The sourwood tree (Oxydendrum arboretum) grows from the southeastern part of Pennsylvania southward to northwestern sections of Florida and into Louisiana. The tree possesses features that make it stand out from other trees in the spring when its flowers bloom and in the fall when its leaves change color. The sourwood tree has great value as an ornamental species, with this member of the Heath family available in different cultivars.
The University of Connecticut Plant Database states that a sourwood tree growing in the wild has the potential to reach between 50 and 75 feet in height. The cultivars of this species are much smaller, with a 30-foot tree considered large. Sourwood leaves are between 3 and 8 inches in length and its delicate flowers are barely a quarter inch across.
The leaves of a sourwood tree will grow alternate on the twigs, with individual leaves developing at each separate node. The leaves are oblong but the ends taper into a slight point. The edges have very small serrations along them and the sourwood leaves are a shiny green color in the spring and summer months. Once fall comes though, these leaves turn into a wide array of brilliant colors, with scarlet, orange, yellow and purple leaves common. One aspect of the sourwood tree that endears it to landowners is the colorful leaves remain on the tree well into the fall.
Sourwood’s flowers give it the nickname of Lily-of-the Valley tree, as they closely resemble those from that ground cover plant. Sourwood flowers have a shape like a tiny bell and they will grow in drooping clusters as long as 10 inches at the end of the branches. The flowers are white and fragrant, attracting the attention of bees and other insects after blossoming in June and July.
Other features that help in identifying a sourwood tree include the fact that the leaves have a sour and slightly acidic taste to them. The bark of a sourwood is gray or red on the older specimens, possessing deepened furrows and ridges. The trunk of a sourwood tree, according to the Bernheim Arboretum and Research Forest website, typically has twists and turns in it as it grows in a crooked manner, often leaning to one side as well. The fruit the flowers produce is about one third of an inch in length and in clusters. It contains the seeds of the tree and often stays on the sourwood deep into the winter months before falling off.
A sourwood cultivar known as Mt. Charm has leaves that will change colors earlier than a sourwood growing in the wild, with the colors brighter than those of a normal sourwood. Chaemeleon, another sourwood hybrid, grows straighter than the wild sourwoods and its leaves can turn an assortment of bright colors during the autumn period. Albo marginatum is a sourwood cultivar with white margins around the leaves.