Hazelnut

hazelnut the fruit of hazel trees, of the genus Corylus, called noisette in French and nocciola in Italian. British and American nomenclature differ here. In Britain the term hazelnut can be applied whether the tree is wild or cultivated, while the names cob and filbert indicate two sorts of cultivated hazelnut. Americans, in general, reserve the name hazelnut for their wild species, and call their cultivated nuts, which are almost all descended from European species, filberts.

The common wild hazel of Britain, most of Europe, and SW Asia is Corylus avellana. It is a low, shrubby tree, up to 6 m (20') tall, which often forms part of a hedgerow. Its small nuts with their hard, brown shells are borne in clusters of one to four, within a husk whose fancied resemblance to a helmet accounts for the name Corylus, from the Greek korys (helmet). ‘Hazel’ itself comes from the Anglo-Saxon haesil (headdress).