Celtis occidentalis, commonly known as the Common hackberry, is a medium-size deciduous tree native to North America. It is also known as the nettletree, 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 berries 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 forms a medium sized tree, thirty to fifty feet in height, with a slender trunk; but, it grow to over one hundred and thirty feet. 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 with less rainfall and poorer soils it normally averages about thirty feet in height, but at least one specimen was found at ninety five feet. The maximum age attained by hackberry is probably between 150 and 200 years.
The bark is light brown or silvery gray, broken on the surface into thick appressed scales and sometimes roughened with excrescenses; pattern is very distinctive. The branchlets are slender, light green at first, finally red brown, at length become dark brown tinged with red. The winter buds are axillary, ovate, acute, somewhat flattened, one-fourth of an inch long, light brown. Scales enlarge with the growing shoot, the innermost becoming stipules. No terminal bud is formed. The leaves are alternately arranged on stems, ovate to ovate-lanceolate, more or less falcate, two and a half to four inches (102 mm) long, one to two inches wide, very oblique at the base, serrate, except at the base which is mostly entire, acute. Three-nerved, midrib and primary veins prominent. They 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.
The flowers appear in May, soon after the leaves. Flowers born on slender drooping pedicels. The calyx is light yellow green, five-lobed, divided nearly to the base; lobes linear, acute, more or less cut at the apex, often tipped with hairs, imbricate in bud.
- Corolla: Wanting.
- Pistil: ovary superior, one-celled; style two-lobed; ovules solitary.
- Fruit: Fleshy drupe, oblong, one-half to three-fourths of an inch long, tipped with remnants of style, dark purple. Borne on a slender stem; ripens in September and October. Remains on branches during winter.