Locust
Locust, the common name for a number of trees and shrubs related to the carob. The black locust of the southern Appalachians is widely grown as an ornamental in the eastern United States and Europe. It grows as tall as 100 feet (30 m), with a trunk 4 feet (1.2 m) thick. The leaves are made up of oval leaflets growing from opposite sides of the leafstalks. A pair of spines grows from the base of each leaf, and spines grow also from the trunks of young trees. Large, drooping clusters of white, fragrant flowers occur on the tree in early spring. These are followed by flat, brown pods up to four inches (10 cm) long.
The black locust grows quickly, and its hard, heavy, strong wood is highly resistant to decay and shock. The wood is used to make insulator pins, for mine timbers, fence posts, and railway ties, and for rough construction.
The clammy locust of the Carolinas bears attractive pink flowers. It grows to a height of 40 feet (12 m). Its buds and other new growth are covered with sticky, clammy glands.
The bristly locust, or rose acacia, is a shrub that grows to 10 feet (3 m) in height. It has reddish bristles on its pods and stems. The showy flowers are deep rose to purple in color. The plant is native to the southeastern United States.
The black locust is Robinia pseudoacacia; clammy locust, R. viscosa; bristly locust, R. hispida. They belong to the pea family, Leguminosae.