The botanical name for the genus, Carpinus, is the original Latin name for the European species, although some etymologists derive it from the Celtic for a yoke.

[2] Hornbeams are small, slow-growing, understory trees with a natural, rounded form growing 4.5–9 metres (15–30 feet) tall and wide; the exemplar species—the European hornbeam—reaches a maximum height of 32 m (105 ft).

[3]: 296 Leaves are deciduous, dark-green, alternate and simple with a coarsely-serrated margin, varying from 3 to 10 centimetres (1 to 4 inches) in length.

[4] The smooth, gray trunk and larger branches of a mature tree exhibit a distinctive muscle-like fluting.

[5] As with other members of the birch family, hornbeam flowers are wind-pollinated pendulous catkins, produced in spring.

[7][8] Formerly some taxonomists segregated them with the genera Corylus (hazels) and Ostrya (hop-hornbeams) in a separate family, Corylaceae.

[12] Hornbeams are used as food plants by the larvae of some Lepidoptera species, including autumnal moth, common emerald, feathered thorn, walnut sphinx, Svensson's copper underwing, and winter moth (recorded on European hornbeam) as well as the Coleophora case-bearers C. currucipennella and C.