74 Oxydendrum arboreumCommon Names: sourwood, sorrel tree, lily-of-the-valley tree Family: Ericaceae (heath Family)
The sourwood is a deciduous, medium tall tree that grows to heights of 30-60 ft (9-18.3 m). The tree has a slender pyramid form often with a curved or leaning trunk. The bark is rusty-brown and smooth when young later becoming rough and furrowed. Sourwood has simple oblong leaves, up to 10 in (25 cm) long that are rich green and glossy on top. The attractive leaves are held alternately on the stems and, like the sap, have an acid taste. Sourwood is brilliant in fall when the leaves turn red and scarlet and sometimes almost purple. In spring and early summer white blossoms are borne on long drooping stalks called racemes that are 8-10 in (20-25 cm) in length. The small white flowers are about 1/3 in (0.8 cm) long and shaped like urns held upside down along the length of the raceme. The blossoms are fragrant and resemble those of its cousin the blueberry, another member of the Ericaceae (heath family). At the tip of each branch several racemes are held in groups called panicles that droop toward the ground and impart a graceful aspect to this fine little tree. Due to the similarity of the flowers and its fragrance, this tree is also commonly called the lily-of-the-valley tree.
Sourwood, Oxydendron arboreum, is a native of the southeastern United States where it occurs in rich, mixed hardwood and softwood forests throughout most of the region.
CultureLight: Sun to partial shade. Best in light shade. Moisture: Moist but well drained. Water during droughts. Hardiness: USDA Zones 5 - 9. Propagation: Seeds are sown in autumn. Root semiripe cuttings in summer, treat with rooting hormone powder for best results.
The sourwood is sometimes used as an ornamental background tree for its fall color. The tree is also spectacular in late spring when in bloom. It holds it's fragrant white flowers against lustrous foliage for almost a whole month and creates quite a show as a specimen tree on an expanse of lawn. Sourwood is difficult to transplant successfully so it is best to obtain small plants in containers.
The graceful curvature, drooping white blossoms, and predictable red fall foliage make the sourwood a good choice for woodland and naturalistic landscapes. When in bloom the honeybee will seek out the trees' abundant white flowers that it uses to create a delicious treat. Sourwood honey is offered for sale in some areas of its native range.
Sourwood is the only species in the genus Oxydendron. That is a shame because Oxydendron is a cool name. Oxy- is Greek for "acid" or "sharp". Dendron is from the Greek for "tree" so this is a very descriptive name that references the plant's acidic (sour to the taste) foliage. Likewise the word "oxygen" is made up of oxy (acid) and geinomai which is also Greek and means "to bring forth". To early chemists oxygen was the substance that, when reacted with nitrogen, sulfur and other compounds brought forth nitric acid, sulfuric acid and which have nothing to do with sourwood trees!
Jack Scheper 04/27/97; updated 10/19/00, 06/26/03, 10/3/03, 4/19/04