Topic summary
Common hazel

Extracted from the Wikipedia article Corylus avellana.
Description
Common hazel is typically a shrub reaching 3–8 metres (10–26 feet) tall, but can reach 15 m (49 ft). The leaves are deciduous, rounded, 6–12 centimetres (2+1⁄2–4+1⁄2 inches) long and across, softly hairy on both surfaces, and with a double-serrate margin. The flowers are produced very early in spring, before the leaves, and are monoecious with single-sex wind-pollinatedcatkins. Male catkins are pale yellow and 5–12 cm long, while female flowers are very small and largely concealed in the buds with only the bright red 1–3 millimetres (1⁄16–1⁄8 in) long styles visible. The fruit is a nut, produced in clusters of one to five together, each nut held in a short leafy involucre ("husk") which encloses about three-quarters of the nut. The nut is roughly spherical to oval, 15–20 mm (5⁄8–3⁄4 in) long and 12–20 mm (1⁄2–3⁄4 in) broad (larger, up to 25 mm long, in some cultivated selections), yellow-brown with a pale scar at the base. The nut falls out of the involucre when ripe, about 7–8 months after pollination.