Hornbeam, Carpinus, a small genus of deciduous trees belonging to the order Corylaceee.
C. betulus, the common hornbeam, our only native species, has smooth light, grey bark, which with its foliage resembles those of the beech; but the leaves are pointed and duller. Its timber is' dense, white, and tough, giving its name to the tree. It is used for wooden mill-cogs, and furnishes excellent fuel and gunpowder charcoal. American species, C. americana, is known as iron-wood, blue beech, or water beech.