| Name | From | To | Age range |
|---|---|---|---|
| Alnus quaternaria | Late Cretaceous | Late Cretaceous |
|
| Alnus quinquepollenites | Late Cretaceous | Early Pliocene |
|
| Alnus raris | Late Pliocene | Late Pliocene |
|
| Alnus recollecta | Paleogene | Neogene |
|
| Alnus rhombifolia | Paleogene | Neogene |
|
| Alnus rubra | Paleogene | Neogene |
|
| Alnus rubriformis | Paleocene | Early Pliocene |
|
| Alnus rugosa | Tertiary | Early Pleistocene |
|
| Alnus scotia | Late Paleocene | Early Eocene |
|
| Alnus scotica | Late Paleocene | Early Miocene |
|
| Alnus serrulata | Early Tertiary | Neogene |
|
| Alnus sieboldiana | Early Tertiary | Early Tertiary |
|
| Alnus sp | Triassic | Quaternary |
|
| Alnus sp. Agra.et al,1956 | Early Oligocene | Early Oligocene |
|
| Alnus sp. Ande.,1960 | Maestrichtian | Paleocene |
|
| Alnus sp. Brat.,1966 | Paleocene | Paleocene |
|
| Alnus sp. Diac.& Nico.,1968 | Tortonian | Pannonian |
|