Corylus heterophylla

Corylus heterophylla, the Asian hazel, is a species of hazel native to eastern Asia in northern and central China, Korea, Japan, and southeastern Siberia. It is a deciduous shrub or small tree growing to 7 m (23 ft) tall, with stems up to 20 cm (8 in) thick grey bark. The leaves are rounded, 4–13 cm (1 1⁄2–5 in) long and 2.5–10 cm (1–4 in) broad, with a coarsely double-serrated to somewhat lobed margin and an often truncated apex. The flowers are wind-pollinated catkins; the male (pollen) catkins are pale yellow, 4 cm (1 1⁄2 in) long, while the female catkins are bright red and only 1–3 mm (1⁄16–1⁄8 in) long. The fruit is a nut produced in clusters of 2–6 together; each nut is 0.7–1.5 cm (1⁄4–1⁄2 in) diameter, partly enclosed in a 1.5–2.5 cm (1⁄2–1 in) long, bract-like involucre (husk). It is very similar to the closely related common hazel (C. avellana) of Europe and western Asia, differing in the leaves being somewhat more lobed. The nut is edible, and is very similar to the common hazel nut; it is cultivated commercially in China.