Bur Oak

Quercus macrocarpa Michx.

         

        

       

All photographs are copyrighted and are the property of E. Brunner.

Family:  

Native or Introduced to Illinois: native 

Natural Habit in Illinois:  dry ridges to bottomland woods

Leaf:  The single leaves have five to nine rounded lobes, with a large end lobe. The leaves are divided in half near the center with a deep lobe almost to mid-vein.  They leaves are dark shiny green above, and light green to gray below.  The top portion of the leaf is more wavy than lobed.

Flower: Male and female flowers are inconspicuous and are borne in separate catkins (the tree is monoecious) on the current years branchlets. 

Fruit:  The acorn is large, almost round with a bur or moss-like, fringed cup covering half or more of the acorn.

Bark/Twig:  The thick, deeply furrowed bark breaks into distinct ridges.  On small branched and twigs it is brownish, roughened and corky.

Size/Form/Shape:  The Bur Oak is strong-branched, usually with a dense crown.

Other:  large shade tree for spacious areas; coarse interesting habit; adaptable to many soil conditions; prefers high pH; tolerates city conditions; slow growing

County Distribution Map for Illinois:  

Sources for the Sullivan Middle School Tree Identification Guide were obtained though the use of the following sites:

• Illinois Plant Information Network (ILPIN) @ http://www.fs.fed.us/ne/delaware/ilpin/ilpin.html#Background
• List of Woody Plants Native or Naturalized in Illinois @ http://www.inhs.uiuc.edu/~kenr/woody.html
• Tree Species @ http://ostermiller.org/tree/species.html
• Index to Eastern/Central Trees @ http://www.arborday.org/trees/ECtreelist.html
• ISU Forestry Extension Identification of Common Trees of Iowa @ http://www.extension.iastate.edu/Pages/tree/
• Key to Leaves of Virginia Trees @ http://www.fw.vt.edu/dendro/forsite/key/intro.htm
• List of Native Trees for Use Along Roadsides in Illinois @ http://www.inhs.uiuc.edu/~kenr/treetable.html
• The PLANTS Database @ http://plants.usda.gov/

The information below is from the National Arbor Day Foundation.  This information can be viewed in the original (source) form by visiting The National Arbor Day Foundation at http://www.arborday.org.

GROWING REQUIREMENTS/RATE
Sun Exposure:  This oak does well in ull sun.
Soil Type: The Bur Oak grows in acidic, alkaline, loamy, clay, sandy, wet, well-drained, wide range of soils; adapts well to urban setting and is drought tolerant.
Moisture:  Moderate moisture with some drought tolerance.
Growth Rate:  This tree grows at a slow growth rate.

Hardiness Zones: 3 - 8
This oak can be expected to grow in the zones shown in color in the arborday.org zone map.