Betulaceae, or the Birch Family, includes two genera of trees and shrubs, the birches and the alders. The family is often treated as also including the Corylaceae: hazels, hornbeams and hop-hornbeams.

Example species of the three genera are:

• Alnus - alder
  • Black alder Alnus glutinosa
  • Speckled alder Alnus incana
  • Red alder Alnus rubra
  • Green alder or Mountain alder Alnus viridis
• Betula - birch
  • Silver birch Betula pendula
  • Paper birch Betula papyrifera
  • River birch Betula nigra

Fagales