Propagating Riccia fluitans 'Sunset' by Division

How to multiply Riccia fluitans 'Sunset', a rootless floating liverwort, by dividing the clump and tying thin pieces under mesh for a pearling carpet.

Overview

Riccia fluitans 'Sunset' is a colour selection of Riccia fluitans, an aquatic floating plant of the liverwort genus Riccia. The 'Sunset' form takes on golden-yellow tones under bright light, while the wild species forms dense, bright green mats on and below the water surface.

Riccia lacks roots entirely. It naturally floats, but it can also be attached to underwater objects such as logs and rocks, which is how aquarists create the classic pearling lawn that gives off streams of oxygen bubbles under strong light.

Propagation Method (Division)

Because Riccia has no roots and no stems to cut, you propagate it by division: simply pulling or splitting the floating clump into smaller pieces. Any single branch or antler bud can reproduce into a large colony, so even small fragments will grow into new mats under suitable conditions.

Step-by-Step

Lift a healthy floating clump of 'Sunset' Riccia from the tank.
Pull or split it into several smaller pieces with your fingers.
To carpet a surface, spread a thin layer of Riccia over a stone or piece of wood and hold it down with plastic mesh or fine thread.
Alternatively, leave divided pieces to float freely so they form new mats at the surface.
Place the tied surfaces under bright light so the colony fills in and develops golden tones.

Conditions for Healthy Growth

Riccia develops dense, bright green mats when positioned close to strong light such as bright fluorescent bulbs or full sunlight; the 'Sunset' selection colours up best under high light. The plant grows quickly at the surface under proper conditions.

Light: high — essential for compact growth and pearling.
Position: 2-3 inches (a few centimetres) below the light source, or attached low for a submerged carpet.
Growth: fast under strong light.

Maintenance

Tied-down Riccia grows outward and upward, so trim and re-thin the carpet regularly to keep it attached and tidy; the trimmings can be re-tied or left to float as new starts.

Common Challenges

Riccia is vulnerable to hair algae overgrowth, especially in strong light, so keep nutrients balanced and water clean. It is also incompatible with duckweeds, which compete for the same surface space; avoid mixing the two.