Post Oak

Quercus stellata

post_oak_leaf.jpg

Illustration of post oak leaf.
Post oak (Quercus stellata) leaf.
Paul Nelson
Family

Fagaceae (oaks)

Description

Post oak is a small to medium-sized tree with a broad, rounded crown and stout, sometimes contorted branches.

Leaves are alternate, simple, 4–7 inches long, 3–4 inches wide, leathery; with 3–5 lobes, middle lobes squarish, resembling a cross, the end lobe often 3-notched, notches between lobes deep, rounded; upper surface dark green; lower surface paler, with tiny star-shaped hairs.

Bark is gray, irregularly grooved, ridges narrow, rough with platelike scales.

Twigs are stout, densely hairy during most of the season.

Flowers April–May. Male and female flowers are on the same tree; male flowers in drooping catkins, female flowers small and in leaf axils.

Fruits September–October, acorns solitary or paired; nut brown, broadest at the base and tapering to a rounded tip ½–¾ inch long, less than ½ inch wide; cup covering ⅓–½ of the nut, bowl-shaped, hairy on the outside; scales thick, flattened, or somewhat indented, hairy; acorns ripen in autumn of the first year.

Key Identifiers
  • Distinctive cross- or ghost-shaped leaves.
  • Grows in rocky upland woodlands and in flatwoods on broad ridges.
Size

Height: to 70 feet.

post_oak03.jpg

Photo of a post oak tree growing on a lawn.
Post Oak

post_oak_acorn.jpg

Illustration of post oak acorn.
Post Oak Acorn
Post oak (Quercus stellata) acorn.

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Photo looking skyward at post oak branches in autumn.
Post Oak Branches in Fall
Post oak branches are stout and sometimes contorted. Their shapes are easy to see in fall and winter.

Oak _Quercus_spp_Flowers.jpg

Illustration of oak flowers and catkins, male and female.
Oak Flowers
All oak flowers are similar in appearance and emerge in early spring as the new leaves are expanding. Male and female flowers appear on the same tree.
Habitat and conservation

Occurs in mostly dry to rocky upland woodlands and glades; also in flatwoods on broad ridges and lowland terraces where it is typically the dominant tree. A slow-growing, drought-resistant tree, it is difficult to transplant and does better on sites where it is already found growing. Post oaks can live 300 years or more.

image of Post Oak distribution map
Distribution in Missouri

Statewide.

Human connections

The wood is used for railroad ties, furniture, general construction, and fuel. The limbs are sturdy and durable and were favored by pioneers for fence posts, hence the name; this tree played an important role in the success of American pioneers. The bark of most oaks, including this one, has astringent properties, and bark tea was used to treat a number of ailments.

Ecosystem connections

Acorns are eaten by blue jays, woodpeckers, wood ducks, wild turkeys, ruffed grouse, bobwhites, mice, squirrels, raccoons, and deer.