Description
Potentially Misidentified Species - Polygonum hydropiperoides (Swamp Smartweed) and P. punctatum (Dotted Smartweed) are native.
Synonymy - Pursh (1814) confused P. hydropiper with P. hydropiperoides, referring to P. hydropiper as 'P. hydropiperoides', and P. hydropiperoides as 'P. mite' . This confusion was made by other botanists (e.g. Aikin 1837; Brereton 1830), until corrected by Gray (Gray 1848).
Taxonomy
| Kingdom | Phylum | Class | Order | Family | Genus |
|---|---|---|---|---|---|
| Plantae | Magnoliophyta | Magnoliopsida | Polygonales | Polygonaceae | Polygonum |
Synonyms
Invasion History
Chesapeake Bay Status
| First Record | Population | Range | Introduction | Residency | Source Region | Native Region | Vectors |
|---|---|---|---|---|---|---|---|
| 1830 | Established | Stable | Cryptogenic | Regular Resident | Europe | Eurasia | Shipping(Dry Ballast), Agriculture(Agricultural Weed) |
History of Spread
Polygonum hydropiper (Water Pepper) is native to Eurasia and Africa, but its invasion status in North America is uncertain (Timson 1966). It has been considered native to both North America and Europe (Brown and Brown 1984; Agricultural Research Service 1971; Harvill et al. 1992), introduced in part (e.g. 'Introduced southeastward, indigenous northward and westward' Fernald and Robinson 1908; 'Either native or adventive throughout our range' Fernald 1950), or wholly introduced (Gleason 1963; Gleason and Cronquist 1991; Mills et al. 1997). Pursh (1814) found P. hydropiper (as P. hydropiperoides, see 'Taxonomy') 'in inundated and exsiccated places, common, Canada to Carolina'. Gray (1848) described P. hydropiper as 'well-known'. It is now found from Quebec to British Columbia, AL to CA (Gleason and Cronquist 1991).
Polygonum hydropiper is not on a list of ~ 500 species represented by herbarium specimens collected in MD or in VA floras before 1753 (Brown et al. 1987; Reveal 1983). Pursh (1814), who gave P. hydropiper's range as 'Canada to Carolina', collected in VA in 1806 (Harvill et al. 1992, so he may have found the species in the Chesapeake region. Records of 'P. hydropiperoides' in Washington D.C. (Brereton 1831) and Baltimore (Aikin 1837) are assumed to refer to P. hydropiper (Gray 1848) since 'P. mite', a synonym of P. hydropiperoides (Gray 1848) was also reported (see 'Taxonomy'). P. hydropiper is identified as such in successive Washington D.C. (Potomac-Side Naturalist's Club 1876; Ward 1881; Hitchcock and Standley 1919) and Baltimore floras (Sollers 1888). It is generally listed for 'damp soils' (Brown and Brown 1984; Fernald 1950), but there are not many specific records for tidal marshes. Shreve et al. (1910) listed it as 'common' on the MD coastal Plain; Brown and Brown (1984) as 'infrequent'. Harvill et al. (1992) show records from 15 of ~30 tidewater VA counties and many interior counties.
It was reported for tidal fresh marshes in the Elk and Northeast Rivers and 'transitional (fresh-brackish) marshes, on the western shore of MD (Shreve et al. 1910), and for a marsh (presumably tidal) in St. Marys County MD (Krauss et al. 1971). Simmons et al. (1995) found it in an 'upper tidal marsh' in King George County VA. (Whigham 1995) considers it locally abundant in tidal marshes in the Upper Bay region.
History References - Agricultural Research Service 1971; Aikin 1837; Brereton 1830; Brown and Brown 1984; Brown et al. 1987; Fernald 1950; Gleason 1963; Gleason and Cronquist 1991; Gray 1848; Harvill et al. 1992; Hitchcock and Standley 1919; Krauss et al. 1971; Mills et al. 1997; Potomac-Side Naturalists' Club 1876; Pursh 1814; Robinson and Fernald 1908; Shreve et al. 1910; Simmons et al. 1995; Sollers 1888; Timson 1966; Ward 1881
Invasion Comments
Ecology
Environmental Tolerances
| For Survival | For Reproduction | |||
|---|---|---|---|---|
| Minimum | