Black Locust

Leguminosae

LIFE FORM: Tree

NATIVITY: Eastern North America

VEGETATIVE CHARACTERISTICS:

30 to 50 feet tall; leaves are alternate and pinnately compound with rounded leaflets; stems have sharp spines.

FLOWERS:

Pendulous clusters of showy, white flowers in late spring; fragrant.

FRUIT/DISPERSAL AGENTS:

Narrow, dry pods produced in fall; reproduces readily by root suckering.

ECOLOGICAL PREFERENCE:

Persists and spreads in dry soil through root suckering. Prefers minimally maintained public parks and open space; vacant lots and waste dumps; woodlands that develop on abandoned open space; unmowed highway banks and median strips with frequent salt applications; railroad tracks with ballast substrate.

ENVIRONMENTAL FUNCTION:

Bacterial root nodules fix atmospheric nitrogen, enriching poor soil; heat reduction in paved areas; salt tolerance along roadways; drought tolerance on compacted soils; air pollution tolerance; erosion control on slopes; soil building in degraded landscapes.

CULTURAL SIGNIFICANCE:

Widely planted since the 1700s as a source of rot-resistant wood for posts and poles, and has become natrualized throughout the world; planted as a street tree in New York City as early as 1751; Native Americans used the bark of the root to induce vomiting. Introduced as an ornamental species and for soil conservation purposes. Invasive species in minimally managed habitats.