Quercus macrocarpa Michx.
Common Name: BUR OAK

Coefficient of Conservatism: 5
Coefficient of Wetness: 3
Wetness Index: FACU
Physiognomy: Nt Tree
Quercus macrocarpa acorns B. S. Walters acorns

Ranges from rich bottomlands and (especially northward) river banks or lake shores to dry sandy open upland forests or depressions in such forests. This was the characteristic scattered tree of savannas called “oak openings” in the early days of settlement in southern Michigan. Many fine large specimens of bur oak, some well over 200 years old, continue to grow as shade trees where they have escaped the ax, saw, and bulldozer, even in cities.

An occasional specimen of Q. bicolor may resemble this species, if the leaves are larger and more deeply lobed than usual, but the glabrous buds, long peduncles, and more whitened undersides of the leaves in Q. bicolor should distinguish it. The large “mossy cup” acorns of Q. macrocarpa are sessile or on peduncles at most about 1 cm long, but even in the absence of this distinctive fruit the species can usually be easily recognized by the large leaves, much more deeply lobed on the basal half than on the apical half.

Hybrids with Q. bicolor (Q. ×schuettei Trel.), appear to be more frequent in Michigan than those with Q. muehlenbergii (Q. ×deamii Trel.); an apparent hybrid with Q. prinoides, Q. ×beckyae Gaynor, has been found in Livingston Co.

Locations

Alpena County
Arenac County
Bay County
Benzie County
Berrien County
Branch County
Calhoun County
Cheboygan County
Chippewa County
    Including Drummond Island
Dickinson County
Eaton County
Emmet County
Genesee County
Gogebic County
Gratiot County
Hillsdale County
Huron County
Ingham County
Iosco County
Iron County
Isabella County
Jackson County
Kalamazoo County
Kent County
Lapeer County
Lenawee County
Luce County
Macomb County
Marquette County
Mecosta County
Menominee County
Missaukee County
Monroe County
Montcalm County
Muskegon County
Newaygo County
Oakland County
Ontonagon County
Osceola County
Oscoda County
Saginaw County
Schoolcraft County
Shiawassee County
St. Clair County
St. Joseph County
Tuscola County
Washtenaw County
Wayne County

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. October 25, 2014. http://michiganflora.net/species.aspx?id=1378.