| alnus incana subsp. rugosa | | USA: District of Columbia; United States Botanic Garden, 100 Maryland Ave SW. | | 1243026429 |
| alnus incana subsp. rugosa | | USA: District of Columbia; United States Botanic Garden, 100 Maryland Ave SW. | | 1243025123 |
| alnus incana subsp. rugosa | | USA: District of Columbia; United States Botanic Garden, 100 Maryland Ave SW. | | 1243023342 |