Trees of Iowa: An Interactive Key

Common Post Oak
(Quercus stellata)

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Post Oak is also called Iron Oak, Box White Oak, and Rough Oak. A deciduous shrub or small to medium size tree growing to 40 feet and reaching a maximum of 108 feet with a trunk diameter of 1 to 2 feet - but commonly much smaller. Post Oak can be found in poor dry, rocky, or sandy soil. Its range is from Massachusetts to southern Pennsylvania, west to Iowa in the extreme southeast of the state, and south to northern Florida and Texas.

Hardiness: Varies with the species of oak tree, ranging from zone 3 to zone 9.

Growth Rate:
slow to medium

Mature Shape:
broad, rounded

Varies with species. Often maturing between 50 to 75 feet tall. Capable of growing upwards of 100 feet.

40 to 70 feet. Varies with species

Site Requirements:
Best growth in moist, well-drained soils. Adaptable to adverse soil conditions.

Flowering Dates:

Seed Dispersal Dates:

Seed Bearing Age: 25 Years

Seed Bearing Frequency: Every 2-3 Years

Seed Stratification:

The leaves are a distinctive cross-shape; usually 5-lobed with the two middle lobes opposite and much larger than the other lobes displaying a cross-shape. The leaves are dark green and rough due to the scattered star-shaped hairs, and lighter underneath with yellow fuzz . The twigs are notably thickset also with yellow fuzz, and the bark can appear similar to White Oak; however, Post Oak is darker and has more defined vertical scaly ridges. The acorns are ovoid and 1/2 to 2/3 inches long with a bowl shaped cup.

The wood is heavy, hard and strong and used for posts and railroad ties. Larger trees are sometimes used as lumber and combined with White Oak. Post Oak is reported to hybridize with Southern Live Oak. It is also commonly found with Blackjack Oak and both have similar shaped leaves, but Post Oak has its distinctive yellow fuzz on the twigs and leaves making it easy to tell the two oaks apart.


Click on a thumbnail image below to view a larger picture.
Post Oak Fruit Post Oak Leaves Post Oak Leaves Post Oak Twig Post Oak Fruit Post Oak Leaves Post Oak Seedlings Post Oak Bark