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Carya glabra — pignut hickory

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Facts

The undersides of the compound leaves of pignut hickory are mostly smooth (glabrous), only occasionally hairy -- hence its Latin name (glabra). This majestic tree can reach heights of 100 feet (30 meters) or more. The sturdy wood is highly shock-resistant and has been made into structures, such as skis and wagon axles, that have to withstand bumps and strains. Trees tend to fruit simultaneously in mast years, yielding high volumes of nuts. The nuts are rich in fats and proteins, and large quantities are consumed by bears and many other mammals.

Habitat

Forests, ridges or ledges, woodlands

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
Growth form
the plant is a tree
Leaf type
the leaf blade is compound (i.e., made up of two or more discrete leaflets
Leaves per node
there is one leaf per node along the stem
Leaf blade edges
the edge of the leaf blade has teeth
Leaf duration
the leaves drop off in winter (or they wither but persist on the plant)
armature on plant
the plant does not have spines, prickles, or thorns
Leaf blade length
200–600 mm
Leaf stalk
the leaves have leaf stalks
Fruit type (general)
  • the fruit is dry and splits open when ripe
  • the fruit is dry but does not split open when ripe
Bark texture
  • the bark of an adult plant is ridged or plated
  • the bark of an adult plant is thin and smooth
  • the bark of an adult plant peels off easily or hangs off
Twig winter color
  • brown
  • red
Bud scale number
there are three or more scales on the winter bud, and they overlap like shingles, with one edge covered and the other edge exposed
Show all characteristics

  • Buds or leaf scars

    Bud scale number
    there are three or more scales on the winter bud, and they overlap like shingles, with one edge covered and the other edge exposed
    Bud scar shape (Fraxinus)
    NA
    Collateral buds
    there are no collateral buds on the sides of the branches
    Leaf scar arrangement
    there is one leaf scar per node on the stem or twig
    Superposed buds
    there are no superposed buds on the branch
    Terminal bud
    the branch has a terminal bud on it
    Winter bud scale hairs
    • the winter bud scales are hairy
    • the winter bud scales have no hairs on them
    Winter bud scales
    the winter bud is perulate (partially or completely covered with one or more scales)
    Winter bud shape
    • the winter buds are globose (spherical, globe-shaped)
    • the winter buds are ovoid (egg-shaped)
    Winter bud stalks
    the winter buds have no stalks

  • Flowers

    Carpels fused
    the carpels are fused to one another
    Enlarged sterile flowers
    there are no enlarged sterile flowers on the plant
    Flower petal color
    NA
    Flower symmetry
    there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
    Hairs on ovary (Amelanchier)
    NA
    Hypanthium present
    the flower does not have a hypanthium
    Inflorescence position
    the inflorescences grow on the twigs
    Inflorescence type
    the inflorescence is an ament (catkin; slender, usually pendulous inflorescence with crowded unisexual flowers)
    Number of pistils
    1
    Ovary position
    the ovary is below the point of petal and/or sepal attachment
    Petal and sepal arrangement
    • the flower includes only one cycle of petals or sepals
    • the flower lacks sepals and petals
    Petal appearance
    NA
    Petal fusion
    NA
    Sepal appearance
    NA
    Sepal cilia (Ilex)
    NA
    Sepal tip glands
    NA
    Sepals fused only to sepals
    NA
    Stamen number
    • 4
    • 5
    • 6
    Stamen position relative to petals
    NA
    Stamens fused
    the stamens are not fused to one another

  • Fruits or seeds

    Berry color
    NA
    Fruit tissue origin
    there are no flower parts that form part of the fruit
    Fruit type (general)
    • the fruit is dry and splits open when ripe
    • the fruit is dry but does not split open when ripe
    Fruit type (specific)
    • the fruit is a drupe (fleshy, with a firm inner ovary wall that encloses a single seed)
    • the fruit is a nut (dry and indehiscent, with a hard wall, usually containing only one seed and usually subtended by an involucre)
    Nut with spines (Fagaceae)
    NA
    Wings on fruit
    there are no wings on the fruit

