Tree Description:
Usually a medium-sized tree to 35 feet tall with one or more trunks 10" in diameter, but can reach heights of 70 feet on fertile sites.
Range/Site Description:
Found on dry, limestone hills and ridges, and sometimes in the more fertile soils at their base, in Central Texas west to the Edwards Plateau.
Leaf:
Simple, alternate, 3" to 5" long and 2.5" to 3" wide, widest above the middle, divided into 5 to 7 bristle-tipped lobes, with the terminal lobe often 3-lobed and the sinuses usually deep. Leaves have a slender petiole about 1" long, are dark green and shiny above, paler below, and turn deep shades of red in the fall.
Flower:
Male and female flowers borne separately in spring on the same tree; male catkins 1.5" to 3.5" long, yellowish-green, female flowers reddish, about 0.5" long, usually solitary.
Fruit:
An acorn, requiring two years to mature, usually single or in pairs, short-stalked, reddish-brown, pubescent, and often streaked with dark lines; measuring 0.25" to 0.75" long, ovoid, and set in a cup that covers one-quarter to one-half of the fruit.
Bark:
Dark gray to black, smooth at first, then very rough with deep fissures and ridges.
Wood:
Used for fuelwood and posts. Also used as a landscape tree in Central Texas.
Similar Species:
Shumard oak (Quercus shumardii) is very similar and the two species hybridize naturally where they occur together, but Shumard oak acorns are usually larger with a shallow cup and the leaves often have broader lobes.
Interesting Facts:
The spread of oak wilt disease in Central Texas can often be linked to the movement of firewood from infected red oaks. These trees produce "fungal mats" under the bark where certain insects feed; it is these insects that can infect new trees where the firewood has been moved.
