Native range: worldwide

Leaves:

• alternate
• simple
• ~doubly serrate margins

Flowers:

• monoecious
• male slender long catkins
• female upright or pendulous terminal spike
• flowers subtended by 2+ bracts

Fruit:

• nut (Corylus sp.) or samara (Alnus, Betula)

Other notes:

• deciduous trees or shrubs
• wind pollinated

Genera:

• Alnus (alder) | 1 species
• Betula (birch) | 1 species
• Carpinus (hornbeams) | 1 species
• Corylus (hazel) | 1 species