Myriophyllum spicatum - L.
Eurasian Water-milfoil
Other Common Names: Eurasian watermilfoil
Taxonomic Status: Accepted
Related ITIS Name(s): Myriophyllum spicatum L. (TSN 27039)
Unique Identifier: ELEMENT_GLOBAL.2.159460
Element Code: PDHAL040B0
Informal Taxonomy: Plants, Vascular - Flowering Plants - Water-Milfoil Family
 
Kingdom Phylum Class Order Family Genus
Plantae Anthophyta Dicotyledoneae Haloragales Haloragaceae Myriophyllum
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Concept Reference
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Concept Reference: Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Concept Reference Code: B94KAR01HQUS
Name Used in Concept Reference: Myriophyllum spicatum
Conservation Status
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NatureServe Status

Global Status: GNR
Global Status Last Changed: 22Mar1994
Rounded Global Status: GNR - Not Yet Ranked
Nation: United States
National Status: NNA
Nation: Canada
National Status: NNA (25Mar2016)

U.S. & Canada State/Province Status
United States Alabama (SNA), Alaska (SNA), Arkansas (SNA), California (SNA), Colorado (SNA), Connecticut (SNA), Delaware (SNA), Florida (SNA), Georgia (SNR), Indiana (SNA), Iowa (SNA), Kentucky (SNA), Louisiana (SNA), Maryland (SNA), Massachusetts (SNR), Michigan (SNA), Minnesota (SNA), Mississippi (SNA), Missouri (SNA), Nevada (SNA), New Hampshire (SNA), New Jersey (SNA), New York (SNA), North Carolina (SNA), Ohio (SNA), Oklahoma (SNA), Pennsylvania (SNA), South Carolina (SNA), Tennessee (SNA), Texas (SNA), Utah (SNA), Vermont (SNA), Virginia (SNA), Washington (SNA), West Virginia (SNA), Wisconsin (SNA)
Canada British Columbia (SNA), Manitoba (SNA), New Brunswick (SNA), Ontario (SNA), Prince Edward Island (SNA), Quebec (SNA)

Other Statuses

NatureServe Global Conservation Status Factors

Other NatureServe Conservation Status Information

Distribution
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U.S. States and Canadian Provinces
Color legend for Distribution Map
NOTE: The distribution shown may be incomplete, particularly for some rapidly spreading exotic species.

U.S. & Canada State/Province Distribution
United States AKexotic, ALexotic, ARexotic, CAexotic, COexotic, CTexotic, DEexotic, FLexotic, GA, IAexotic, INexotic, KYexotic, LAexotic, MA, MDexotic, MIexotic, MNexotic, MOexotic, MSexotic, NCexotic, NHexotic, NJexotic, NVexotic, NYexotic, OHexotic, OKexotic, PAexotic, SCexotic, TNexotic, TXexotic, UTexotic, VAexotic, VTexotic, WAexotic, WIexotic, WVexotic
Canada BCexotic, MBexotic, NBexotic, ONexotic, PEexotic, QCexotic

Range Map
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Ecology & Life History Not yet assessed
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Economic Attributes Not yet assessed
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Management Summary Not yet assessed
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Population/Occurrence Delineation Not yet assessed
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Population/Occurrence Viability
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U.S. Invasive Species Impact Rank (I-Rank)
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Disclaimer: While I-Rank information is available over NatureServe Explorer, NatureServe is not actively developing or maintaining these data. Species with I-RANKs do not represent a random sample of species exotic in the United States; available assessments may be biased toward those species with higher-than-average impact.

