Overcup oak (Quercus lyrata), also called swamp post oak, swamp white oak, and water white oak, is quite tolerant of flooding and grows slowly on poorly drained flood plains and swamp lands of the Southeastern United States. It may take 30 years before overcup oak produces acorns. Wildlife use them as food. The quality of the lumber varies greatly and the wood may check and warp during seasoning. It is cut and sold as white oak.
The utility of overcup oak varies extremely with site, fire damage, and degree of insect and decay defect. Logs harvested from the best overcup oak sites may be used for lumber and sometimes tight cooperage, but the wood is frequently worthless for factory lumber and other quality products. Moreover, checking during seasoning often prevents general use even as ties and timbers. The species is sometimes used for ornamental purposes. The trees provide habitat and the acorns supply mast for wildlife.
Forestryimages.org provides several images of parts of overcup oak. The tree is a hardwood and the lineal taxonomy is Magnoliopsida > Fagales > Fagaceae > Quercus lyrata. Overcup oak is also commonly called swamp post oak, swamp white oak, and water white oak.
3. The Range of Overcup Oak
Overcup oak inhabits the wetter sites in bottom lands of the Coastal Plain from Delaware and Maryland south to Georgia and northwestern Florida; west to eastern Texas. It grows northward in the Mississippi Valley to southeastern Oklahoma, southeastern Missouri, southern Illinois, southwestern Indiana, and western Kentucky.
Leaf: Alternate, simple, 6 to 10 inches long, roughly oblong in shape with a highly variable margin that has 5 to 9 lobes with irregular sinuses. The underside is white and pubescent.
Twig: Slender and gray, glabrous - very closely resembling white oak. Buds are small, ovoid and light chestnut brown in color; end buds are clustered.
DeSelm and Clebsch reported that mature overcup oak trees are somewhat resistant to direct mortality from fire, but barely survived two to five prescribed fires between 1964 and 1988. In overcup oak, even minor injuries from fire can create avenues of infection for heart rots, which can cause decadence and/or mortality years later.