Azolla Caroliniana is a floating plant. This very small floating fern has very small scaly leaves with two-celled hairs on them.
AZOLLA (Azolla caroliniana) - Green, mossy, fern-like, floating carpet. Rampant grower. Azolla caroliniana, also known as mosquito fern, is a floating, aquatic fern native to the eastern and southern United States. In its natural habitat, A. caroliniana can be found covering the surfaces of ponds, lakes and swamps. Due to its fast growing tendencies, Azolla caroliniana is infrequently used for aquariums. It can be obtained from most of the major aquatic nurseries, nonetheless.
Azolla caroliniana is a very undemanding plant for the home aquarium, requiring only moderate lighting to thrive. It is also very hardy in nature as the spores of the plant can easily survive cold weather and freezing temperatures. An interesting note is its symbiotic relationship with Anabaena, which are found in small cavities at the base of each leaf. Anabaena is a blue-green algae able to obtain nitrogen from the air and fix it in a way that makes it available for use by its host, A. caroliniana. For this reason, this small floating plant is often grown in rice fields and used as an agricultural fertilizer due to its high nitrogen content.
Pruning and propagation of A. caroliniana is very simple. To prune, simply scoop up all the undesired plants and discard in a safe manner (due to A. caroliniana's invasive tendencies, it should not be allowed to enter local waterways). Propagation is effortless --simply allow this fern to spread along the water's surface.
Depending on light conditions, this plant may be either red or a strong red. Both are beautiful and make wonderful additions to open top aquariums, bowls, and water gardens. They are great, attractive nutrient absorbers and the roots make excellent and attractive cover for fry.