Common Trees of the North Carolina Piedmont

Stephen M. Seiberling, Alan S. Weakley, and Peter S. White

Oxydendrum arboreum (L.) DC. Sourwood, sorrel-tree. Family Ericaceae. ITIS Taxonomic Serial Number 23690. USDA PLANTS Symbol OXAR. TROPICOS # 12300622.

Images • Branchlet with leaves. • Individual leaf. • Branchlet with buds. • Close-up of buds. • Branchlet with fruits. • Close-up of fruits. • Herbarium sheet 1. • Herbarium sheet 2. • Herbarium sheet 3.

Detailed Description:

Plant habit and life style. Plants Angiosperms, synoecious, (5–)15–20(–35) m tall.

Stems. Pith continuous. Young twigs (1-year-old or less) brown or green or olive-green or orange or red or reddish-brown or yellow-green, glabrous or glabrate, puberulent. Twigs (2–4 years old) glabrous. Leaf scars half-round or shield-shaped or triangular, bundle scars 1 per leaf scar, stipule scars absent. Bark of mature trunks checkered or furrowed or ridged.

Buds. Buds axillary, red or reddish-brown, 1–3.2 mm long, conic or globose, blunt or sharp, bud scales imbricate.

Leaves. Leaves deciduous, simple, petiolate, alternate, 8–20 cm long, 2–7.5 cm wide, elliptic or lanceolate or oblong, leaf margins entire or serrate or serrulate or ciliate, leaf apices acuminate, leaf bases cuneate or rounded. Leaf upper surface green, glabrous or glabrate. Leaf lower surface green, glabrous or glabrate or pubescent, puberulent or strigose. Leaf venation pinnate. Petioles 0.7–2.5 cm long, pubescent, puberulent. Stipules absent.

Flowers. Flowering May or June or July. Inflorescences axillary or terminal, panicles or racemes, flowers stalked. Flowers bisexual. Perianth. Calyx radially symmetric, synsepalous. Sepals 5 per flower, calyx tubes 1–1.5 mm long, spreading or ascending, deltoid or ovate, sepal apices acute, pubescent, puberulent, persistent. Corolla radially symmetric, urceolate, sympetalous. Petals 5 per flower, corolla tubes 5–9 mm long, spreading or ascending, cream or white, pubescent, caducous. Androecium. Stamens 10 per flower. Gynoecium. Ovaries superior, pistils 1 per flower. Gynoecium syncarpous, 5 carpels per flower, styles 1 per pistil, placentation axile.

Fruits. Fruits capsules, 0.5–1.3 cm long, gray, fruit maturation 1 years.

Habitat. Habitat bottomland forests or dry-mesic upland forests or mesic upland forests or mixed forest edges.

Special Diagnostic Characters. Leaves have a sour taste; clusters of empty capsules often persist on the trees into the winter; trunk often leans strongly.

Cite this publication as: ‘Stephen M. Seiberling, Alan S. Weakley, and Peter S. White (2005 onwards). Common Trees of the North Carolina Piedmont: Identification, Descriptions, Illustrations, and Glossary. Version: March 7, 2006. <>’.

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