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Editor's Picks

Karl Georg Theodor Kotschy was an Austrian botanist and...
Eike Jablonski | Jun 11, 2016
Quercus grisea - Greenlee County, AZ
This article is an account of the oak field trip organized...
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North American oaks have a northern temperate origin and...
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Plant Focus

Quercus acutissima subsp. kingii
Quercus acutissima Carruth. is a species whose natural distribution covers a vast territory in East and Southeast Asia, from central Nepal...

Hybrid Highlight: Quercus ×heterophylla F. Michx.

Quercus ×heterophylla in the Garden Kingdom of Dessau-Wörlitz, Germany. Photo: © Andreas Gomolka (click on image to enlarge)

Named in honor of one of America’s first botanists, John Bartram, Quercus ×heterophylla is known by many as Bartram’s oak. This interesting hybrid can be found in the US where the parent species of Q. rubra and Q. phellos overlap (essentially most of the midwestern to southeastern states) and in collections. This hybrid can also be found in Europe in arboreta and private collections. One of the largest European specimens stands in the Garden Kingdom of Dessau-Wörlitz, Germany. It measures over 15 ft in circumference and is 65 ft tall.  A noteworthy specimen in the US is located in Philadelphia, Pennsylvania and has nearly identical dimensions of the grand European tree (16 ft circumference,

Detail of leaves on the treee in Dessau-Wörlitz Photo: © Andreas Gomolka

 61 ft tall). This tree is believed to be a direct descendant of a Q. ×heterophylla grown by John Bartram on his property.

This is an attractive hybrid typically characterized by long, slender leaves with 6-8 shallow lobes. Acorns are typically small (3/8 to 1/2 inch diameter) with shallow, flattened cups. The acorns are usually light to medium brown with dark striations. Seedling trees will vary of course, some having larger leaves or lager acorns. This hybrid makes a pleasing street tree and there exists a great opportunity to make superior selections. 

A young Quercus ×heterophylla in central Missouri, USA Detail of leaves - Photos: © Ryan Russell