Common Trees of the North Carolina Piedmont

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

Carya alba (L.) Nutt. ex Ell. Mockernut hickory, white hickory, white-heart hickory. Synonyms Carya tomentosa (Lam. ex. Poir.) Nutt., Hicoria alba (L.) Britt. Family Juglandaceae. ITIS Taxonomic Serial Number 501306. USDA PLANTS Symbol CAAL27.

Images • Individual leaf. • Branchlet with buds. • Close-up of buds. • Close-up of leaf scar 1. • Close-up of leaf scar 2. • Herbarium sheet 1. • Herbarium sheet 2. • Herbarium sheet 3. • Herbarium sheet 4. • Herbarium sheet 5.

Brief Description: A medium to large-sized, deciduous tree, typically ranging from 20–35 m (65–115 ft.) tall when fully grown. Buds are relatively large (8–20 mm long), and grayish to reddish brown, (tan, after the outer scales fall), with imbricate bud scales. Twigs are relatively stout. Bark of mature trunks is gray, with furrows and ridges, but not shaggy. Leaves are alternate, large (usually 20–50 cm long), and pinnately compound, with 7–9 (occasionally 5) leaflets. Leaflets are obovate or oblancoleate to oval or ovate in shape, with coarsely to finely serrate margins, and are densely hairy on the lower surface. Leaves produce a pungent odor when bruised or crushed. Petiole and rachis are persistently 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 large (3–8 cm long) nuts enclosed in a thick (4–10 mm) husk that typically splits into four sections. Mockernut hickory is one of the most common trees in the North Carolina Piedmont.

Detailed Description:

Plant habit and life style. Plants Angiosperms, monoecious, (10–)20–35(–45) m tall.

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

Buds. Buds axillary or terminal, gray or reddish-brown or silver or tan, 8–20 mm long, ellipsoid or globose or ovoid or ovoid-ellipsoid, blunt or sharp, pubescent, pilose or tomentose, bud scales imbricate.

Leaves. Leaves deciduous, compound, once pinnately compound, petiolate, alternate, (14–)20–50 cm long. Leaf upper surface green or yellow-green, glabrous or glabrate or pubescent, puberulent. Leaf lower surface brown or green or orange or yellow-green, pubescent, hirsute or stipitate glandular or tomentose. Leaflets petiolulate or nearly sessile or sessile, (5–)7–9 per leaf, 4–22 cm long, 2–12.5 cm wide, lanceolate or oblanceloate or obovate or oval or ovate, leaflet margins serrate or serrulate, leaflet apices acuminate or acute, leaflet bases attenuate or cuneate or oblique or rounded, leaflet venation pinnate, terminal leaflet present (odd-pinnate). Petioles 3–12 cm long, pubescent, hirsute, scaly. Rachises pubescent, hirsute, scaly. Stipules absent.

Flowers. Flowering March or April or May. Inflorescences axillary or terminal, catkins or spikes, flowers sessile. Flowers unisexual or pistillate or staminate, epigynous. Perianth. Calyx radially symmetric, synsepalous. Sepals 2–4 per flower, green or yellow-green, persistent. Corolla absent. Androecium. Stamens (3–)4–10(–15) 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, 3–8 cm long, brown or reddish-brown, fruit maturation 1 years.

Habitat. Habitat bottomland forests or disturbed and weedy areas or dry-mesic upland forests or mesic upland forests or mixed forest edges or suburban plantings.

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; lower leaf surfaces, petioles and rachises persistently hairy; twigs relatively stout.

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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