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Editor's Picks

Group photo at Harvard Herbarium
The Harvard University Herbaria hosted a novel Oak Taxonomy...
Jeannine Cavender-Bares | Apr 21, 2026
Morgan and friends in Argentina
Visits to three collections of Quercus in Buenos Aires...
Morgan Santini | Apr 05, 2026
Michel Duhart and Paco Garin at Jardín Botánico Wilson, Costa Rica
On April 1st, the very day he turned 103, a great friend...
Francisco Garin Garcia | Apr 05, 2026

Plant Focus

Quercus orocantabrica
Roderick Cameron and Carlos Vila-Viçosa give an account of this intriguing species from northwestern Iberia with a complex taxonomic and...

Hybrid Highlight: Quercus ×heterophylla F. Michx.

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

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Quercus ×heterophylla in the Garden Kingdom of Dessau-Wörlitz, Germany © Andreas Gomolka
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Detail of the leaves on the tree in Dessau-Wörlitz  © Andreas Gomolka

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. 

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