The genus Ostrya of the birch family, represented in North America by two species. Ostrya virginiana is widely distributed in the eastern half of the United States and in the highlands of southern Mexico and Guatemala. It can be recognized by its fruit, which closely resembles that of the hop vine, and by its very scaly bark. The scales usually occur in narrow, more or less parallel, vertical strips. The leaves are sharply and doubly serrate. This is one of several trees known as ironwood because of its hard, strong wood; it is used for fence posts, tool handles, mallets, and other articles requiring hardness and strength. Ostrya knowltonii is a small rare tree of the southwestern United States.