Description

The Ricciaceae are liverworts, rootless plants without vascular tissue, related to mosses. In the aquarium the family is represented by Riccia fluitans, which forms floating masses of branching green ribbons. It is used as surface cover or tied to a stone to form cushions, and in that case it needs frequent trimming and re-tying, because it does not attach on its own.
RicciaFluitansAgg

Riccia

Image byChristian Fischeris licensed under CC BY-SA 3.0 (resized)