Sourwood (Oxydendrum arboreum) is another name for the sorrel tree, the only species within the genus Oxydendrum, and belongs to the azalea family. It is a slow-growing deciduous tree that can be found across Southeastern United States.

Leaves

Leaves of the sourwood are oblong and can grow four to seven inches long (up to 10 inches) and 1.5 to 2.5 inches across. Leaves form alternately (growing on both sides of the stem, each leaf being placed a little further along than the other). The sourwood tree leaves are green and glossy on top. In the fall the leaves turn red to almost purple.

Bark and Roots

The bark of the sourwood is gray with highlights of red, and is smooth when young but becomes furrowed and roughens as it ages. The roots of the sourwood are shallow and fine in shape (as is common with members of the azalea family), as well as sensitive to under- and over-watering.

Flowers and Fruit

Sourwood flowers are cream colored, shaped like urns and grow off of curving pannicles (stem extensions for flowers) seven to eight inches long. They bloom in June and July. Sourwood fruit comes in the form of brown capsules 0.25 to 0.50 inches in diameter that ripen in September and October. The trees release fruit through the winter.

Height and Shape

Sourwood trees grow from 30 to 60 feet tall (often with a curved trunk), but can reach around 70 feet. Their crowns have a narrow pyramid shape and a rounded top.

Habitat

Sourwood requires partial shade, low watering and well-drained, gritty-textured acidic soil. It doesn't do well in urban environments due to habitat sensitivities such as soil compaction, root pollution and having its roots disturbed

Function

The sourwood is planted as an ornamental. It can be used for its wood, which takes a high polish, but it is not considered valuable.

Source:

Floridata.com: Oxydendrum Arboreum

Northeastern Area State & Private Forestry: Sourwood

More Information:

Native Plant Database: Oxydendrum Arboreum (L.) DC.

Our Native Trees and How to Identify Them; Harriet L. Keeler; 1900

Oxydendrum Arboreum; Edward F. Gilman and Dennis G. Watson