Hazelnut, also called "Cordoba hazel" is the fruit of the common hazel nut type (Corylus avellana). Abellana etymologically comes from the Latin nux, "Avella nut" Italian town of Campania. Spheroidal shaped with a diameter of approximately 10 to 15 mm. It consists of an outer fibrous shell surrounding a smooth cover in which the seed is housed. The dried fibrous husk during ripening.