Quercus Virginiana - Description

Description

Although typically evergreen, the leaves persisting until the time growth resumes in spring, a live oak's defoliation may occur sooner in marginal climates or in dry or cold winters. The bark is dark, thick, and furrowed longitudinally. The leaves are stiff and leathery, with the tops shiny dark green and the bottoms pale gray and very tightly tomentose, simple and typically flattish with bony-opaque margins, with a length of .75 - 6 inches (2 – 15 cm) and a width of .4 - 2 inches (1 – 5 cm), borne alternately. The male flowers are green hanging catkins with lengths of 3 - 4 inches (7.5 –10 cm). The acorns are small, .4 - 1 inch (1 - 2.5 cm), oblong in shape (ovoid or oblong-ellipsoid), shiny and tan-brown to nearly black, often black at the tips, and borne singly or in clusters.

Depending on the growing conditions, live oaks vary from the shrubby to large and spreading: typical open-grown trees reach 15 meters (45 feet) in height, but may span nearly 50 meters. Their lower limbs often sweep down towards the ground before curving up again. They can grow at severe angles, and Native Americans used to bend saplings over so that they would grow at extreme angles, to serve as trail markers.

The branches frequently support other plant species such as rounded clumps of ball moss, thick drapings of Spanish moss, resurrection fern, and parasitic mistletoe.

The southern live oak has a deep tap-root that anchors it when young and eventually develops into an extensive and widespread root system. This, along with its low center of gravity and other factors, makes the southern live oak extremely resistant to strong sustained winds, such as those seen in hurricanes.

The southern live oak grows in a wide variety of sites but is not fire-tolerant and occurs most any place free from fire that is not too wet. They can withstand occasional floods and hurricanes, and are resistant to salt spray and moderate soil salinity. They tend to survive fire, because often a fire will not reach their crowns. Even if a tree is burned, its crowns and roots usually survive the fire and sprout vigorously. Furthermore, live oak forests discourage entry of fire from adjacent communities because they provide dense cover that discourages the growth of a flammable understory. Although they grow best in well-drained sandy soils and loams, they will also grow in clay. Live oaks are also surprisingly hardy. Those of southern provenance can easily be grown in USDA zone 7 and the Texas live oak (Quercus virginiana var. fusiformis), having the same evergreen foliage as the southern variety, can be grown with success in areas as cold as zone 6. Even with significant winter leaf burn, these trees can make a strong comeback during the growing season in more northerly areas, such New Jersey, southern Ohio, and southern Connecticut.

Among the animals for which live oak acorns are an important food source are the bobwhite quail, the threatened Florida scrub jay, the wood duck, yellow-bellied sapsucker, wild turkey, black bear, various species of squirrel, and the white-tailed deer. The tree crown is very dense, making it valuable for shade, and the species provides nest sites for many other species.

The live oak is the larval host plant for the hairstreak butterfly and oakworm moth.