Hazel is a nut tree of the family Betulaceae and Corylus 1inn. It has about 20 species in the world and is widely distributed in temperate regions of Asia, Europe and North America. There are nine species recognized by academia, namely, C. America, C. avellana, C. colurna, etc., but only genuinely edible value is Corchorus. There are 8 species and 2 variants in China, which are mainly distributed in the mountains of the three northeastern provinces, the northern provinces of China, the Hengduan Mountains in the southwest, and Gansu, Shaanxi and Inner Mongolia in the northwest.
Round hazelnut
This kind of hazelnut, as its name suggests, is similar in shape to a circle. Round hazelnuts have the best quality. Compared with sharp hazelnuts, round hazelnuts have a high content of oil, a unique flavor and taste. The main types of such hazelnuts are called "Round", "Palaz", "Mincane", "Fosa", "Kara Findik".
Sharp hazelnut
These hazelnuts are slightly longer in shape, have lower oil content than round hazelnuts, and are difficult to remove. Most produced in the provinces of Giresun and Trabzon, according to the Giresun quality of the sharp hazelnuts are considered to be the best.
The rest are produced in other provinces. The other (long-circle) of such hazelnuts is considered badem, (almond shape).
In addition to these important varieties, there is also a round hazelnut "FOSA" which is generally larger than the others and which occupies a special position in the "shell" hazelnut trade.