Ostrya carpinifolia, the European hop-hornbeam, is a tree in the family Betulaceae. It is the only species of the genus Ostrya that is native to Europe.
Ostrya carpinifolia is a broadleaf deciduous tree, that can reach up to 24 metres (79 ft). It has a conical or irregular crown and a scaly, rough bark, and alternate and double-toothed birch-like leaves 3â10 cm long.
The flowers are produced in spring, with male catkins 5â10 cm (2â4 in) long and female catkins 2â5 cm (3â4â2 in) long. The fruit form in pendulous clusters 3â8 cm (1 1â4â3 1â4 in) long with 6â20 seeds; each seed is a small nut 2â4 mm (1â16â3â16 in) long, fully enclosed in a bladder-like involucre.