Common Trees of the North Carolina Piedmont

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

Quercus rubra L. Northern red oak, red oak. Synonyms Quercus borealis Michx. f., Quercus borealis var. maxima (Marsh.) Ashe, Quercus maxima (Marsh.) Ashe, Quercus rubra var. ambigua (A. Gray) Fern., Quercus rubra var. borealis (Michx. f.) Farw. Family Fagaceae. ITIS Taxonomic Serial Number 19408. USDA PLANTS Symbol QURU. TROPICOS # 13100118.

Images • Branchlet with leaves. • Individual leaf 1. • Individual leaf 2. • Individual leaf 3. • Individual leaf 4. • Branchlet with buds. • Close-up of buds. • Herbarium sheet 1. • Herbarium sheet 2. • Herbarium sheet 3.

Detailed Description:

Plant habit and life style. Plants Angiosperms, monoecious, (15–)20–35(–50) m tall.

Stems. Pith continuous. Young twigs (1-year-old or less) bronze or green or reddish-brown, 2–3.5(–4.5) mm wide, glabrous or glabrate or pubescent. Twigs (2–4 years old) glabrous. Leaf scars half-round, bundle scars numerous, stipule scars inconspicuous, stipule scars not circumferential. Bark of mature trunks checkered or furrowed or ridged.

Buds. Buds axillary or terminal, bud clusters at ends of twigs present, red or reddish-brown, 4–8 mm long, ellipsoid or ovoid or ovoid-ellipsoid, sharp, glabrous or glabrate or pubescent, bud scales imbricate.

Leaves. Leaves deciduous, simple, petiolate, alternate or spiral, 10–25 cm long, (5–)6–12(–15) cm wide, elliptic or oblong or obovate or ovate, leaf margins serrate, shallowly lobed or moderately lobed or deeply lobed, pinnately lobed, leaf lobes 7–11 per leaf, leaf apices acuminate or acute or apiculate, leaf bases cuneate or obtuse or rounded or truncate. Leaf upper surface green, glabrous or glabrate, tomentose. Leaf lower surface green or yellow-green, glabrous or glabrate or with tufts in vein axils, tomentose. Leaf venation pinnate. Petioles 2.5–5 cm long, glabrous. Stipules present, caducous, not circumferential.

Flowers. Flowering April or May. Inflorescences axillary, catkins or flowers solitary or spikes, flowers sessile. Flowers unisexual, epigynous. Perianth. Calyx radially symmetric, synsepalous. Sepals (2–)6(–8) per flower, ovate, sepal apices acute or rounded, caducous. Corolla absent. Androecium. Stamens (2–)6(–12) per flower, separate. Gynoecium. Ovaries inferior, pistils 1 per flower. Gynoecium syncarpous, 3 carpels per flower, styles 3 per pistil, placentation axile. Other floral features. Hypanthia present, involucres present.

Fruits. Fruits accessory fruits or acorns or nuts, 1.2–3 cm long, brown, fruit maturation 2 years.

Habitat. Habitat bottomland forests or mesic upland forests or mixed forest edges or suburban plantings.

Special Diagnostic Characters. Staminate flowers in pendent catkins, pistillate flowers solitary or in few- to many-flowered spikes; pistillate flowers enclosed by a scaly involucre which develops into the acorn cup.

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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