Celtis occidentalis, commonly known as the common hackberry, is a large deciduous tree native to North America. It is also known as the nettletree, sugarberry, beaverwood, northern hackberry, and American hackberry. It is a moderately long-lived hardwood with a light-colored wood, yellowish gray to light brown with yellow streaks.
The common hackberry is easily distinguished from elms and some other hackberries by its cork-like bark with wart-like protuberances. The leaves are distinctly asymmetrical and coarse-textured. It produces small fruits that turn orange-red to dark purple in the autumn, often staying on the trees for several months. The common hackberry is easily confused with the sugarberry (Celtis laevigata) and is most easily distinguished by range and habitat. The common hackberry also has wider leaves that are coarser above than the sugarberry.
The common hackberry is a medium-sized tree, 9 to 15 metres (30 to 50 ft) in height, with a slender trunk. In the best conditions in the southern Mississippi Valley area, it can grow to 40 metres (130 ft). It has a handsome round-topped head and pendulous branches. It prefers rich moist soil, but will grow on gravelly or rocky hillsides. The roots are fibrous and it grows rapidly. In the western part of its range, trees may still grow up to 29 m (95 ft). The maximum age attained by hackberry is probably between 150 and 200 years in ideal conditions.
The bark is light brown or silvery gray, broken on the surface into thick appressed scales and sometimes roughened with excrescences; the pattern is very distinctive. The remarkable bark pattern is even more pronounced in younger trees, with the irregularly-spaced ridges resembling long geologic palisades of sedimentary [layered] rock formations when viewed edge-wise [cross-section]. Coins as large as USA quarters can easily be laid flat against the valleys, which may be as deep as an adult human finger.
The branchlets are slender, and their color transitions from light green to red brown and finally to dark red-brown. The winter buds are axillary, ovate, acute, somewhat flattened, one-fourth of an inch long, light brown. The bud scales enlarge with the growing shoot, and the innermost become stipules. No terminal bud is formed.
The leaves are alternately arranged on the branchlets, ovate to ovate-lanceolate, often slightly falcate, 5–12 cm (2–4 3⁄4 in) long by 3–9 cm (1 1⁄4–3 1⁄2 in), very oblique at the base, with a pointed tip. The margin is serrate (toothed), except at the base which is mostly entire (smooth). The leaf has three nerves, the midrib and primary veins prominent. The leaves come out of the bud conduplicate with slightly involute margins, pale yellow green, downy; when full grown are thin, bright green, rough above, paler green beneath. In autumn they turn to a light yellow. Petioles slender, slightly grooved, hairy. Stipules varying in form, caducous.