Plants in the genus Carpinus (Cár-pi-nus) are commonly calle Hornbeams. They are relatively small hardwood trees. Many botanists place the hornbeams in the birch family Betulaceae, though some group them with the hazels (Corylus) and hop-hornbeams (Ostrya) in a segregate family, Corylaceae. The 30-40 species occur across much of the north temperate regions, with the greatest number of species in east Asia, particularly China. Only two species occur in Europe, and only one in eastern North America.