Addisonia 37 



(Plate 139) 



OXYDENDRUM ARBOREUM 

 Sourwood 



Native oj the southeastern United States 



Family Ericackae Heath Family 



Andromeda arborea L. Sp. PI. 394. 1753. 

 Oxydendrum arhoreum DC. Prodr. 7: 601. 1839. 



A tree attaining a height of fifty to sixty feet. The thick reddish 

 grey bark is furrowed; the smooth young twigs are light green, 

 becoming orange-brown. The leaves, which turn scarlet in the 

 fall, are shining, and have stalks less than an inch long. The 

 blades are oblong to oval-lanceolate, up to six inches long, and 

 are smooth and bright green; they are rather long-pointed at the 

 apex, narrowed at the base, and have the margins sharply and 

 finely toothed. The white flowers, on short stalks, are nodding 

 and are arranged in one-sided racemes which are in panicles at the 

 ends of the branches; the persistent sepals are short; the ovoid- 

 cylindric corolla is about a half inch long and is five-toothed at 

 the apex. The stamens are ten, about as long as the corolla, with 

 the filaments wider than the anthers, which open by long slits. The 

 ovary is five-celled. The five-angled fruits, which are woody 

 and ovoid-pyramidal, are a sixth to a quarter of an inch long and 

 are on curved stalks; when mature they split into five valves. 



This tree grows wild from southern Pennsylvania and Maryland 

 to Florida, Tennessee, and lyouisiana. It is known locally as sour 

 gum, arrow-wood, titi, sorrel-tree, and lily-of- the- valley tree. It 

 occurs in woodlands on ridges rising above the banks of rivers, 

 preferring a well-drained gravelly soil. On the western slopes of 

 the Big Smoky mountains in Tennessee it is said to attain its 

 greatest size. The trunk is straight, rarely exceeding a foot in 

 diameter, the slender spreading branches forming a narrowly 

 oblong round-topped head. The leaves when they first unfold 

 are a shining bronzy green, later becoming bright green, and turn 

 to scarlet in the fall. It is hardy as far north as Massachusetts. 

 It flowers in the vicinity of New York late in July or early in August, 

 at a time when few trees or shrubs are in blossom, thus being of 

 decorative value not only on account of its attractive flowers, but 

 also on account of their timely appearance. It was cultivated in 

 England by Philip Miller as early as 1752. It has been in culti- 

 vation in the New York Botanical Garden since 1895; the specimen 