I-Rank: High
Rounded I-Rank: High
I-Rank Reasons Summary: Myriophyllum spicatum has invaded many natural lakes (Jacono and Richerson 2003), where it forms dense mats that alter dissolved oxygen levels (Jacono and Richerson 2003), reduces light penetration (Johnson and Blossey 2002), and negatively impacts macrophytes, macroinvertebrates, and fish abundance and diversity (Jacono and Richerson 2003). It has negative impacts on a native congener, Myriophyllum sibiricum, through both hybridization and competition. It is present in most of the continental US (Kartesz and Meacham 1999), and listed as noxious in 15 states (USDA-NRCS 2004). Recent reports indicate it is increasing within its range (Jacono and Richerson 2003). In addition to lake habitat, it infests ponds, and pools and stagnant to slowing moving fresh to slightly brackish water (Johnson and Blossey 2002). As only limited control is achieved through current management methods, biological control agents such as the milfoil beetle (Euhrychiopsis lecontei) are being explored (Johnson and Blossey 2002).
Subrank I - Ecological Impact: High
Subrank II - Current Distribution/Abundance: High
Subrank III - Trend in Distribution/Abundance: High
Subrank IV - Management Difficulty: High
I-Rank Review Date: 23Mar2006
Evaluator: Heffernan, K., rev. J. Cordiero and K. Gravuer
Native anywhere in the U.S?
Native Range: Eurasia (Randall 2004)

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Screening Questions

S-1. Established outside cultivation as a non-native? YES
Comments: Considered a major nusiance species in the Northeast, northern Midwest, and Pacific Northwest; also established in California, the Southwest and Southeast (Johnson and Blossey 2002; Couch and Nelson 1991; Jacono and Richerson 2003).

S-2. Present in conservation areas or other native species habitat? Yes
Comments: Native aquatic communities such as rivers and streams, brackish tidal creeks and bays (Johnson and Blossey 2002; Couch and Nelson 1991; Jacono and Richerson 2003).

Subrank I - Ecological Impact: High

1. Impact on Ecosystem Processes and System-wide Parameters:High significance
Comments: High densities reduce dissolved oxygen levels; reduces open-water habitat; reduced light penetration due to canopy formation (Johnson and Blossey 2002; Jacono and Richerson 2003).

2. Impact on Ecological Community Structure:High significance
Comments: Forms dense canopy and reduces light penetration (Johnson and Blossy 2002; Jacono and Richerson 2003). Myriophyllum sibiricum x spicatum hybrids also form dense, monospecific stands (Moody and Les, 2002).

3. Impact on Ecological Community Composition:High significance
Comments: Reduces macrophytes, macroinvertebrates, and fish abundance and diversity (Johnson and Blossy 2002; Jacono and Richerson 2003).

4. Impact on Individual Native Plant or Animal Species:High/Moderate significance
Comments: Competes with and hybridizes with the native Myriophyllum sibiricum (listed endangered in Pennsylvania). Hybrids with M. sibiricum occur in only a few localities in Wisconsin and Minnesota (Moody and Les, 2002; Roley and Newman, 2006) and possibly scattered in a few more in New England. Total proportion of M sibiricum threatened by M. spicatum unknown (Jacono and Richerson 2003).

5. Conservation Significance of the Communities and Native Species Threatened:High significance
Comments: Has invaded many natural lakes: 53 in Vermont, 160 in Indiana (Jacono and Richerson 2003).

Subrank II. Current Distribution and Abundance: High

6. Current Range Size in Nation:High significance
Comments: Present in all but ten continental states (Kartesz and Meacham 1999). Hybrids with M. sibiricum occur in only a few localities in Wisconsin and Minnesota (Moody and Les, 2002; Roley and Newman, 2006) and possibly scattered in a few more in New England.

7. Proportion of Current Range Where the Species is Negatively Impacting Biodiversity:High significance
Comments: Classified as a noxious weed in 15 states (USDA-NRCS 2004).

8. Proportion of Nation's Biogeographic Units Invaded:High significance
Comments: Over 30 TNC ecoregions invaded (USDA-NRCS 2004; Slaats 1999).

9. Diversity of Habitats or Ecological Systems Invaded in Nation:High significance
Comments: Deep to very shallow lakes, ponds, and pools; stagnant to slowing moving fresh to slightly brackish water (Johnson and Blossey 2002).

Subrank III. Trend in Distribution and Abundance: High

10. Current Trend in Total Range within Nation:High significance
Comments: Reported as recently expanding into many states (Jacono and Richerson 2003, Jordan 2005). In addition, it is surmised that the invasive hybridized Myriophyllum sibiricum x spicatum will likely continue to expand as Myriophyllum spicatum expands and parent plants cross with native Myriophyllum sibiricum.

11. Proportion of Potential Range Currently Occupied:Low significance
Comments: Already widespread (Jacono and Richerson 2003).

