It is a small to medium tree reaching 15-25 m, rarely 30 m, with a sinuous trunk. The bark is thick, greenish-grayish, even in the old ones (see photo): it resembles that of the beech, but often has ribs. The shoots, unlike Fagus, are no more than 1 cm long, and pressed towards the wings. The leaves are alternate, 4-9 cm long, with prominent veins giving a distinctive corrugation, and serrate margins and resemble those of elm, but are symmetrical (see photo). The buds are alternate and tapering (see photo), but less so than those of beech. Male and female flowers are borne separately in spring. The male flowers, grouped in catkins, facilitate wind pollination. The fruit is a small, long nut, 7-8 mm long, partially enveloped by trifoliolus, the involucre 3-4 cm long; it ripens in autumn. Seeds often do not germinate until spring of the second year after sowing. It is a prolific seed-bearer and has vigorous natural regeneration.