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A1741 Azolla filiculoides - Azolla microphylla Aquatic Vegetation Alliance
Type Concept Sentence: This is freshwater aquatic herbaceous alliance is dominated by Azolla filiculoides and/or Azolla microphylla floating on the water''s surface and occurs in freshwater habitats with still water. Ponds supporting this alliance can be found in warm climes such as California''s Central Valley and cool climes in montane ponds throughout western Canada and the western U.S.
Common (Translated Scientific) Name: Pacific Mosquito Fern - Mexican Mosquito Fern Aquatic Vegetation Alliance
Colloquial Name: Western Mosquito Fern Aquatic Vegetation
Hierarchy Level: Alliance
Type Concept: This is a widespread, aquatic herbaceous alliance that occurs in freshwater ponds with still water. The vegetation of this alliance is dominated by Azolla filiculoides and/or Azolla microphylla floating on the water''s surface. Other species present may include Lemna gibba, Lemna minor, Spirodela spp., Wolffia borealis, and other Wolffia spp. Emergent plants may be present. Total cover may be continuous, intermittent or open. Stands occur in seasonal and perennial wetlands in ditches, rivers, streams, channels, and ponds from sea level to 2300 m (7545 feet) elevation.
Diagnostic Characteristics: Azolla filiculoides and/or Azolla microphylla are dominant, floating on the water''s surface, or high abundance with other floating species.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: While commonly seen, this alliance has not been well-sampled. Azolla mats occur throughout California where conditions are favorable. Mats of both Azolla and Lemna occur under the same conditions, and either can dominate in the same waterbody.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This is a floating hydromorphic-rooted alliance that is characterized by low-statured (less than 5 cm) floating herbs with continuous to open coverage of the water''s surface.
Floristics: This alliance is dominated by Azolla filiculoides and/or Azolla microphylla (= Azolla mexicana) floating on the water''s surface. Other species present may include Spirodela spp., Lemna gibba, Lemna minor, Wolffia borealis, and other Wolffia spp. Emergent plants may be present. Total cover may be continuous, intermittent or open.
Dynamics: This alliance grows in still ponds that may dry up completely between seasons. Azolla spp. require standing water to germinate, and once an individual plant is established, it can quickly spread via asexual reproduction. If the water persists long enough, sexual reproduction produces cysts or spores which can survive drawdown and drying of the substrate.
Environmental Description: This widespread aquatic herbaceous alliance occurs in freshwater habitats with still water. Stands occur in seasonal and perennial wetlands in ditches, rivers, streams, channels, and ponds from sea level to 2300 m. It occurs in warm climes such as the Central Valley of California as well as montane ponds.
Geographic Range: This alliance is found in lowlands as well as montane ponds in California, Oregon and Washington and is likely to occur in Alaska, British Columbia and Arizona. It is represented in California by a few samples from the Sacramento-San Joaquin River delta (Hickson and Keeler-Wolf 2007) and the San Francisco Bay estuary.
Nations: CA?,US
States/Provinces: AZ?, BC?, CA, OR, WA
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.899167
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 5 Aquatic Vegetation Class | C05 | 5 |
| Subclass | 5.B Freshwater Aquatic Vegetation Subclass | S13 | 5.B |
| Formation | 5.B.2 Temperate to Polar Freshwater Aquatic Vegetation Formation | F057 | 5.B.2 |
| Division | 5.B.2.Na North American Freshwater Aquatic Vegetation Division | D049 | 5.B.2.Na |
| Macrogroup | 5.B.2.Na.2 Rocky Mountain Pond-lily - Pacific Mosquito Fern - Western Waterweed Western North American Freshwater Aquatic Vegetation Macrogroup | M109 | 5.B.2.Na.2 |
| Group | 5.B.2.Na.2.a Pond-lily species - Pondweed species - Duckweed species Freshwater Aquatic Vegetation Group | G544 | 5.B.2.Na.2.a |
| Alliance | A1741 Pacific Mosquito Fern - Mexican Mosquito Fern Aquatic Vegetation Alliance | A1741 | 5.B.2.Na.2.a |
| Association | CEGL003017 (Pacific Mosquito Fern, Mexican Mosquito Fern) Aquatic Vegetation | CEGL003017 | 5.B.2.Na.2.a |
Concept Lineage: equivalent to A.1741 (with edits)
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Azolla (filiculoides, mexicana) (Mosquito fern mats) Provisional Alliance (Sawyer et al. 2009) [52.106.00]
= Azolla (filiculoides, mexicana) Provisional Alliance (Mosquito fern mats) (Buck-Diaz et al. 2012)
= Azolla (filiculoides, mexicana) Provisional Herbaceous Alliance (CNPS 2017) [52.106.00]
>< Coastal and Valley Freshwater Marsh (#52410) (Holland 1986b)
>< Montane Freshwater Marsh (#52430) (Holland 1986b)
= Mosquito fern series (Sawyer and Keeler-Wolf 1995)
>< Transmontane Freshwater Marsh (#52420) (Holland 1986b)
= Azolla (filiculoides, mexicana) Provisional Alliance (Mosquito fern mats) (Buck-Diaz et al. 2012)
= Azolla (filiculoides, mexicana) Provisional Herbaceous Alliance (CNPS 2017) [52.106.00]
>< Coastal and Valley Freshwater Marsh (#52410) (Holland 1986b)
>< Montane Freshwater Marsh (#52430) (Holland 1986b)
= Mosquito fern series (Sawyer and Keeler-Wolf 1995)
>< Transmontane Freshwater Marsh (#52420) (Holland 1986b)
- Buck-Diaz, J., S. Batiuk, and J. M. Evens. 2012. Vegetation alliances and associations of the Great Valley ecoregion, California. California Native Society, Sacramento, CA. [http://cnps.org/cnps/vegetation/pdf/great_valley_eco-vegclass2012.pdf]
- CNPS [California Native Plant Society]. 2015-2017. A manual of California vegetation [online]. California Native Plant Society, Sacramento, CA. [http://vegetation.cnps.org/].
- Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
- Hickman, J. C. 1993. The Jepson manual: Higher plants of California. University of California Press, Ltd., Berkeley, CA. 1400 pp.
- Hickson, D., and T. Keeler-Wolf. 2007. Vegetation and land use classification and map of the Sacramento-San Joaquin River Delta. Prepared for the Bay Delta Region, California Department of Fish and Game by the Vegetation Classification and Mapping Program, California Department of Fish and Game, Sacramento. 152 pp. plus appendices.
- Holland, R. F. 1986b. Preliminary descriptions of the terrestrial natural communities of California. Unpublished report prepared for the California Department of Fish and Game, Nongame-Heritage Program and Natural Diversity Database, Sacramento. 156 pp.
- Mason, H. L. 1957. A flora of the marshes of California. University of California Press, Berkeley, CA.
- Sawyer, J. O., T. Keeler-Wolf, and J. Evens. 2009. A manual of California vegetation. Second edition. California Native Plant Society, Sacramento CA. 1300 pp.
- Sawyer, J. O., and T. Keeler-Wolf. 1995. A manual of California vegetation. California Native Plant Society, Sacramento. 471 pp.