Description
Myriophyllum aquaticum has the growth form of a 'creeping emergent' plant, growing partly submerged in shallow water (Rejmankova 1992).
Myriophyllum sibiricum (Shortspike Watermilfoil, Northern Watermilfoil) is native; M. spicatum (Eurasian Watermilfoil) is introduced.
Taxonomy
| Kingdom | Phylum | Class | Order | Family | Genus |
|---|---|---|---|---|---|
| Plantae | Magnoliophyta | Magnoliopsida | Haloragales | Haloragaceae | Myriophyllum |
Synonyms
Invasion History
Chesapeake Bay Status
| First Record | Population | Range | Introduction | Residency | Source Region | Native Region | Vectors |
|---|---|---|---|---|---|---|---|
| 1919 | Established | Unknown | Introduced | Regular Resident | South America | South America | Ornamental(Aquatic Plant) |
History of Spread
Myriophyllum aquaticum (Parrots-Feather), a native of South America, was first recorded in 1890 in the Washington D.C. area as an ornamental planting next to a government building, which was photgraphed in 1890 , and in Haddonville, NJ, in Harris millpond (Delaware River drainage) (Nelson and Couch 1985; Couch and Nelson 1991). It was probably imported as an ornamental fishpond plant by aquarium dealers or government agencies. Isolated records in widely separated areas before 1920 (DE, NJ, MO, CA, TX, LA, FL), suggesting many separate escapes. By 1940, records of M. aquaticum stretch from NY to FL and KS to TX, with isolated Western records (Couch and Nelson 1991; Nelson and Couch 1985). Many populations in northern areas seem to have been ephemeral (Fernald 1950), but by 1961-1980, it was well established in southeast states (VA-TX; OK) (Couch and Nelson 1991; Nelson and Couch 1985), and in the San Francisco Bay Delta (Cohen and Carlton 1995). It has been introduced to Australia, New Zealand, Indonesia, Japan, and Africa (Sutton 1985).
The first wild record of M. aquaticum in Chesapeake Bay is a record from Hunting Creek, Alexandria VA (Hitchcock and Standley 1919). It was reported as an ocasional pond escape in DE (Tatnall 1946) and coastal VA (Wass 1972). There is a record from tidal waters of the Bush River (Harford County MD) in 1951 (US National Herbarium collections). Addtional tidal records Wass (1972) are from the Chickahominy River and a record as 'common' (Simmons et al. 1995) in the Potomac River, in King George County VA, where the major rivers (Rappahannock and Potomac) are tidal. It was reported from five tidewater VA counties in Harvill et al. (1986) and seven in Harvill et al. (1992), so its range may be expanding. Gene Silberhorne (1995) and Donna Ware (1996) had not noticed the plant during fieldwork in VA, which may indicate that it is rare and local.
History References - Cohen and Carlton 1995; Couch and Nelson 1991; Fernald 1950; Harvill et al. 1986; Harvill et al. 1992; Simmons et al. 1995; Sutton 1985; Tatnall 1946; US National Herbarium collections.
Invasion Comments
Ecology
Environmental Tolerances
| For Survival | For Reproduction | |||
|---|---|---|---|---|
| Minimum | Maximum | Minimum | Maximum | |
| Temperature (ºC) | ||||
| Salinity (‰) | 0.0 | 10.0 | 0.0 | 5.0 |
| Oxygen | ||||
| pH | ||||
| Salinity Range | fresh-oligo |
Age and Growth
| Male | Female | |
|---|---|---|
| Minimum Adult Size (mm) | ||
| Typical Adult Size (mm) | 2000.0 | |
| Maximum Adult Size (mm) | ||
| Maximum Longevity (yrs) | ||
| Typical Longevity (yrs |
Reproduction
| Start | Peak | End | |
|---|---|---|---|
| Reproductive Season | |||
| Typical Number of Young Per Reproductive Event |
|||
| Sexuality Mode(s) | |||
| Mode(s) of Asexual Reproduction |
|||
| Fertilization Type(s) | |||
| More than One Reproduction Event per Year |
|||
| Reproductive Startegy | |||
| Egg/Seed Form |
Impacts
Economic Impacts in Chesapeake Bay
Myriophyllum aquaticum (Parrot's Feather) is widely planted and grown in the Chesapeake Bay watershed, but 'wild' populations appear to be uncommon and scattered.
