The tree is a hybrid of Quercus robur f. fastigiata (upright English oak) and Quercus bicolor (swamp white oak).

[1] The hybrid is named for the American dendrologist George Ware, former Research Director at the Morton Arboretum in Illinois.

The mother tree of both cultivars is a Quercus robur f. fastigiata[2] (upright English oak, a narrow form) growing in Columbia, Missouri.

[2] 'Nadler' and 'Long' are highly resistant to powdery mildew,[2] which plagues the Q. robur parent.

This clone also exhibits heterosis (hybrid vigor).