Black hickory is a small to medium tree with short, crooked branches and a narrow crown.
Leaves are alternate, feather-compound, 8–12 inches long. Leaflets usually 7, lance- to pear-shaped, 4–6 inches long, toothed; lower surface yellow-green with rusty hairs; leaf stalks with rusty hairs and tiny scales.
Bark is dark gray to black, tight, not scaly, with irregular blocky ridges and deep furrows.
Twigs are slender, often crooked, tapering abruptly to the terminal bud. Young twigs and terminal buds have fuzzy, rusty scales with tiny yellow dots.
Flowers April–May. Male and female flowers separate on the same tree. Male catkins in threes, 2–3 inches long; female flowers 1–2 with reddish hairs.
Fruits September–October, single or in small clusters. Nuts globe- or pear-shaped, 1¼–2 inches long, rather flattened; husk thin, brown, covered with yellow scales; kernel small, round, sweet, edible.
Similar species: Distinguished from pignut hickory by 7 (not 5) leaflets, tapering twigs, and the yellow bud dots.