy
position because the increase in fuel load was not accompanied by a
concomitant increase in fuel moisture percentage. The temperature then
decreased from the midcanopy to the base of the tree, despite continued
increase in fuel load and a slight decrease in fuel moisture. This
decline in temperature was presumably caused by the bole of the tree,
which stopped the leading edge of the fire [16].
Under historic FIRE REGIMES, a savanna is maintained because after a hot
surface fire grass grows back faster than the woody sprouts. In the
absence of fire, the woody canopy spreads and the grass dies back. If
fire returns, post oaks are likely to survive because the reduction in
grass fuel results in a much cooler fire. In a fire in central
Oklahoma, all savanna litter burned whereas only 45 percent of the
litter in the adjacent forest burned [24].
Rounded Global Status Rank: G5 - Secure
| License | http://creativecommons.org/licenses/by-nc/3.0/ |
| Rights holder/Author | NatureServe |
| Source | http://explorer.natureserve.org/servlet/NatureServe?searchName=Quercus+stellata |
Fagaceae -- Beech family
John J. Stransky
Post oak (Quercus stellata), sometimes called iron oak, is a medium-sized tree abundant throughout the Southeastern and South Central United States where it forms pure stands in the prairie transition area. This slow-growing oak typically occupies rocky or sandy ridges and dry woodlands with a variety of soils and is considered drought resistant. The wood is very durable in contact with soil and used widely for fenceposts, hence, the name. Due to varying leaf shapes and acorn sizes, several varieties of post oak have been recognized-sand post oak (Q. stellata var. margaretta (Ashe) Sarg.), and Delta post oak (Quercus stellata var. paludosa Sarg.) are included here.