| Kingdom: Fungi |
| Phylum: Ascomycota |
| Subphylum: Pezizomycotina |
| Class: Dothideomycetes |
| Subclass: Dothideomycetidae |
| Order: Incertae sedis |
| Family: Botryosphaeriaceae |
| Genus: Diplodia |
| Subject: Diplodia tumefaciens (Shear) Zalasky |
| Kingdom: Plantae |
| Phylum: Magnoliophyta |
| Class: Magnoliopsida |
| Subclass: Dilleniidae |
| Order: Salicales |
| Family: Salicaceae |
| Genus: Populus |
| Subject: Populus tremuloides Michx. |