Identifying characteristics:
The hackberry is a moderately large tree, 50 to 70 feet tall, with a straight
trunk 1 to 2 feet in diameter. When young, the crown is weakly pyramidal,
becoming rounded, with ascending, spreading branches at maturity. The deciduous
leaves are simple, alternate, and
2 to 4 inches long. The veins form a network near the margin, with the three
principal veins meeting at a single point at the base, which is rounded
and uneven. The margins are coarsely toothed but entire near the base. Leaves
are thin, papery and rough above, and paler and hairy along the veins underneath.
The dull, light green leaves change to a light yellow or yellow-green in
the fall. The very small, greenish-yellow, apetalous flowers
appear solitary or in bunches of 2 or 3 in the axils of the emerging leaves
in spring. The fruit is a rounded,
tough-skinned, dark-purple drupe. A single, hard, brown seed is enclosed
by orange-colored flesh that tastes like a prune or a date. The leaf
scars are small, half-round, with 3 (sometimes 1) bundle scars. The
buds are 0.25 inches long, ovoid, pointed and closely appressed to
the twig. A terminal bud is absent. The 3 to 4 visible bud scales are light
brown and inconspicuously hairy. The grayish-brown bark
is rather thick, with distinctive, irregular, wart-like outgrowths or
ridges conspicuous even on young trees.
Similar species:
Ecology:
Distribution: Native to all of Iowa, this species is widely distributed
throughout the eastern US, and just into extreme southeast Canada.
Habitat: Although preferring moist, low-lying woods, this species also grows in dry, heavy soils or sandy, rocky soils, withstanding both alkaline and acid conditions. It is moderately fast-growing in good soils, hardy to zones 2 to 9 and can live up to 200 years. This species is resistant to Dutch elm disease and is often used as a replacement for the American elm tree (Ulmus americana). Although the hackberry suffers from no serious pest or diseases, insect-caused nipple galls on the leaf surface and clusters of upright branches forming witches' brooms, caused by insect mites and powdery mildew, often destroy the aesthetic appearance of the trees. The former can be controlled by spraying, and the latter-almost always associated with a tiny gall mite and powdery mildew fungus-can be removed by pruning. The hackberry lace bug, a sap feeder on the underside of the leaf surface, may cause bleaching of the leaves. In the fall, the adult insect sometimes bites humans, which may become a minor nuisance.
Uses:
Wood: The wood resembles that of elm, but has wider
sapwood and distinctive yellow streaks. The wood is ring-porous, coarse-textured
and hard. It is relatively weak, compared to oak and maple, and is thus
of limited importance. It is used for inexpensive furniture, millwork, sporting
goods, and veneer for plywood and containers.
Wildlife: Large fruit crops are regularly produced, making this a favorite food of robins, cardinals, flickers, cedar waxwings and other small birds, who help to distribute the seeds. Game birds like grouse, turkey and pheasant, as well as mammals like raccoons and squirrels feast on the fruit.
Horticulture: This is the largest landscape tree of the genus. Although it withstands drought, poorly-drained soils, and urban conditions, it is, however, not suitable as a street tree because it is susceptible to damage by wind and ice storms. This species is useful for conservation plantings in sites too wet for conifers. The vase-shaped or rounded crown casts good shade and the growth rate is moderately fast. The hackberry is suited for use as a shade tree in parks and large areas.
