Sourwood

Sourwood or Sorrel Tree (Oxydendrum arboreum) is the sole species in the genus Oxydendrum DC, in the family Ericaceae. It is native to eastern North America, from southern Pennsylvania south to northwest Florida and west to southern Illinois; it is most common in the lower chain of the Appalachian Mountains.

It is a small tree or large shrub, growing to 10-20 m tall with a trunk up to 50 cm diameter. The leaves are spirally arranged, deciduous, 8-20 cm long and 4-9 cm broad, with a finely serrated margin; they are dark green in summer but turn vivid red in fall. The flowers are white, bell-shaped, 6-9 mm long, produced on 15-25 cm long panicles. The fruit is a small woody capsule. The roots are shallow, and the tree grows best when there is little root competition; it also requires acidic soils for successful growth. The leaves can be chewed (but should not be swallowed) to help alleviate a dry feeling mouth. As the name of the tree implies, the effect is similar to chewing a sour piece of gum.

Description

 * Bark: Gray with a reddish tinge, deeply furrowed and scaly. Branchlets at first light yellow green, later reddish brown.
 * Wood: Reddish brown, sapwood paler; heavy, hard, close-grained, will take a high polish. Sp. gr., 0.7458, weight of cu. ft., 46.48.
 * Winter buds: Axillary, minute, dark red, partly immersed in the bark. Inner scales enlarge when spring growth begins.
 * Leaves: Alternate, four to seven inches long, one and a half to two and a half inches wide, oblong to ablanceolate, wedge-shaped at base, serrate, acute or acuminate. Feather-veined, midrib conspicuous.  They come out of the bud revolute, bronze green and shining, smooth, when full grown are dark green, shining above, pale and glaucous below.  In autumn they turn bright scarlet.  Petioles long and slender, stipules wanting.  Heavily laden with acid.
 * Flowers: June, July. Perfect, cream-white, borne in terminal panicles of secund racemes seven to eight inches long; rachis and short pedicels downy.
 * Calyx: Five-parted, persistent; lobes valvate in bud.
 * Corolla: Ovoid-cylindric, narrowed at the throat, cream-white, five-toothed.
 * Stamens: Ten, inserted on the corolla; filaments wider than the anthers; anthers two-celled; cells opening by long chinks.
 * Pistil: Ovary superior, ovoid, five-celled; style columnar; stigma simple; disk ten-toothed, ovules many.
 * Fruit: Capsule, downy, five-valved, five-angled, tipped by the persistent style, the pedicels curving.

Cultivation and uses
The Sourwood is perfectly hardy at the north and a worthy ornamental tree in lawns and parks. Its late bloom makes it desirable and its autumnal coloring is particularly beautiful and brilliant. The leaves are heavily charged with acid, and to some extent have the poise of those of the peach.

It is renowned for nectar, and for the honey which is produced from it. Juice from its blooms are used to make sourwood jelly. The shoots were used by the Cherokee and the Catawba to make arrowshafts.