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Trees of Iowa: An Interactive Key

Blackjack Oak
(Quercus marilandica)




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The Blackjack Oak is also known as the Jack Oak, Black Oak, and Barren Oak. A small deciduous tree that grows 20 to 30 feet (maximum 90 feet) with a trunk diameter of 1 foot or less. It is similar to the Post Oak which also grows with Blackjack Oak, but the leaf lobes are more pronounced and not bristle-tipped.

The leaves are 4 to 8 inches long, 3-lobed, bristle-tipped, taper to a rounded base, obovate in outline, thick petioles less than 1/2 inch long, top is dark yellow-green, beneath is paler with a tawny colored down.



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

Growth Rate:
slow to medium

Mature Shape:
broad, rounded

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

Width:
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:

Seed Bearing Frequency:

Seed Stratification:

Acorns are 3/4 inch long, with a shallow cup shaped like a goblet, and somewhat hairy. The nut is ovoid shape, yellow-brown, and striated. The twigs are thick, dark red-brown and hairy, and the trunk is almost all black with deep grooves and scaly plates.

The Blackjack Oak is known for growing in barren, dry, sandy, or clay soils. Its range extends from southeastern New York to southern Michigan and Nebraska, south to central Florida and eastern Texas. Blackjack Oak can be found in the upland woods of northeast Iowa.

 

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Blackjack Oak Leaves Blackjack Oak Leaves Blackjack Oak Bark Blackjack Oak Form Blackjack Oak Fruit Blackjack Oak Leaves