The open plant encyclopedia
Snap a photo or search by any name to see how to care for it, where it comes from, whether it's safe, and a 3D model you can turn.
The plants people record most in your country, and ones that grow there wild.
Filter by what you want to do, shape, origin, country, care and safety.
Azolla caroliniana
Also called Fairy Moss, Mosquito Fern, Mosquito Plant, Carolina Mosquito Fern, Water Velvet
Carolina mosquito fern (Azolla caroliniana) is a tiny free-floating freshwater fern that forms a velvety green mat on still water. The key to growing it is steady warmth, plenty of sunlight, and calm water.
Azolla cristata, the Carolina mosquito fern, Carolina azolla, or water velvet, is a species of the Azolla genus native to the Americas, in eastern North America from southern Ontario southward, from the east coast west to Wisconsin and Texas, the Caribbean, and in Central and South America from southeastern Mexico (Chiapas) south to northern Argentina and Uruguay.
It is a freshwater aquatic fern, with scale-like fronds 5–10 mm long, green to reddish, most often reddish in winter and in strong light. They are covered in tiny trichomes that give it the appearance of velvet. It is able to fix nitrogen from the air by means of symbiotic cyanobacteria. It can survive winter water temperatures of 5 °C (41 °F), with optimum summer growth between 25–30 °C (77–86 °F).
A. cristata is of commercial importance in cultivation in southern and eastern Asia as a biofertilizer, valued for its nitrogen-fixing ability, which benefits crops such as rice when the fern is grown under it and reduces the need for artificial fertilizer. The thick mat of fronds (up to 4 cm thick) also suppresses weed growth. Harvested fronds are also used as a food for fish and poultry. It is also often used as a floating plant in both coldwater and tropical aquaria, as well as in outdoor ponds; it is propagated by division.
Pacific mosquitofern · Mexican mosquitofern · Azolla nilotica · Feathered mosquitofern · Azolla primaeva · Mosquitofern
Text excerpted from the Wikipedia article Azolla cristata by its contributors, under CC BY-SA 4.0; the excerpts and the care summary drawn from them are shared under the same licence.
The care summary was written by AI (Claude, Anthropic) from the sources on this page, with general growing knowledge where they are silent. Check before relying on it.
Life form, climate and native range: World Checklist of Vascular Plants, Royal Botanic Gardens, Kew (CC BY 3.0), reformatted; see Plants of the World Online.