12. Long-distance Dispersal Potential within Nation:High significance
Comments: Still commerically available (Johnson and Blossey 2002; Jacono and Richerson 2003). Also, ditches along highway corridors have been shown to serve as migration corridors for invasive wetland plants (Wilcox, 1989).

13. Local Range Expansion or Change in Abundance:High significance
Comments: Abundance on the increase at many sites (Jacono and Richerson 2003). Recently reported spreading to new counties in New York and New England (Jordan 2005). In addition, it is surmised that the invasive hybridized Myriophyllum sibiricum x spicatum will likely continue to expand as Myriophyllum spicatum expands and parent plants cross with native Myriophyllum sibiricum.

14. Inherent Ability to Invade Conservation Areas and Other Native Species Habitats:High significance
Comments: Glacial lakes in Indiana, for example (Jacono and Richerson 2003). Invades new habitat (Couch and Nelson 1991)

15. Similar Habitats Invaded Elsewhere:Unknown
Comments: No data found.

16. Reproductive Characteristics:Moderate significance
Comments: Primarily by fragmentation; seed germination also reported (Johnson and Richerson 2002).

Subrank IV. General Management Difficulty: High

17. General Management Difficulty:High significance
Comments: Expensive mechanical and chemical methods (2,4 D) provide only limited control for as long as treatment continues. Biocontol agents are under development. (White et al. 1993; Johnson and Blossey 2002). One promising agent is the milfoil beetle, Euhrychiopsis lecontei, an aquatic herbivorous weevil whose native host is Myriophyllum sibiricum, but has developed a preference for Myriophyllum spicatum since its introduction into the U.S. It has been used as a successful management tool for M. spicatum, and similar declines in M. sibiricum have not been observed except when it occurs in areas without M. spicatum (Tamayo and Grue, 2004; Roley and Newman, 2006). The milfoil beetle has also been found to be a successful management tool for controlling hybrid Myriophyllum sibiricum x spicatum. Resistance to weevil herbivory was found to be greatest for Myriophyllum sibiricum, intermediate for Myriophyllum sibiricum x spicatum and least for Myriophyllum spicatum (Roley and Newman, 2006).

18. Minimum Time Commitment:High/Moderate significance
Comments: Herbicide control requires continued treatement (White et al. 1993; Johnson and Blossey 2002).

19. Impacts of Management on Native Species:High significance
Comments: May result in fish kills and increased algal growth (White et al. 1993; Johnson and Blossey 2002).

20. Accessibility of Invaded Areas:Insignificant
Comments: Not mentioned as a concern in referenced literature (Johnson and Blossey 2002).
Authors/Contributors
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Botanical data developed by NatureServe and its network of natural heritage programs (see Local Programs), The North Carolina Botanical Garden, and other contributors and cooperators (see Sources).

References
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  • Borrowman, K.R., E.P.S. Sager and R.A. Thum. 2014. Distribution of biotypes and hybrids of Myriophyllum spicatum and associated Euhrychiopsis lecontei in lakes of Central Ontario, Canada. Lake and Reservoir Management 39(1): 94-104.


  • Aiken, S.G. 1981. A Conspectus of Myriophyllum (Haloragaceae) in North America. Brittonia 33 (1): 57-69. A81AIK01PAUS.

  • Aiken, S.G., P.R. Newroth, and I. Wile. 1979. The biology of Canadian weeds. 34. Myriophyllum spicatum L. Canadian Journal of Plant Science 59: 2Ol-215.

  • Couch, R. and E. Nelson. 1991. The exotic Myriophyllums of North America. Proceedings from enhancing the states' lake management programs - monitoring and lake impact assessment. 5-11.

  • Crow, G.E. and C.B. Hellquist. 2000. Aquatic and Wetland Plants of Northeastern North America. A Revised and Enlarged Edition of Norman C. Fassett's A Manual of Aquatic Plants. Vol. 1, Pteridophytes, Gymnosperms, and Angiosperms: Dicotyledons. University of Wisconsin Press, Madison, Wisconsin. 448 pp.

  • Ellstrand, N.C. and K.A. Schierenbeck. 2000. Hybridization as a stimulus for the evolution of invasiveness in plants? Proceedings of the National Academy of Sciences, 97(13): 7043-7050.

