Species: Butt-tjernaks (Potamogeton obtusifolius)
| Site | Municipality (county) | Num. obs. | Num. species | Num. images | Last obs. | |
|---|---|---|---|---|---|---|
| Frøylandsvatnet | Rogaland, Norway | 1 | 1 | 0 | 1992-10-05 | |
| Longvatnet | Rogaland, Norway | 1 | 1 | 0 | 1989-09-06 | |
| Øvre Storfjordvatnet | Nordland, Norway | 1 | 1 | 0 | 1989-09-01 |