AquaNISInformation system on aquatic non-indigenous and cryptogenic species |
Species | Azolla filiculoides | |
Authority | Lamarck | |
Family | Azollaceae | |
Order | Hydropteridales | |
Class | Filicopsida | |
Phylum | Pteridophyta | |
Synonym (?) | ||
Sub-species level (?) | Not entered |
Native origin (?) | Not entered |
Life form / Life stage (?) |
Comments: A. filiculoides is a small aquatic heterosporous fern. A. filiculoides in its native areas (South America and western North America) is a plant of slow flowing streams and rivers, ponds and lakes. |
Sociability / Life stage (?) | Not entered |
Reproductive frequency (?) | Iteroparous References (not structured): Lumpkin TA, Plucknett DL (1982) Azolla as a green manure: use and management in crop production. Azolla as a green manure: use and management in crop production. Westview Press Boulder, Colorado, 230pp. Comments: A. filiculoides is able to undergo rapid vegetative reproduction throughout the year by the elongation and fragmentation of the small fronds, and under ideal conditions, the daily rate of increase can exceed 15% with the doubling time being every 4-5 days |
Reproductive type (?) | Asexual Sexual References: Ashton PJ (1982) The autecolgy of Azolla filiculoides Lamarck with special reference to its occurrence in the Hendrik Verword Dam catchment area. Dissertation, University of Rhodes, South Africa Comments: Under favourable environmental conditions, A. filiculoides undergoes sexual reproduction.Pairs of sporocarps are formed from a ventral lobe initial of a lateral branch. The sporocarps are of two types, male microsporocarps and female megasporocarps. A. filiculoides propagates both asexually and sexually. |
Developmental trait (?) | Resting stages References: Moore AW (1969) Azolla: biology and agronomic significance. Botanical Review, 35:17-35 Comments: Upon reaching maturity, both micro- and megasporocarps dehisce. Microsporangia release spongy masses of massulae into the water, which attach to megasporocarps via barbed, protruding appendages (glochidia).These entanglements usually sink to the bottom of a water body and, after a period of dormancy, the micro- and megaspores will germinate to form prothalli. Ciliated, male gametes (antherozoids) develop in antheridia on the male thallus and female gametes (oospheres) develop in archegonia on the female thallus. After fertilization of the oospheres by the antherozoids, an embryo develops. |
Characteristic feeding method / Life stage (?) | Not entered |
Mobility / Life stage (?) | Not entered |
Salinity tolerance range (?) | Not entered |
Habitat modifying ability potential (?) | OLD VALUE References: Hill MP (1997) The Potential for the Biological Control of the Floating Aquatic Fern, Azolla filiculoides Lamarck (red water fern / rooivaring) in South Africa. Report No. KV 100/97. Pretoria, South Africa: Water Research Commission. McConnachie AJ (2003) Post release evaluation of Stenopelmus rufinasus Gyllenhal (Coleoptera: Curculionidae) - a natural enemy released against the red waterfern, Azolla filiculoides Lamarck (Pteridophyta: Azollaceae) in South Africa. Dissertation, University of the Witwatersrand, Johannesburg, South Africa Comments: --/OLD VALUE/-- Seasonal habitat former A. filiculoides infestations may form thick mats (5-20 cm thick), on water bodies up to 10 hectares in size. Such infestations have been shown to severely impact the biodiversity of aquatic ecosystems and have serious implications for all aspects of water utilization. In eutrophic water systems, A. filiculoides grows rapidly, easily outcompeting indigenous vegetation. Decaying root and leaf matter below a mat of A. filiculoides, and the lack of light penetration, creates an anaerobic environment. Not only can very little survive under such conditions, but the quality of drinking water is reduced, caused by bad odours, colour and turbidity. Cases have been reported where both livestock and game farmers have lost animals due to them refusing to drink from infested water bodies or drowning as a result of mistaking the mat for solid ground. The weed also reportedly increases water loss through evapotranspiration and promotes the development of waterborne, water-based and water-related diseases. |
Toxicity / Life stage (?) | Not relevant |
Bioaccumulation association (?) | Not entered |
Known human health impact? | Not entered |
Known economic impact? | Not entered |
Known measurable environmental impact? | Not entered |
Included in the Target Species list? | Not entered |
Association with vessel vectors (?) | Not entered |
Last update by | Aleksas Narščius, 2012-10-08 |