Common Trees of the North Carolina Piedmont

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

Carya glabra (P. Mill.) Sweet Pignut hickory, hairy pignut hickory, sweet pignut. Synonyms Carya glabra var. hirsuta (Ashe) Ashe, Carya glabra var. megacarpa (Sarg.) Sarg., Hicoria glabra (P. Mill.) Britt., Hicoria microcarpa (Nutt.) Britt. Family Juglandaceae. ITIS Taxonomic Serial Number 19231. USDA PLANTS Symbol CAGL8. TROPICOS # 16700022.

Images • Individual leaf 1. • Individual leaf 2. • Branchlet with buds. • Close-up of buds. • Close-up of leaf scar. • 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 15–30 m (50–100 ft.) tall when fully grown. Buds are relatively large (3–15 mm long), and reddish brown to tan, with imbricate bud scales. Twigs are relatively slender. Bark of mature trunks is gray, with furrows and ridges, sometimes with small exfoliating scales, but not shaggy. Leaves are alternate, large (15–60 cm long), and pinnately compound, with 5–7 (occasionally 3 or 9) leaflets. Leaflets are oblancoleate to obovate or lanceolate to oval in shape, with coarsely to finely serrate margins. The lower surface of leaflets with no hairs to densely hairy. Leaves produce a pungent odor when bruised or crushed. Petioles lack hairs at the base, but become hairy closer to the rachis, which also lacks hairs or is finely hairy. Separate male and female inflorescences occur on the same tree, the male flowers in drooping catkins, the female flowers in short, terminal clusters. Fruits are typically medium to large sized (2.5–5 cm long), often pear-shaped nuts, enclosed in a moderately thick (2–5 mm) husk that often splits into four sections, although sometimes not splitting at all, or only along one or two sutures.

Detailed Description:

Plant habit and life style. Plants Angiosperms, monoecious, (5–)15–30(–45) m tall.

Stems. Pith continuous. Young twigs (1-year-old or less) gray or reddish-brown, glabrous. Twigs (2–4 years old) glabrous. Leaf scars heart-shaped or oval or three-lobed, bundle scars numerous, stipule scars absent. Bark of mature trunks exfoliating or flaky or furrowed or ridged.

Buds. Buds axillary or superposed or terminal, brown or reddish-brown or tan, 3–15 mm long, ovoid, sharp, glabrous or pubescent, hirsute, bud scales imbricate.

Leaves. Leaves deciduous, compound, once pinnately compound, petiolate, alternate, 15–60 cm long. Leaf upper surface green or yellow-green, glabrous or glabrate. Leaf lower surface green, glabrous or glabrate or pubescent or with tufts in vein axils. Leaflets petiolulate or nearly sessile or sessile, (3–)5–7(–9) per leaf, 3–22.5 cm long, 1.8–13 cm wide, lanceolate or oblanceloate or obovate or oval or ovate, leaflet margins serrate or serrulate, leaflet apices acuminate or acute, leaflet bases cuneate or oblique or rounded, leaflet venation pinnate, terminal leaflet present (odd-pinnate). Petioles 3–14 cm long, glabrous or pubescent. Rachises glabrous or pubescent, puberulent. Stipules absent.

Flowers. Flowering April or May. Inflorescences axillary or terminal, catkins or fascicles 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(–6) 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, (1.5–)2.5–5 cm long, brown or reddish-brown or tan, 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 when mature, revealing the nut (sometimes not splitting, or splitting only along one or two sutures); 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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