Northern Hackberry

Celtis occidentalis

 This native New Jersey tree's small berries ripen in early September are eaten by birds as well as mammals. The tree also serves as a butterfly larval host. Its wood is not suitable as lumber.

The Northern Hackberry, also known as the common hackberry is a medium-sized tree, 30 to 50 ft in height,[3] with a slender trunk. In the best conditions in the southern Mississippi Valley area, it can grow to 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 maximum age attained by hackberry is probably between 150 and 200 years in ideal conditions.[1]

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.[2] The remarkable bark pattern is even more pronounced in younger trees, with the irregularly spaced ridges 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,12 2 - 43⁄4 in long by 11⁄4 – 31⁄2 in,[3] 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.[2]

The flowers are greenish and appear in May, soon after the leaves. They are polygamo-monoecious, meaning that there are three kinds: staminate (male), pistillate (female), perfect (both female and male). They are born on slender drooping pedicels.[2]

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. There is no corolla.[2]

 There are five stamens, which are hypogynous; the filaments are white, smooth, slightly flattened and gradually narrowed from base to apex; in the bud incurved, bringing the anthers face to face, as flower opens they abruptly straighten; anthers extrorse, oblong, two-celled; cells opening longitudinally.[2]

 The pistil has a two-lobed style and one-celled superior ovary containing solitary ovules.

 The fruit is a fleshy, oblong drupe, 1⁄4 to 3⁄8 in (0.64 to 0.95 cm) long, tipped with the remnants of style, dark purple when ripe. It is borne on a slender stem and ripens in September and October. It remains on the branches during winter. The endocarp contains significant amounts of biogenic carbonate that is nearly pure aragonite.[4]

 The common hackberry is native to North America from southern Ontario and Quebec, through parts of New England, south to North Carolina-(Appalachia), west to northern Oklahoma, and north to South Dakota. Hackberry's range overlaps with the sugarberry (Celtis laevigata), making it difficult to establish the exact range of either species in the South. Although there is little actual overlap, in the western part of its range the common hackberry is sometimes confused with the smaller netleaf hackberry (Celtis reticulata), which has a similar bark. Hackberry grows in many different habitats, although it prefers bottomlands and soils high in limestone. Its shade tolerance is greatly dependent on conditions. In favorable conditions its seedlings will persist under a closed canopy, but in less favorable conditions it can be considered shade intolerant.

[1]  Krajicek, John E.; Williams, Robert D. (1990). "Celtis occidentalis". In Burns, Russell M.; Honkala, Barbara H. (eds.). Hardwoods. Silvics of North America. Washington, D.C.: United States Forest Service (USFS), United States Department of Agriculture (USDA). Vol. 2 – via Southern Research Station.

[2] Keeler, Harriet L. (1900). Our Native Trees and How to Identify Them. New York: Charles Scribner's Sons. pp. 249–252.

[3] Sherman-Broyles, Susan L.; Barker, William T.; Schulz, Leila M. (1997). "Celtis occidentalis". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 3. New York and Oxford – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.

[4] Wang, Jang; Jahren, A. Hope; Amundsen, Ronald (1996). "Potential For [Carbon 14] Dating Of Biogenic Carbon In Hackberry (Celtis) Endocarps". Quaternary Research. 47: 337–343. doi:10.1006/qres.1997.1894. S2CID 49232599