 |
|
|
||||
| NAS - Nonindigenous Aquatic Species |
Translate this page with 
Common Name: feathered mosquitofern
Taxonomy: available through 
Identification:
Free floating aquatic plant typically found in clusters or in large mats. Each plant is 1-2.5 cm in diameter with a triangular shape; midsection is typically straight with pinnately arranged side branches that are longer towards their base. Roots and fine lateral root hairs appear feathery in the water. Each leaf is 1-2 mm long and overlap in a two-ranked pattern.
Plants reproduce vegetatively and sexually. Vegetative fragments form when the main axis deteriorates and lateral branches break free. When reproducing sexually, round sporocarps (1-1.5 mm in diameter) form on the underside of the leaves.
Color ranges from green to maroon-red. Red hues form when anthocyanin is produced as a reaction to unfavorable pH, temperature, moisture or nutrient availability (Holm et al 1997).
*** Identification of this and many Azolla spp is notoriously difficult, requiring detailed examination of sporocarps and other features.
Native Range:
Africa and Madagascar, India, Southeast Asia, China and Japan, Malaya and the Philippines, the New Guinea mainland and Australia.
| ||
 Alaska |
Hawaii |
Caribbean |
Interactive maps: Continental US, Alaska, Hawaii, Caribbean
Nonindigenous Occurrences:
1n 1999, this federally listed noxious weed was first confirmed in a water garden store in Raleigh, North Carolina (Kay and Hoyle 2000). Surveys conducted in 2002 by the Arizona Department of Agriculture found A. pinnata in multiple stores that sell aquatic plants for ponds or aquariums, but not in any natural or man-made waterways. In late 2007, it was confirmed in a display tank for aquatic plants at a lawn and garden center in Ada County, Idaho. Officials from ID Dept. of Agriculture and APHIS determined the plants from this tank had not been sold to customers; the retail store is contacting its suppliers to notify them of the issue (T. Woolf, ID Dept. of Ag., pers. comm. 2007). Most recently found in a drainage canal near Jupiter (Palm Beach County), Florida (Ferriter et al 2008).
Ecology: Upper lobes of A. pinnata's leaves are host to a cyanobacteria symbiont that fixes atmospheric nitrogen. It is sometimes introduced by rice farmers as a natural fertilizer for this reason. Typical habitats are wind-protected, slow-moving waters, such as ponds, small lakes, swamps, wetlands or drainage canals.
Means of Introduction: The main pathway in the U.S. is hitchhiking with ornamental pond or aquarium plants. In other countries it has also been introduced by farmers to help fertilize rice fields (Holm et al. 1997, PIER 2007).
Status: Federal Noxious Weed
Impact of Introduction: It forms dense surface mats, which interfere with boating, fishing and recreational activities as well as degrade water quality by reducing oxygen levels and limiting light to native plants.
Remarks:
References
Other Resources:
Author: V. Howard
Revision Date: 1/29/2008 Citation for this information:
V. Howard. 2009. Azolla pinnata. USGS Nonindigenous Aquatic Species Database, Gainesville, FL.
<http://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=2745> Revision Date: 1/29/2008
| AccessibilityFOIAPrivacyPolicies and Notices | |
  |
|