Plant of the Month: October, 1999

by Russell Stevens

Blackjack Oak
Quercus marilandica

Characteristics: Blackjack oak is a medium-sized, deciduous, native tree that can reach a height of sixty feet. It is one of the most common oaks in Oklahoma and one of the dominant Quercus species in the cross timbers region of Oklahoma and Texas. It is an upland oak, most common on sandy soils.

Area of Importance: Most of Oklahoma and Texas, except the panhandles and far western Texas.

Attributes: Deer, quail, turkey, squirrel, raccoon, and other wildlife eat blackjack oak mast (acorns). The tree also provides cover for many wildlife species.

I.D. Tip: Blackjack oak belongs to a group classified as red oaks because its leaf veins continue through the margin (edge) of the leaf and create small, needlelike extensions. This oak, like other species in the group, produces acorns on the previous years' branch growth. It can be identified from a distance by its black bark and has a tendency to retain very tough, dead lower branches that form a drooping canopy. Blackjack oak leaves are usually triangular and are broadest near the tip.

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Hundreds of plants are identified in the Noble Foundation Plant Image Gallery.