Hazels (Corylus Avellana) are shrubs and small trees, native to Europe and Western Asia. It is about 12′ to 15′ tall, having simple, rounded leaves with double-serrate margins. The flowersin hazel plant are produced very early in spring, before the leaves, which are monoecious with single-sex wind-pollinated catkins. 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. A form of edible oil known as ‘hazel nut oil’ is extracted from these nuts which is widely used for culinary as well as medicinal purposes. Hazelnut plants are commercially cultivated in the orchards of Europe, Turkey, Iran and Caucasus.