Azolla filiculoides: is a member of the Azollaceae and is a small, free-floating, aquatic fern. The species is commonly known as Azolla.
The fronds are green to dark red in colour. The dark red colour is triggered by cold nights or exposure to full sun. Roots hang down in the water.
Azolla forms dense mats and may cover ponds, dams and lagoons. The species is used on ponds and dams as cover for fish. It is not palatable to fish.
Azolla occurs in all states, except the Northern Territory, as well as New Zealand, South Africa, The Americas and Europe.
Propagate by transferring clumps of Azolla from one body of water to another.