Print Report
A1745 Hydrilla verticillata - Myriophyllum spicatum Ruderal Aquatic Vegetation Alliance
Type Concept Sentence: This ruderal aquatic vegetation occurs in freshwater wetlands of lakes, rivers, and pond, and is commonly dominated by the exotics Egeria densa, Hydrilla verticillata, Hygrophila polysperma, Limnophila sessiliflora, Myriophyllum aquaticum, Myriophyllum spicatum, Najas minor, and Potamogeton crispus, which can spread vigorously and form extensive subsurface mats.
Common (Translated Scientific) Name: Water-thyme - Eurasian Water-milfoil Ruderal Aquatic Vegetation Alliance
Colloquial Name: Ruderal Water-thyme - Eurasian Water-milfoil Aquatic Vegetation
Hierarchy Level: Alliance
Type Concept: This ruderal aquatic vegetation occurs in freshwater wetlands of lakes, rivers, and ponds, in areas which are permanently or semipermanently flooded. The dominant growth form is submersed aquatic plants. The most common species include the exotics Egeria densa, Hydrilla verticillata, Myriophyllum aquaticum, Myriophyllum spicatum, Najas minor, and Potamogeton crispus. These exotic species can spread vigorously and form extensive growth in submersed areas of the water, often reaching the surface.
Diagnostic Characteristics: Floating aquatic vegetation dominated by ruderal submersed plant species such as Egeria densa, Hydrilla verticillata, Hygrophila polysperma, Limnophila sessiliflora, Myriophyllum aquaticum, Myriophyllum spicatum, Najas minor, and Potamogeton crispus. Native rooted floating-leaved and submergent species have little cover, generally less than 10-20%.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This alliance has only one poorly documented association in it.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Submersed herbaceous aquatic plants dominate. They can have sparse to dense cover.
Floristics: The invasive exotic aquatic plants which are dominant include Egeria densa, Hydrilla verticillata, Hygrophila polysperma, Limnophila sessiliflora, Myriophyllum aquaticum, Myriophyllum heterophyllum, Myriophyllum spicatum, Najas minor, and Potamogeton crispus.
Dynamics: Hydrilla verticillata is an invasive alien species. Since its introduction, it has rapidly spread across the southeastern United States, its spread into man-made lakes being exacerbated by the transport of propagules on boat propellers. It produces vegetative propagules known as turions, which can resist desiccation for long periods of time. Because these plants grow submersed in water, they get some protection from very cold air temperatures during winter months. After flooding events, these plants can establish in new areas where the floodwater has carried them. Many of these plants can also be spread to new areas on the props of boats. Various control methods have been used to reduce nuisance infestations (Gettys et al. 2009).
Environmental Description: Climate: This aquatic vegetation occurs in both warm-temperate areas, which have a humid climate, and in cool-temperate regions. Soil/substrate/hydrology: This aquatic vegetation occurs in freshwater wetlands that are permanently or semipermanently flooded. Areas may be impounded, natural lakes, or low-gradient flowing streams and rivers. Often patches of this vegetation will occur in the more slowly flowing sections of rivers and streams.
Geographic Range: This alliance is found in eastern Canada, eastern, midwestern and southeastern United States, Texas, and eastern Mexico.
Nations: CA,MX,US
States/Provinces: AL, CT, DE, FL, GA, IA, IL, IN, KS, KY, LA, MA, ME, MI, MN, MO, MS, NC, ND, NE, NH, NJ, NY, OH, OK, ON, PA, QC, SC, TN, TX, VA, VT, WI, WV
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.899168
Confidence Level: Low
Confidence Level Comments: No Data Available
Grank: GNA
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.90 Common Water-hyacinth - Brazilian Waterweed - Alligator-weed Ruderal Aquatic Vegetation Macrogroup | M401 | 5.B.2.Na.90 |
| Group | 5.B.2.Na.90.a Common Water-hyacinth - Alligator-weed - Water Chestnut Ruderal Freshwater Aquatic Vegetation Group | G595 | 5.B.2.Na.90.a |
| Alliance | A1745 Water-thyme - Eurasian Water-milfoil Ruderal Aquatic Vegetation Alliance | A1745 | 5.B.2.Na.90.a |
| Association | CEGL004702 Water-thyme Ruderal Aquatic Vegetation | CEGL004702 | 5.B.2.Na.90.a |
Concept Lineage: This alliance equals old A.1745.
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: No Data Available
- ANS Task Force. 2010. The Lake Champlain Basin aquatic invasive species guide. Lake Champlain Basin Program. [http://adkinvasives.com/wp-content/uploads/2014/01/Lake-Champlain-Basin-Aquatic-Invasive-Species-Guide.pdf]
- Aquatic Nuisance Species Program. 2003. Illegal aquatic plants of South Carolina. South Carolina Department of Natural Resources, West Columbia, SC. [http://www.dnr.sc.gov/water/envaff/aquatic/img/illegalaqua.pdf]
- Cowardin, L. M., V. Carter, F. C. Golet, and E. T. LaRoe. 1979. Classification of wetlands and deepwater habitats of the United States. FWS/OBS-79/31. USDI Fish & Wildlife Service, Office of Biological Services, Washington, DC. 103 pp.
- 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.
- Gettys, L. A., W. T. Haller, and M. Bellaud, editors. 2009. Biology and control of aquatic plants: A best management practices handbook. Aquatic Ecosystem Restoration Foundation, Marietta GA. 210 pp. [http://plants.ifas.ufl.edu/misc/pdfs/AERF_handbook.pdf]
- Lui, K., M. Butler, M. Allen, J. da Silva, and B. Brownson. 2008. Field guide to aquatic invasive species: Identification, collection and reporting of aquatic invasive species in Ontario waters. Queen''s Printer for Ontario. MNR # 52089. [http://www.ontariostewardship.org/councils/duff-simcoe/files/invading_species_field_guide.pdf]