South American Willow Moss

Despite its common name, Fontinalis antipyretica has a holarctic distribution across Europe, North America, and parts of Asia, growing in cold, fast-flowing, oxygen-rich streams. Its long stems bearing overlapping, keeled leaves create a dense, bush-like effect on submerged wood and stones. It is one of the hardiest aquatic mosses and can survive very low temperatures, making it excellent for temperate and unheated aquariums.

Light: low light; prefers reduced light to avoid algae growth on its long stems. CO2: not required; performs well in cool, well-oxygenated water without injection. Attachment: tie loosely to driftwood or wedge between rocks; high flow rates help anchor it naturally. Trimming: thin out dense clumps periodically to maintain water circulation through the mass. Growth: moderate; propagate by cutting stems and securing cut ends to hardscape.