Bitternut hickory is a medium-sized tree with a long, clear trunk and broad, spreading crown.
Leaves are alternate, pinnately compound, 6–12 inches long, with 7–9 elliptical, toothed leaflets. Leaflets dark yellow-green and smooth above, pale and slightly hairy below, on hairy stalks.
Bark is smooth and light gray when young, shallowly grooved with thin, flat, interconnecting ridges with age, not becoming scaly or shaggy.
Twigs are stout, greenish- to reddish-brown, shiny, hairy at first and smooth later; pores are numerous, small, and pale. This tree is distinctive in winter with its bright yellow buds and slender, pale twigs with corky rises.
Flowers April–May. Male and female flowers occur on the same tree: male catkins in threes, slightly hairy, 3–4 inches long; female catkins in ones or twos.
Fruits September–October, solitary or paired nuts, nearly globe-shaped, covered by a thin yellow-green husk with yellow scales, partly winged along the lines where it splits. Nut tip is sharp. Kernel is bitter.
Height: to 80 feet.
Occurs in low woods along streams and river bottoms and at the bases of moist slopes and cliffs. Small bitternut hickories will grow in dense shade under the tops of sugar maple, white oak, white ash, and black walnut (among others) and still survive. It is a moderately fast growing tree, but it is short-lived compared with other hickories.
Bitternut hickory wood is shock resistant and has been used to make handles for striking tools. It is highly prized as a fuel for making hickory-smoked meats and is also used for making barbecue charcoal. It also makes an excellent fuelwood for cook stoves, furnaces, or fireplaces.
Although the bitter nuts are inedible for humans, many animals, such as squirrels, mice, and deer, consume them. Squirrels also nibble on the buds. Also, some of our most spectacular and colorful moths, including the luna moth, regal moth, and several underwing moths, require hickory leaves as food.
There are no sharp dividing lines between trees, shrubs, and woody vines, or even between woody and nonwoody plants. “Wood” is a type of tissue made of cellulose and lignin that many plants develop as they mature — whether they are “woody” or not. Trees are woody plants over 13 feet tall with a single trunk. Shrubs are less than 13 feet tall, with multiple stems. Vines require support or else sprawl over the ground.