The locust is a tree which yields wood valuable in construction on account of its great durability in exposed positions. The eastern tree is called the black locust, while the tree in the western states is known as the mesquite. There is a slight difference between the two trees, but they belong to the same family. The wood is hard, heavy, and strong, reddish brown in color, and close-grained. It was largely used in the past for long wood pegs called tree-nails and is now used wherever great durability is required.