Carpinus is a genus of hardy, deciduous trees, grown largely for their foliage, which exhibits attractive, bright yellow, orange and red autumn colour. The leaves are alternate and simple, with serrated edges, usually measuring 3-10cm long. Flowers are borne in catkins during spring and lead onto small fruits 3-6mm long, which differ in seed wing shape across species. There are over 40 species and they tend to be located in the temperate Northern Hemisphere. Species in this genus are commonly termed hornbeams after the hardness of their wood.