Seventeen varieties of Hazel have documented use in Herbal Medicine: Corylus americana - American Hazel, Corylus avellana, Corylus avellana pontica, Corylus colurna - Turkish Hazel, Corylus cornuta - Beaked Hazel, Corylus cornuta californica - California Hazel, Corylus fargesii, Corylus ferox - Himalayan Hazel, Corylus heterophylla - Siberian Filbert, Corylus chinensis - Chinese Hazel, Corylus jacquemontii - Indian Tree Hazel, Corylus maxima, Corylus sieboldiana - Japanese Hazel, Corylus sieboldiana mandschurica, Corylus tibetica, Corylus x colurnoides - Trazel, Corylus x vilmorinii - Chinese Trazel