Ecology Distribution Management Info Impact Info References and Links Contacts

General Impact Azolla pinnata can spread very quickly forming dense vegetative masses on areas of still water. This in turn limits light available to other aquatic plants and oxygen used by other aquatic life. It forms dense mats that choke out other species. A. pinnata is on the US noxious weed list. In New Zealand has replaced a native floating fern, Azolla rubra, over most of northern New Zealand. Azolla lives in symbiosis with blue-green algae (cyanobacteria), taking advantage of their ability to fix nitrogen. It is sometimes introduced and used by farmers as a natural fertilizer for this reason.          Location Specific Impacts: New Zealand   Competition: Azolla pinnata has replaced a native floating fern, Azolla rubra, over most of northern New Zealand (Owen, 1997).