Black Locust
Family: Leguminosae or Fabaceae (View Members of Leguminosae)

Genus and species: Robinia pseudoacacia

Leaves: The leaves are pinnately compound and are 6-12" (15-30cm) long containing 7-19 leaflets, each 1-1.75" (2.5-4.5cm) long. (View Measured Leaf) The leaflets are paired, elliptical, and appear rounded at the edges. However, there is a small bristle tip at the end of each leaflet. The leaflets are not teethed and tend to droop slightly. They are more dull green on top than the Honeylocust, paler beneath and hairless. (View Leaves)

Bark: The bark is light gray in color and has deep, long ridges.(View Bark) The twigs are dark brown and have short, paired spines at the nodes.

Fruit: The fruit is a flat pod, about 2-4" (5-10cm) long. They are lighter brown, not as shiny and shorter than the pods of a Honeylocust. Each pod may contain about 3-14 dark brown, flattened seeds. Pods containing seeds are common among members of the Leguminosae family.(View Fruit)

Tree: The tree can grow to be 40-80' (12-24m) tall, usually has an irregularly shaped trunk and an open crown of branches, as pictured to the left.

Range and Habitat: These trees are commonly planted from Ontario, east to Massachusetts, but are commonly found naturally, south to Virginia, west to Oklahoma. They are usually found in sandy, moist, rocky soils, usually in open areas.

Black Locust Tree (Brandeis University, Waltham, MA, 9/30/02)
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