| Host genus | Fungal species | Symptoms and notes |
| Rhynchospora | Ustanciosporium gigantosporum | Ovary smut, causing dwarfing of infected shoots |
| Ribes | Puccinia ribesii-pendulae | Rust of stems and petioles; dubiously present in Britain due to morphologically similar species also reported from this host |
| Rosa | Elsinoë rosarum | Anthracnose spots on leaves and stems |
| Phragmidium rosae-pimpinellifoliae | Rust of stems and leaves, principally on Rosa pimpinellifoliae | |
| Phragmidium tuberculatum | Rust of leaves, on R. canina, R. rubiginosa, R. rugosa etc. | |
| Rubus | Elsinoë veneta | Anthracnose lesions of stems, causing death of the cane if uncontrolled. Primarily associated with R. idaeus and hybrids. |
| Kuehneola uredinis | Rust of leaves, petioles and stems | |
| Phragmidium rubi-idaei | Leaf rust of Rubus idaeus | |
| Phragmidium violaceum | Rust of leaves of Rubus fruticosus agg. | |
| Rumex | Puccinia phragmitis | Rust on leaves. Uredinia and telia on Phragmites |
| Ramularia pratensis | Causes leaf spot | |
| Ruscus | Phaeosphaeriopsis glaucopunctata | Associated with death of cladodes and dieback of shoots |