ERICACEAE 725 



ovate-lanceolate, acute, pubescent or puberulous on the outer surface, persistent 

 under the fruit; corolla hypogynous, cylindrical to ovate-cylindrical, white, puberu- 

 lous, o-lobed, the lobes minute, ovate, acute, reflexed; stamens 10, included; fila- 

 ments subulate, broad, pilose, inserted on the very base of the corolla; anthers linear- 

 oblong, narrower than the filaments, the cells opening from the apex to the middle; 

 disk thin, obscurely 10-lobed; ovary broadly ovoid, pubescent, 5-celled; style colum- 

 nar, thick, exserted, crowned with a simple stigma; ovules attached to an axile 

 placenta rising from the base of the cell, ascending, amphitropous. Fruit a 5-celled 

 ovoid-pyramidal many-seeded capsule crowned with the remnants of the persistent 

 Style, 5-lobed, puberulous, loculicidally o-valved, the valves woody, separating from 

 the central persistent placentiferous axis, many-seeded. Seeds ascending, elongated; 

 seed-coat membranaceous, loose, reticulated, produced at the ends into long slender 

 points; embryo minute, axile in fleshy albumen, cylindrical; radicle terete, next the 

 hihim. 



The genus consists of a single species. 



The generic name is from 6vs and SfvSpav, in allusion to the acid foliage. 



1. Oxydendrum arboreum, DC. Sorrel-tree. Sour Wood. 



Leaves when they unfold bronze green, very lustrous and glabrous with the ex- 

 ception of a slight pubescence on the upper side of the midribs and a few scattered 

 hairs on the under side of the midribs and on the petioles, and at maturity o'-7' long, 

 l'-2' wide, turning bright scarlet in the autumn before falling; their petioles f 

 long. Flowers opening late in July or early in August, J' long, in panicles 7'-8' in 

 length. Fruit '-' long, hanging in drooping clusters sometimes a foot in length, 



ripening in September, the empty capsules often persistent on the branches until late 

 in the autumn; seeds about |' long, pale brown. 



A tree, occasionally 50-60 high, with a tall straight trunk 12'-20' in diameter, 

 slender spreading branches forming a narrow oblong round-topped head, and glabrous 

 branchlets yellow-green and marked by orange-colored lenticels when they first 

 appear, becoming in their first winter orange-colored to reddish brown. Winter-buds 

 about ^g' long, their inner scales at maturity 1' in length, ' wide, spatulate, acute at 

 the apex, and slightly puberulous on the inner surface and on the margins. Bark of 