  • Jacono, C.C. and M.M. Richerson. 2003. Myriophyllum spicatum. United States Geological Survey, Biological Resources Division, Center for Aquatic Resources Studies. Available at http://nas.er.usgs.gov/plants/docs/my_spica.html

  • Johnson, D.A., Jr., I. Bosch, and M.D. Valentino. 2001. Mapping and quantifying stands of Eurasian watermilfoil in Conesus Lake, New York. SUNY Gyneseo Journal of Science and Mathematics, 2(1): 1-6.

  • Johnson, R.L. and B. Blossey. 2002. Eurasian watermilfoil. In: Van Driesche, R., et al., 2002. Biological Control of Invasive Plants in the Eastern United States, USDA Forest Service Pulication FHTET-2002-04. 413 p.

  • Johnson, R.L., and B. Blossey. 2002. Eurasian Watermilfoil. In R. Van Driesche, S. Lyon, B. Blossey, M. Hoddle, and R. Reardon (tech. coords.), Biological Control of Invasive Plants in the Eastern United States. Publication FHTET-2002-04. U.S. Department of Agriculture, Forest Service. Available online at: http://www.invasive.org/eastern/biocontrol/6EurasianMilfoil.html.

  • Jordan, M. 2005. Weed spread on Long Island, NY (New York, USA). Posting to TNC Invasive Species Listserve: Digest #142 (October 2005). Online. Available: http://tncweeds.ucdavis.edu/listserv.html (Accessed 2005).

  • Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.

  • Kartesz, J.T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: Kartesz, J.T., and C.A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, N.C.

  • Maine Center for Invasive Aquatic Plants. 2004. Virtual Herbarium Fact Sheets. http://www.mciap.org/herbarium/index.php. Maine Center for Invasive Aquatic Plants, Auburn, Maine (accessed March 2006).

  • Moody, M.L. and D.H. Les. 2002. Evidence of hybridity in invasive watermilfoil (Myriophyllum) populations. Proceedings of the National Academy of Science, 99(23): 14867-14871.

  • Moody, M.L., and D.H. Les. 2007. Geographic distribution and genotypic composition of invasive hybrid watermilfoil (Myriophyllum spicatum · M. sibiricum) populations in North America. Biological Invasions 9: 559?570.

  • Randall, R. 2004. Global Compendium of Weeds. Department of Agriculture of Western Australia. Available at http://www.hear.org/gcw/index.html (accessed February 2004).

  • Roley, S.S. and R.M. Newman. 2006. Developmental performance of the milfoil weevil, Euhrychiopsis lecontei (Coleoptera: Curculionidae), in northern watermilfoil, Eurasian watermilfoil, and hybrid (northern x Eurasian) watermilfoil. Environmental Entomology, 35(1): 121-126.

  • Schweitzer, J.A., G.D. Martinsen, and T.G. Whitham. 2002. Cottonwood hybrids gain fitness traits of both parents: a mechanism for their long-term persistence? American Journal of Botany, 89: 981-990.

  • Slaats, J. 1999. TNC ecoregions and divisions map. Available at http://gis.tnc.org/data/MapbookWebsite/map_page.php?map_id=9 (accessed February 2004).

  • Tamayo, M. and C.E. Grue. 2004. Developmental performance of the milfoil weevil (Coleoptera: Curculionidae) on watermilfoils in Washington State. Population Ecology, 33(4): 872-880.

  • The Nature Conservancy. 2001. Map: TNC Ecoregions of the United States. Modification of Bailey Ecoregions. Online . Accessed May 2003.

  • USDA, NRCS. 2004. The PLANTS Database, Version 3.5 (http://plants.usda.gov) . National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

  • White, D.J., E. Haber, and C. Keddy. 1993. Invasive plants of natural habitats in Canada. Canadian Museum of Nature. Ottawa, Canada. 121 pp. Available: http://www.cws-scf.ec.gc.ca/publications/inv/index_e.cfm.

  • Wilcox, D.A. 1989. Migration and control of purple loosestrife (Lythrum salicaria L.) along highway corridors. Environmental Management, 13: 365-370.

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