Aesthetic - Myriophyllum aquaticum is grown as an ornamental in aquariums and fishponds (Couch and Nelson 1991), and is raised commercially in 'water-garden' nurseries in Frederick County MD, based on a Web search (Fofonoff, personal observation). While this plant is considered beautiful for its delicate leaves, excessively dense growth is unattractive. Dense growths can cause swimming and boating problems, odors due to decay of washed up plants, etc. (Sutton 1985). However, their appears to be no indication of problems in the Chesapeake Bay region where it seems to be very local.
Referencess - Couch and Nelson 1991; Sutton 1985
Economic Impacts Outside of Chesapeake Bay
Myriophyllum aquaticum (Parrot's Feather) has caused problems with stream flow, irrigation, and navigation in shallow water in the southeast United States, Japan, South Africa, and CA (Weldon et al. 1965; Sutton 1985). However, it is generally less invasive than M. spicatum (Couch and Nelson 1991) and has been considered 'more beneficial than noxious' (Sutton 1985). 'In some countries, it is eaten as a vegetable' (Sutton 1985).
References - Couch and Nelson 1991; Sutton 1985; Weldon et al. 1965
Ecological Impacts on Chesapeake Native Species
Myriophyllum aquaticum (Parrot's Feather) is usually not a seriously invasive weed (Couch and Nelson 1991) and is apparently quite local in Chesapeake watershed (Brown and Brown 1984; Harvill et al. 1992) and in tidal waters. Impacts reported elsewhere include:
Competition- Myriophyllum aquaticum, while localized in the watershed, has been listed as invasive in DE, MD, and VA (Cooley 1993; Delaware Natural Heritage Program 1998; Virginia Department of Conservation and Recreation 1999).
Habitat Change - Myriophyllum aquatiicum can provide cover and shelter for aquatic organisms (Sutton 1985).
Food - It is eaten by herbivorous organisms, including a flea -beetle (Lysathia ludoviciana) native to the southern United States (Sutton 1985).
References - Cooley 1993; Couch and Nelson 1991; Delaware Natural Heritage Program 1998; Harvill et al. 1992; Sutton 1985; Virginia Department of Conservation and Recreation 1999
Ecological Impacts on Other Chesapeake Non-Native Species
Myriophyllum aquaticum (Parrot's Feather) is usually not a seriously invasive weed (Couch and Nelson 1991) and is apparently quite local in Chesapeake watershed (Harvill et al. 1992). Impacts reported elsewhere include:
Competition- Myriophyllum aquaticum is a potential competitor with Ludwigia peploides (Creeping Water-Primrose) and Alternanthera philoxeroides (Alligatorweed) which have a similar 'creeping emergent' growth form (Rejmankova 1991). However, M. aquaticum appears to be uncommon and local around Chesapeake Bay.
References- Couch and Nelson 1991; Fofonoff personal observation; Rejmankova 1991; Harvill et al. 1992
References
Brown, Melvin L.; Brown, Russell G. (1984) Herbaceous Plants of Maryland, , College Park. Pp.Carter, Virginia; Gammon, Patricia T.; Bartow, Nancy C. (1984) Submersed aquatic plants of the tidal Potomac River, Geological Survey Bulletin 1543: 1-58
Cohen, Andrew N.; Carlton, James T. (1995) Nonindigenous aquatic species in a United States estuary: a case study of the biological invasions of the San Francisco Bay and Delta, , Washington DC, Silver Spring MD.. Pp.
Cooley, Gene (1993) Invasive exotic plants that threaten native species and natural habitats in Maryland., , Annapolis MD. Pp.
