Hazelnut, belongs to the family Corylus, which includes C. avellana (Common or European hazelnut) and the closely related species C. maxima (filbert). Hazels are deciduous trees or shrubs in the family Betulaceae grown for their edible nuts. Hazelnuts are large multi-stemmed shrubs or small trees with rounded leaves which possess a doubly serrated margin (each tooth bears another tooth). They produces flowers very late in the winter prior to the emergence of any leaves. The female flowers are small and only the bright red stigmas are visible protruding from the bud. The male flower is a catkin which is pale yellow in color and measures 6–12 cn (2–5 in) in length. The fruit of the hazelnut is a classic nut which grows in clusters of 1–5, each protected by a leafy husk which covers most (common) or all of the nut (filbert). The nut is oval in shape and yellow to brown in colour. Each has a pale scale at its base. When ripe, the nut falls from the husk to the ground. Hazenut can reach a height of 3–8 m (10–26 ft) and can live for many years, although its commercial lifespan is usually about 40 years. Hazelnut originates from Europe and South East Asia.