  • Glands or sap

    Sap color
    the sap is clear and watery
    Stalked glands on fruit (Rosa)
    NA

  • Growth form

    Growth form
    the plant is a tree

  • Leaves

    Hairs on underside of leaf blade
    • the underside of the leaf has hairs on it
    • the underside of the leaf has no hairs
    Hairs on upper side of leaf blade
    the upper side of the leaf is not hairy, or has very few hairs
    Leaf blade base shape
    • the base of the leaf blade is attenuate (tapering very gradually to a prolonged tip)
    • the base of the leaf blade is cuneate (wedge-shaped, tapers to the base with relatively straight, converging edges), or narrow
    Leaf blade base symmetry
    • the leaf blade base is asymmetrical
    • the leaf blade base is symmetrical
    Leaf blade bloom
    the underside of the leaf has no noticeable bloom
    Leaf blade edges
    the edge of the leaf blade has teeth
    Leaf blade edges (Acer)
    NA
    Leaf blade flatness
    the leaf is flat (planar) at the edges
    Leaf blade hairs
    at least some of the hairs on the leaf blade are branched
    Leaf blade length
    200–600 mm
    Leaf blade scales
    • there are no scales on the leaf blades
    • there are scales on the leaf blades
    Leaf blade shape
    • the leaf blade is elliptic (widest near the middle and tapering at both ends)
    • the leaf blade is oblanceolate (lance-shaped, but with the widest point above the middle of the leaf blade)
    • the leaf blade is oblong (rectangular but with rounded ends)
    • the leaf blade is obovate (egg-shaped, but with the widest point above the middle of the leaf blade)
    • the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
    Leaf blade texture
    • the leaf blade is coriaceous (has a firm, leathery texture)
    • the leaf blade is herbaceous (has a leafy texture)
    Leaf blade translucent dots
    there are no translucent dots on the leaf blade
    Leaf blade vein pattern
    the main veins of the leaf blade are pinnate (the secondary veins branch off at intervals from the main central vein) and non-arcuate (not arched towards the leaf tip)
    Leaf blade veins
    the leaf blade has one main vein running from the base toward the tip
    Leaf duration
    the leaves drop off in winter (or they wither but persist on the plant)
    Leaf form
    the plant is broad-leaved (with broadly flattened leaf blades)
    Leaf lobe tips (Quercus)
    NA
    Leaf midrib glands
    the midrib of the leaf blade lacks glands on the upper surface
    Leaf stalk
    the leaves have leaf stalks
    Leaf stalk attachment to leaf
    the petiole attaches at the basal margin of the leaf blade
    Leaf stalk nectaries
    there are no nectaries on the leaf stalk
    Leaf stalk shape
    the leaf stalk is not flattened
    Leaf teeth
    • the leaf blade margin has teeth, which themselves have smaller teeth on them
    • the leaf blade margin is serrulate (with forward-pointing) or denticulate (with outward-pointing) with tiny teeth
    Leaf teeth hairs (Carya)
    there are no tufts of hairs on the edges of the leaf blade
    Leaf type
    the leaf blade is compound (i.e., made up of two or more discrete leaflets
    Leaves per node
    there is one leaf per node along the stem
    Specific leaf type
    the leaf is compound, with a single terminal leaflet and more than two additional leaflets
    Stipules
    there are no stipules on the plant, or they fall off as the leaf expands

  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • forests
    • ridges or ledges
    • woodlands

  • Scent

    Plant odor
    • the plant does not have much of an odor, or it has an unpleasant or repellant odor
    • the plant has a pleasantly aromatic odor

