Hazel is a large shrub or small tree which grows in hedges and thickets throughout Britain.
The male catkins appear in January or even earlier, initially small and brown, then becoming paler and woollier, when they are known as "lamb's tails". Later they open and turn yellow with pollen, which is carried on the wind to the female flowers. These are tiny crimson star-shaped flowers situated at the tips of the shoots, with tufts of protruding crimson stigmas when mature.
The brown nuts occur in clusters in autumn, each enclosed by a leafy husk. The familiar edible hazel nuts (or "cobnuts") are cultivated varieties.
Hazel used to be more common, as it was coppiced for practical uses such as hedge laying. The thicker stems provide rods to form the upright posts, while the flexible thinner stems are used for weaving.

Male catkins, and small female flowers on tip of stem		Hazel leaves, and mature female flowers with protruding crimson stigmas

Ripe hazel nuts		Unripe hazel nuts

Early catkins (autumn)		Lamb's tails (January)		Longer catkins

Male flowers		Female flowers and hairy stem