HAZELNUT, or FILBERT, a genus (Corylus) of shrubs and trees of the family Betulacece, confined to the northern hemi sphere. The male flowers are in long cylindrical aments or catkins; and the fruit, a nut, is marked at its base with a large cicatrix. The inflorescences of the hazel are developed in the year preceding their appearance; the male flow ers last over the winter, naked; the female inflorescence is enclosed in a bud. In early spring the male catkins elongate andproduce an abundance of dry pollen, while the female inflorescences are distinguishable from the leaf buds only by their larger size and projecting red stigmas. The nut is enveloped at the base by a sheath of succulent bracts.
The European hazel (C. avellana), from cul tivation has produced several varieties, differing in the size, shape and flavor of the nuts, which are commonly known under the name of filberts. It grows in all situations and is easily culti vated, but a light and tolerably dry soil is the most suitable. The best nuts come from Spain, where they are baked in large ovens before export, in order to ensure their preservation. Other species occur in southern Europe and Asia. The American hazel (C. americana) very much resembles the European, but is lower in stature. It is common in most parts of the eastern United States, but has not been culti vated. A second species (C. rostrata) also
occurs in eastern North America and a third is found in California.
The oil which is obtained from hazelnuts by pressure is little inferior in flavor to that of almonds, and chemists employ it as the basis of fragrant oils artificially prepared and used by perfumers, because it easily combines with and retains odors. In•many parts of England hazels are planted in coppices and hedge-rows for sev eral useful purposes, but particularly to be cut down periodically for charcoal, poles, fishing rods, etc. In brewing, the dried twigs were used as a substitute for yeast when they were soaked in fermenting liquor. Being extremely tough and flexible, the branches are used for making hurdles, crates and springles to fasten down thatch. They are formed into spars, handles for implements of husbandry, and when split are bent into hoops for casks. Char coal made from hazel is much in request for forges, and when prepared in a particular man ner is used by painters and engravers to draw their outlines. The roots are used by cabinet makers for veneering; and in Italy the chips of hazel are sometimes put into turbid wine for the purpose of fining it. Finally forked twigs of the European hazel were formerly used by diviners to determine the position of water, gold, etc.