Pignut Hickory

Family: 
Juglandaceae (walnuts)
Description: 

A medium-sized tree with a rather narrow crown, 2-4 times longer than broad.

Leaves alternate, feather-compound, 8-12 inches long, with 5 (rarely 7) leaflets. Leaflets lance-shaped, narrow at base or near middle; margin toothed; tip tapered to a point. Upper surface yellow-green, smooth; under surface paler and smooth or hairy along veins. Bright yellow in fall.

Bark gray, thin, tight, rough from numerous shallow, criss-crossing cracks forming close, flattened scales.

Twigs rather slender, reddish-brown, smooth; pores pale.

Flowers April-May, male and female flowers separate on same tree; male catkins 3-branched, yellowish-green; female flowers few.

Fruits September-October, variable, usually pear- or egg-shaped, often with a necklike base; about 1¼ inches long; husk dark brown, thin, splitting late along 2-4 lines or not at all. Nut pear-shaped with a short beak.

Size: 
Height: to 80 feet.
Habitat and conservation: 
Dry upland woods, usually in acid souls derived from chert, sandstone or igneous rock, especially in the Ozarks; also in sandy or gravelly soils of dry upland wooded ridges in southeastern Missouri’s Crowley Ridge. A slow to moderately fast-growing tree, depending on soils. Trees are usually 25-30 years old before they begin producing nuts; it takes twice that time to begin full production.
Distribution in Missouri: 
Mostly in the eastern Ozarks but can be found scattered throughout southern Missouri and in a few counties just north of the Missouri River.
Human connections: 
The tough, rugged wood has been used for fuel and for tools that must withstand violent blows and friction, such as axe handles and wagon wheel hubs. Settlers used the bitter nuts to feed pigs (hence the name) and made brooms from the shredded wood.
Ecosystem connections: 
Squirrels, mice, deer and more eat the nuts. Squirrels also eat the buds. Like other hickories, the leaves are eaten by caterpillars of several large, showy moths, including the luna moth, several underwings and the giant regal moth.