Riccia fluitans (Terrestrial Form)

Riccia fluitans, widely known as Crystalwort, is a cosmopolitan liverwort most familiar to aquarists as a buoyant surface plant or a tied-down foreground carpet in aquariums. In its terrestrial form, grown on consistently moist substrate or rock surfaces in the land zone of a paludarium, it forms a compact, densely branching mat of bright-green, strap-like thalli that spreads slowly across the surface without any rooting structure — absorbing moisture and nutrients directly through its lower surface.

The terrestrial form of R. fluitans offers a fine, jewel-green texture that complements mosses and other small liverworts in detailed paludarium land scaping. It grows best in areas with very high humidity and indirect light, avoiding positions that receive direct spray which can displace the lightweight thalli. It is not a true plant but a non-vascular liverwort, giving it some unique characteristics including the ability to desiccate and revive when moisture returns.

Light: Medium indirect; 1,000–2,500 lux; strong light causes browning; shade produces the best green colouration. CO2/Humidity: No CO2; humidity above 80% essential; keep the substrate surface continuously moist but not flooded. Fertilisation: Very light monthly misting with dilute all-purpose fertiliser; minimal nutrient requirements. Placement: Press onto moist substrate, rock surfaces, or damp cork bark in the land zone; it will spread naturally from there. Propagation: Tear small sections of the mat and press onto new moist surfaces; establishes within 1–2 weeks.