Locust is any of about 20 plants native to North America. Four of these are shade trees with heavily scented flowers. The others are shrubs. The trees sometimes grow about 80 feet (24 meters) tall.
In the United States, the black locust is the best-known locust tree. This medium-sized tree grows widely throughout the Eastern United States and southern Canada. It also is one of the most widely planted North American trees in Europe. Like most locusts, the black locust has prickly branches. Its fragrant white flowers hang in drooping clusters. The fruit of the locust tree consists of a long, glossy brown pod with about a dozen wax-coated seeds. Black locusts have blue-green compound leaves. The bark and leaves of the black locust are poisonous.
Locusts grow rapidly on good soil. On poor soils, locust borers kill the trees while they are still young. Another insect enemy, the leaf miner, may cause the leaves to turn yellow and fall off before the first frost.
Locust wood is commercially important because it is hard, lasts for a long time, and swells only slightly when wet. Locust trees make good fence posts and mine timbers.
