Hazelnut bush

A plant species from the birchfamily (Betulaceae), which is also known colloquially as the hazel bush or hazelnut bush. It grows as a small tree or shrub and can reach a height of up to 6 meters. The hazelnut bears male and female inflorescences on the same plant (asexual) and is pollinated by the wind. The male flowers are the 4-8 cm long hanging catkins.

Corylus avellana is the parent plant of:

• Folia Coryli avellanae(INCI name: Corylus avellana extract), the extract from the leaves of the hazel bush. Ingredients are 0.04% essential oil, taraxerol, beta-sitosterol.
• Folia Coryli avellanae is used under the INCI name Corylus avellanae extract (INCI) in cosmetic products as a skin care product
• Cortex Coryli avellanae is the extract from the bark of the hazel bush.
• Oleum Coryli avellanae(INCI designation Corylus avellana nut oil), the hazelnut oil, is the fatty oil from the hazelnut kernels. It contains about 85% oleic acid glycerol ester and 10% palmitic acid glycerol ester.
• Allergologically hazelnut allergens play an important role (see hazelnut allergy, see also tree pollen).

Hazel bushes grow preferentially on the edges of forests, but also form hedges in fallow land. They need nutrient-rich, loamy soil and plenty of light. The hazelnut is common in the northern hemisphere with 15 species; in the Alps it can be found up to an altitude of 1800 m.

1. Etesamifar M, Wüthrich B (1998) IgE-mediated food allergies in 383 patients under consideration of the oral allergy syndrome Allergology 21: 451-457
2. Fuhrman C et al (2007) Short-term effect of pollen exposure on antiallergic drug consumption. Ann Allergy Asthma Immunol 99: 225-231
3. Hofer Th, Wüthrich B (1985) Food allergies. II. Frequency of organ manifestations and allergy-causing foods. Switzerland Med Weekly 115: 1437-1442