Hazelnut (Corylus) is a biological genus in the family Betulaceae (Alder) and order Fagales.
Corylus cornuta
Corylus avellana
Corylus chinensis
Corylus americana
Corylus ferox
Corylus heterophylla
Corylus colurna
Alnus
Betula
Corylus
Ostrya
Carpinus