| australia | victoria | rhodocyclus | genus | 0 | 1 |
| brazil | parana | uncultured rhodocyclus sp. | species | 1 | 0 |
| china | | uncultured rhodocyclus sp. | species | 14 | 0 |
| germany | | rhodocyclus tenuis | species | 2 | 0 |
| japan | hokkaido prefecture | uncultured rhodocyclus sp. | species | 2 | 0 |
| japan | shizuoka prefecture | uncultured rhodocyclus sp. | species | 2 | 0 |
| united kingdom | | uncultured rhodocyclus sp. | species | 1 | 0 |
| united states | iowa | rhodocyclus purpureus | species | 71 | 0 |
| united states | massachusetts | rhodocyclus sp. hod 5 | species | 1 | 0 |
| united states | michigan | uncultured rhodocyclus sp. | species | 1 | 0 |
| uruguay | montevideo department | rhodocyclus | genus | 0 | 1 |