The hazel tree is a deciduous tree or shrub belonging to the genus Corylus. It typically grows to a height of 10 to 20 feet and is known for its rounded leaves and catkins, which are long, cylindrical flower clusters. The tree produces edible nuts called hazelnuts, which are popular in cooking and baking. Hazel trees thrive in well-drained soil and prefer sunny to partially shaded areas. They are commonly found in temperate regions of Europe, Asia, and North America. In addition to their nuts, hazel trees are valued for their flexible branches, which are often used in traditional crafts and basketry.