Tuesday, September 12, 2017
The Bur Oak - Quercus marocarpa
The Bur Oak - Quercus marocarpa, is best identified by the combination of fiddle shaped leaves, winged twigs and large acorns with fringed cups. It is a deciduous tree that reaches heights of 80-160 feet tall on average. It grows in an upright, erect form with a single trunk and spreading crown. It is native to poorly drained woodlands, bottom lands, sandy plains, prairies, dry uplands and around clay or limestone between 0-1000 m. It can be found as far North as Manitoba, Ontario and New Brunswick on South through Tennessee, Oklahoma, Virginia and even portions of East/Central Texas and other portions of the Gulf Coast. The Bur Oak has the largest acorn of any Oak species North of Mexico and is also the most Northern ranging and cold tolerant of all Native American Oaks. It's range extends well into Canada but as the range continues North the size of the tree decreases, becomes shrubbier, less upright and the acorn size also decreases.
Image Citation:Jason Sharman, Vitalitree, Bugwood.org
The Bark is a dark gray in color, flattened with scaly ridges and deep vertical furrows. The leaves are alternate, simple, elliptic to obvate often fiddle shaped. The upper leaf surface is lustrous, dark green to greenish gray. The lower leaf surface is pale green with a thin covering of tiny branched hairs. The fruit is in the form of an ellipsoid acorn with a cup ranging from 1.5-5 cm deep that ancloses half of the light brown nut on a stout 6-20 mm long stalk.
Image Citation: Paul Wray, Iowa State University, Bugwood.org
The Bur Oak is similar to the White Oak and often confused to the untrained eye. It's recommended hardiness range is 3-8. Bur Oak is a shade tree, boasting a spreading canopy capable of blocking sunlight. It is often planted as a shade tree and prefers full sun (at least 6 hours direct sunlight per day). The acorns of the Bur Oak are the preferred food for wood ducks, wild turkeys, white-tailed deer, rabbits, mice, squirrels and other rodents.