Couch, Richard; Nelson, Edward (1985) Myriophyllum spicatum in North America, In: (Eds.) First International Symposium on Watermilfoil (Myriophyllum spicatum) and Related Haloragaceae Species. , Vicksburg, Missisippi. Pp. 8-18
Couch, Richard; Nelson, Edward (1991) The exotic Myriophyllums of North America, In: (Eds.) A National Conference on Enhancing the States' Lake Management Programs. , Chicago, Illinois. Pp. 5-11
1998 Non-native plant species in Delaware. http://www.dnrec.statede.us/iw/weeds.htm
Fernald, Merritt L. (1950) Gray's Manual of Botany, In: (Eds.) . , New York. Pp.
Haller, William T.; Sutton, D. L; Barlowe, W. C. (1974) Effects of salinity on the growth of several aquatic macrophytes, Ecology 55: 891-894
Harvill, A. M., Jr.; Bradley, T. R.; Stevens, C. E.; Weiboldt, T.F.; Ware, D.E.; Ogle, D. W. (1986) Atlas of the Virginia Flora, , Farmville, VA. Pp.
Harvill, A. M.; Bradley, Ted R.; Stevens, Charles E.; Wieboldt, Thomas F.; Ware, Donna M. E.; Ogle, Douglas W.; Ramsey, Gwynn W.; Fleming, Gary P. (1992) Atlas of the Virginia Flora, , Burkeville, VA. Pp.
Hitchcock, A. S.; Standley, P. C. (1919) Flora of the District of Columbia and Vicinity., In: (Eds.) . , Washington, D. C.. Pp.
Hotchkiss, Neil (1967) Underwater and floating-leaved plants of the United States and Canada, Bureau of Sport Fisheries and Wildlife, Resource Publication 44: 1-124
Hurley, Linda M. (1990) Field guide to the submersed aquatic vegetation of Chesapeake Bay., , Annapolis, MD. Pp.
Kartesz, John T. (1994) A synonymized checklist of the vascular flora of the United States, Canada, and Greenland., In: (Eds.) . , Portland OR. Pp.
Muenscher, Walter C. (1944) Aquatic plants of the United States., In: (Eds.) . , Ithaca NY. Pp.
1997-2024 USDA PLANTS Database.. Onine databse
Nelson, Edward M.; Couch, Richard W. (1985) History of the introduction and distribution of Myriophyllum aquaticum in North America., In: (Eds.) Proceedings of the First International Symposium on Watermilfoil (Myriophyllum spicatum) and related Haloragaceae species.. , Vicksburg, MS. Pp. 19-26
Rejmankova, Eliska (1992) Ecology of creeping macrophytes with special reference to Ludwigia peploides (H. B. K.) Raven, Aquatic Botany 43: 283-299
Silberhorne, Eugene (December 1995) Introduced plants in the Chesapeake Bay region, telephone conversation;, , Gloucester Point VA. Pp.
Simmons, Mark P.; Ware, Donna M.; Hayden, W. John (1995) The vascular flora of the Potomac River watershed of King George County, Virginia, Castanea 60: 179-209
Sutton, David L. (1985) Proceedings of First International Symposium on Watermilfoil (Myriophyllum spicatum), In: (Eds.) . , Vancouver, BC. Pp. 59-71
Tatnall, Robert R. (1946) Flora of Delaware and the Eastern Shore, , Wilmington. Pp.
1999 Invasive Alien Plant Species of Virginia. http://www.state.va.us/~dcr/dnh/invlist.htm
Ware, Donna (January 1996) Introduced plants in the Chesapeake Bay region, telephone conversation, , Williamsburg VA. Pp.
Wass, Melvin L. (1972) A checklist of the biota of lower Chesapeake Bay, Special Scientific Report, Virginia Institute of Marine Science 65: 1-290
Weldon, L. W.; Blackburn, R. D.; Harrison, D. S. (1969) Common aquatic weeds., , Washington, D.C.. Pp.