The white oak (Quercus alba) is a deciduous large native tree common in the eastern and central part of North America and is an important source of hardwood timber. Pyramidal shaped when young, the White Oak can grow into a majestic tree with wide branches and a open crown. Although it is called a White oak, the bark of the tree is usually light ash grey and becomes scaly with age, often with a reddish cast. Twigs are fairly tout, green to reddish-green when young (becoming red, then gray with age). The leaves have 7 to 9 lobes and are more deeply-cut than those of the English oak. They usually turn red or brown in the fall. Some dead leaves may remain on the tree throughout winter. Acorns are ¾” with a short stalk and shallow cap. White oak is the state tree of Connecticut, Illinois and Maryland. White oak wood has been important commercially in making barrels and ship building. Because white oak hybridizes readily with compatible species, variants are common and identification out of context can be tricky. Introduced to Europe in 1724. Like all Fagales the tree retains many leaves during the winter. The Latin name for “glans” is acorn taken from the morphologically similarity to the tip of the mammalian penis also called a ‘glans’. Quercus is the Latin name for “oak”. The species epithet refers to the tree’s white, light ash-gray bark.
The Mercer White Oak was a large oak tree located on the Princeton Battlefield. During the Battle of Princeton, general Mercer was stabbed by an English soldier’s bayonet near the white oak. A silhouette of the Mercer Oak is on the seal of Mercer County and the town of Princeton. In March 2000, strong winds brought down this 300-year-old tree. Luckily, clones of the Mercer Oak were collected in the 1970s and a white oak in Marquand Park was grown from on of these clones.
Common name: White Oak, Eastern White Oak, Stave Oak
Scientific Name (family and order): Quercus alba L. (Fagaceae, Fagales)
Species Origin: Eastern North America
New Jersey Status: USDA Native
Habit: Medium-sized tree, 60 – 115’ high and 2-3’ wide, conical when young, becoming broadly spreading with age.
Habitat: Zone 3 – 9; grows in dry woods.
Trunk/Stem: Pale whitish gray shaggy, scaly, fissured with age.
Leaves: Deciduous, Simple, Alternate. Obovate in shape, 8” long x 4” wide; tapered at the base (notably, Q. robur also has a thinned base but the end is blunt, cordate), deeply cut into 2 – 4 lobes on each side but the invaginations are smooth. Leaf blade above (adaxial) pink-tinged and white-hairy becoming bright green and glabrous; below (abaxial) blade blue-green becoming glabrous. Leaves turning purple-red in autumn.
Flowers: Monoecious. Flowers without petals. Male flowers yellow green in drooping catkins; female flowers inconspicuous borne separately on the same plant in late spring. Flowers appear on old or new growth; staminate catkins pendent and clustered; its flowers comprise a 4 – 7 lobed calyx which encloses 6 stamens. The pistillate flowers are solitary or on few to many flowered spikes which form in the axial of new leaves. Individual flowers consist of a 6 lobed calyx surrounding 3-celled ovary; the whole is partly covered by the involucre.
Fruits and seeds: Acorn, 1” long, ¼ enclosed by rough textured, scaly cup. The acorns are born singly or in pairs on a short pedicel. Acorn ripen in one year. Trees can produce abundant crop of acorns in a good year which comes every 4-10 years.