Common Trees of the North Carolina Piedmont

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

Carya cordiformis (Wangenh.) K. Koch Bitternut hickory, pignut. Synonyms Hicoria cordiformis (Wangenh.) Britt. Family Juglandaceae. ITIS Taxonomic Serial Number 19227. USDA PLANTS Symbol CACO15. TROPICOS # 16700018.

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

Brief Description: A medium to large-sized, deciduous tree, typically ranging from 15–35 m (50–115 ft.) tall when fully grown. Terminal buds are relatively large (10–19 mm long), and sulfur yellow to tan, with valvate bud scales. Twigs are relatively slender. Bark of mature trunks is gray or brownish, initially with a smooth texture, becoming furrowed and ridged with age, sometimes with small exfoliating scales, but not shaggy. Leaves are alternate, moderately large (15–40 cm long), and pinnately compound, with 7–9 (occasionally 5, 11, or 13) leaflets. Leaflets are ovate to lanceolate or obovate to oblancoleate in shape, sometimes falcate, with coarsely to finely serrate margins. The lower leaf surface bears hairs along the larger veins, the remaining portions with few to many hairs. Leaves produce a pungent odor when bruised or crushed. Petioles lack hairs at the base, but become hairy closer to the rachis, which is also hairy. Separate male and female inflorescences occur on the same tree, the male flowers in drooping catkins, the female flowers in short, terminal spikes. Fruits are relatively small (2–3.6 cm long) nuts enclosed in a thin (2–3 mm) husk. The husk is 4-winged above the middle, has a short point at the end, and typically splits into four sections about half it’s length.

Detailed Description:

Plant habit and life style. Plants Angiosperms, monoecious, (10–)15–35(–50) m tall.

Stems. Pith continuous. Young twigs (1-year-old or less) brown or green or reddish-brown or tan, glabrous or glabrate. Twigs (2–4 years old) glabrous, scaly or without special surface features. Leaf scars heart-shaped or three-lobed, bundle scars numerous, stipule scars absent. Bark of mature trunks exfoliating or flaky or furrowed or plated or ridged or smooth.

Buds. Buds axillary or superposed or terminal, orange or tan or yellow, 3–19 mm long, ovoid, blunt or sharp, glabrous or glabrate or pubescent, pilose, bud scales valvate.

Leaves. Leaves deciduous, compound, once pinnately compound, petiolate, alternate, 15–40 cm long. Leaf upper surface green or yellow-green, glabrous or glabrate or pubescent, villous. Leaf lower surface green, glabrate or pubescent or with tufts in vein axils, villous. Leaflets petiolulate or nearly sessile or sessile, (5–)7–9(–13) per leaf, 2.5–20 cm long, 1–8.5 cm wide, falcate or lanceolate or oblanceloate or obovate or ovate, leaflet margins serrate or serrulate, leaflet apices acuminate, leaflet bases attenuate or cuneate or oblique or rounded, leaflet venation pinnate, terminal leaflet present (odd-pinnate). Petioles 3–7 cm long, glabrous or glabrate or pubescent, hirsute. Rachises pubescent. Stipules absent.

Flowers. Flowering April. Inflorescences axillary or terminal, catkins or flowers solitary or spikes, flowers sessile. Flowers unisexual or pistillate or staminate, epigynous. Perianth. Calyx radially symmetric, synsepalous. Sepals 2–4 per flower, persistent. Corolla absent. Androecium. Stamens 4 per flower, separate. Gynoecium. Ovaries inferior, pistils 1 per flower. Gynoecium syncarpous, 2 carpels per flower, placentation apical or basal. Other floral features. Hypanthia present.

Fruits. Fruits nuts, 2–3.6 cm long, brown, fruit maturation 1 years.

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

Special Diagnostic Characters. Leaves release a pungent odor when bruised or crushed; fruits with a husk that splits into 4 sections (partially or to the base) when mature, revealing the nut; twigs relatively slender.

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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