  • Stem, shoot, branch

    Aerial roots
    the plant has no aerial roots
    Bark texture
    • the bark of an adult plant is ridged or plated
    • the bark of an adult plant is thin and smooth
    • the bark of an adult plant peels off easily or hangs off
    Branch brittleness (willows only)
    NA
    Branch cross-section
    the branch is circular in cross-section, or it has five or more sides, so that there are no sharp angles
    First-year cane (Rubus)
    NA
    Lenticels on twigs
    there are clearly lenticels on the twigs
    Pith type
    the pith inside the twig is solid, completely filled with spongy tissue
    Short shoots
    there are no peg- or knob-like shoots present
    Twig bloom
    there is no bloom on the twig
    Twig hairs
    the twigs have few or no hairs on them
    Twig papillae (Vaccinium species only)
    NA
    Twig scales
    there are scales on the twig surface
    Twig winter color
    • brown
    • red
    Wings on branch
    the branch does not have wings on it
    armature on plant
    the plant does not have spines, prickles, or thorns

Wetland status

Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)

In New England

Distribution

Connecticut
present
Maine
absent
Massachusetts
present
New Hampshire
present
Rhode Island
present
Vermont
present

Conservation status

Exact status definitions can vary from state to state. For details, please check with your state.

Massachusetts
widespread (S-rank: S5)
Vermont
rare (S-rank: S2)

From Flora Novae Angliae dichotomous key

2.  Carya glabra (P. Mill.) Sweet N

pignut hickory. Carya glabra (P. Mill.) Sweet var. hirsuta (Ashe) Ashe; C. glabra (P. Mill.) Sweet var. megacarpa (Sarg.) Sarg.; C. ovalis (Wangenh.) Sarg. var. hirsuta (Ashe) Sarg.; Hicoria 
glabra (P. Mill.) Britt.; H. glabra (P. Mill.) Britt. var. hirsuta Ashe • CT, MA, NH, RI, VT; reaching its northern limit in southern NH, but extending north along western VT into northern counties. Mainly dry-mesic, sometimes thin, soils of forests, woodlands, and ridges. This species 
is polymorphic in New England and consists of two intergrading morphologies. Plants with 
bark exfoliating in longitudinal plates, frequently red petioles, and drupes with exocarps promptly dehiscing to the base have been called Carya ovalis. Plants with close bark, frequently green petioles, and drupes with exocarps tardily splitting (or not splitting at all) represent C. glabra s.s. Though Manning (1950) maintained these two as separate species, 
he stated that trees with fruits intermediate between C. glabra and C. ovalis are almost 
as frequent as trees with characteristic fruits. Note that he also wrote these two species 
could only be separated by examination of mature fruits.

1×2. Carya cordiformis × Carya glabra → Carya ×‌demareei Palmer is a very rare hickory hybrid known from VT. It is identified by its smooth bark, leaves with mostly 7 leaflets, drupes with thin exocarp (2–3 mm thick) and exocarp sutures with very narrow wings, and terminal winter 
buds with weakly imbricate, yellow-brown to light red-brown scales.

Native to North America?

Yes

Sometimes confused with

Carya ovata:
leaves with mostly 5 leaflets, the margins of the leaflets with tufts of minute cilia borne along and just below the summit of the marginal teeth (vs. C. glabra, with leaves with mostly 5-9 leaflets, the margins of the leaflets without cilia or with few cilia not arranged in tufts).
Carya tomentosa:
branchlets stout, mostly 4-9 mm thick, and husk of fruit 4-13 mm thick (vs. C. glabra, with branchlets slender, mostly 2-4.1 mm thick, and husk 2-5 mm thick).

Synonyms

  • Carya glabra var. hirsuta (Ashe) Ashe
  • Carya glabra var. megacarpa (Sarg.) Sarg.
  • Carya ovalis (Wangenh.) Sarg. var. hirsuta (Ashe) Sarg.
  • Hicoria glabra (P. Mill.) Britt.
  • Hicoria glabra (P. Mill.) Britt. var. hirsuta Ashe

Family

Juglandaceae

Genus

Carya