| Malva | Puccinia malvacearum | Rust of leaves and stems |
| Melica | Colletotrichum sp. P2579 | Apparently causing necrosis of leaves of Melica uniflora |
| Mentha | Puccinia menthae | Rust of leaves and stems |
| Mercuralis | Cercospora mercurialis | Causes leaf spots |
| Melampsora rostrupii | Rust of leaves and petioles | |
| Myrrhis | Puccinia chaerophylli | Rust of leaves and petioles |