Locust, Black

Here we have the Black Locust, or Robinia pseudoacacia, now widespread in the Midwest but originally native to the eastern United States. This medium-sized tree typically reaches heights of less than 80 feet and rarely reaches more than 100 years of age. Despite its short lifespan, it grows quickly. The mature bark is tan with deep fissures, and the ridges twist and overlap, resembling thick hemp rope, exposing orange inner bark in the deep fissures. In mid-April and May, the Black Locust blooms with clusters of perfect, showy, and fragrant white flowers. The fruit is a light brown, thin pod about 4 inches long, containing several small, orange seeds; these pods ripen in the fall and often remain on the tree throughout winter. The pinnately compound leaves, sometimes called "sleeping leaves" because they fold up at night, are dark blue-green, smooth, nearly a foot long, and contain 7 to 19 leaflets. While these leaves sometimes turn yellow in the fall, they often remain green until frost kills them.