HAZEL, Corylus, a genus of trees and shrubs of the natural order cupviiferm, of which the fruit is a nut in a leafy and laciniated cup, the enlarged involuere of the female flower. The male flowers are in cylindrical catkins; the female flowers appear as mere clusters of colored styles at the extremities of buds; the male flowers are pretty conspicuous, the female flowers are very small.—The COMMON HAZEL (C! arcllana.) is a large shrub or low tree, with a bell-shaped fruit-cap, which is somewhat two-leaved, open, and spreading. It is a native of Britain, and of all the temperate parts of Europe and Asia; it is common also in North America. Ilazel nuts of improved varieties are grown to a considerable extent in the south of England, particularly in Kent; they are also imported in large quantities frotn the south of Europe. Hazel nuts yield, on pressure, about half their weight of a bland fixed oil, often call nut-oil in Britain, the hazel-nut being popularly known by the term nut alone; but in Germany it is walnut-oil which is usually called nut-oil. Hazel-nut-oil has drying properties, and is much used by painters; it is also used by perfumers as a basis with which to mix expensive fragrant oils; and it has been employed medicinally in coughs. The wood of the hazel, although seldom large enough for the purposes of the carpenter, is very tough and flexible, and hazel rods are therefore much used for making crates, hurdles, hoops for small barrels, etc. The thicker stems of hazel are used for making charcoal, which is in great request for forges, is much esteemed for the manufacture of gunpowder, and is the kind preferred by artists for crayons.
The value of the hazel-nuts annually imported into Britain is about £100,000. The quantity used for making oil is comparatively inconsiderable.
Most of the cultivated varieties of the hazel-nut are known by the names of cob-nuts and filberts; the former generally of a roundish form; the latter characterized by the greater elongation and laciniation of the fruit-cup; the name filbert being indeed regarded as a corruption of full-beard. The Red filbert, or Lambert's nut., is remark able for having the pellicle which surrounds the kernel of a crimson-red color. The finer kinds of hazel are propagated by grafting and by layers. Hazel plants for copses are obtained from seed.—The NEARED HAZEL (C. rostrata), a species having a very hairy fruit-cup prolonged into a long beak, is a native of the northern parts of America. Its kernel is sweet.—The CONSTANTINOPLE HAZEL (C. colurna), the nuts of which are considerably larger than those of the common hazel, is a native of the Levant, from which the fruit is imported into Britain. It is much used for expressing oil, hut is a less pleasant fruit than many kinds of cob-nut and filbert. A IIhnalayan species of Hazel (C. ferox) has a spiny fruit-cup, and an excessively hardnut. Barcelona sluts are the nuts of a variety of the COMIDOil hazel, kiln-dried before their exportation from Spain. Ihzel-nuts not subjected to this procest cannot be kept long Without losing in part their agreeable flavor, and contractino. a sensible rancidity, except in air-tight vessels, in which they are said to remain fresh even for years.
The larva of a weevil (balaninta nucum) feeds on the kernels of hazel-nuts. The parent female makes a hole into the nut by means of her long snout and there deposits an egg. Great numbers of nuts are thus destroyed.