Leaves are opposite, entire, or shallowly lobed. Leaves may be somewhat toothed on young plants. Lavender flowers open in terminal panicles. The fruit is a two-valved capsule with numerous winged seeds.
Leaves are usually entire but are sometimes three-lobed on vigorous plants.
Pith is chambered or sometimes hollow. Flowers are large, violet, and slightly fragrant. May or June flowers are followed by fruit in September to November. This tree has escaped cultivation in few local areas of southern Ohio. In the Smokey Mountain National Park this tree has destroyed native vegetation on rocky sites such as cliff faces and is viewed as a serious weed.