Pignut Hickory Identification Guide
How to identify Pignut Hickory (Carya glabra) by its tight gray bark, 5-7 smooth leaflets, brown buds, and distinctive pear-shaped nuts.
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Key Identifying Features
Pignut Hickory (Carya glabra) is a common upland tree of dry eastern forests, growing 50-80 feet tall with a tall, straight trunk. Its name comes from the small, often bitter nuts once fed to pigs. Two combined features identify it: tight, gray bark with shallow, criss-crossing (diamond-patterned) ridges that does not peel in shaggy strips, and a distinctly pear- or pumpkin-shaped husk that splits only partway down.
- Tight gray bark with interlacing diamond ridges
- Compound leaves with 5 (sometimes 7) smooth leaflets
- Small pear-shaped husked nut, thin husk
Leaves & Stems
Leaves are pinnately compound, 8-12 inches long, usually with 5 leaflets (occasionally 7). The terminal three leaflets are notably larger than the lower pair. Leaflets are lance-shaped to oblong, finely toothed, and smooth and nearly hairless (the species name glabra means smooth/hairless), shiny dark green above and paler below. Fall color is golden yellow.
Twigs are slender, reddish-brown, and hairless. The terminal buds are brown, ovoid, and small to medium — not yellow (bitternut) and not large and fuzzy (mockernut). This bud size and smoothness help separate it from its relatives.
Flowers & Fruit
Greenish male catkins dangle in spring in branched clusters; female flowers are tiny spikes at twig tips. The fruit is a small, pear-shaped (obovoid) nut, often with a slight neck at the base where the husk narrows. The thin husk is smooth, splits only halfway or stays partly closed, and the nut shell is unwinged. Kernels are small and range from sweet to bitter depending on the tree.
How to Tell It Apart from Look-Alikes
- Bitternut hickory: yellow buds and 7-11 leaflets; pignut has brown buds and 5-7.
- Shagbark hickory: shaggy peeling bark and large buds; pignut bark is tight and ridged.
- Mockernut hickory: large fuzzy buds, densely hairy fragrant leaves, thick husk; pignut leaves are smooth and the husk is thin.
- Black walnut / butternut: chambered pith and far more leaflets; hickories have solid pith.
The combination of tight diamond-patterned bark, smooth 5-leaflet leaves, and a thin pear-shaped husk pins down pignut.
Where You'll Find It
Pignut Hickory thrives on dry ridges, upland slopes, and well-drained hillsides in oak-hickory forests across the eastern United States, from New England and southern Ontario south to Florida and west to the Mississippi Valley and eastern Texas. It is a classic component of dry upland hardwood stands and is more drought-tolerant than the bottomland hickories.
Quick ID Checklist
- Tight gray bark with shallow interlacing diamond ridges (not shaggy)
- 5-7 smooth, hairless leaflets per leaf
- Brown terminal buds (not yellow, not large/fuzzy)
- Pear-shaped, thin-husked nut splitting only partway
- Dry upland slopes and ridges in oak-hickory forest
Frequently asked questions
How do I distinguish pignut from shagbark hickory?
Bark is the quickest tell: shagbark peels in long, loose vertical strips, while pignut bark stays tight with shallow diamond-shaped ridges. Pignut also has fewer, smaller buds and a thinner husk.
Are pignut hickory nuts edible?
They are edible but usually small and bitter to slightly sweet depending on the individual tree, and the thin husk and hard shell make them low-value compared to shagbark nuts.
Why is it called pignut?
Early settlers turned hogs loose to forage on the fallen nuts, which were considered too bitter or small for people, hence pignut.
How many leaflets does pignut hickory have?
Typically 5, sometimes 7 — fewer than bitternut hickory, and the leaflets are smooth and hairless, matching the species name glabra.