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 3–10 cm long.
The flowers are produced in spring, with male catkins 5–10 cm (2–4 in) long and female catkins 2–5 cm (3⁄4–2 in) long. The fruit form in pendulous clusters 3–8 cm (1 1⁄4–3 1⁄4 in) long with 6–20 seeds; each seed is a small nut 2–4 mm (1⁄16–3⁄16 in) long, fully enclosed in a bladder-like involucre.
