Related Clues:
- Bit of aquarium scum
- Aquatic organism such as plankton
- Bit of 19-Across flora
- Bit of birdbath gunk
- Simple marine plant
- Tangle of small spawn noted by Spooner in the Firth?
- Wee bit of marine life
- Pond scum organism
- Small bit of rootless flora
- Fountain growth
- Marine plant ending in trouble in river, was surfacing
- Bit of 30-Down life
- Bit of fish tank growth
- Outer layer of some rolls
- Tiny lake organism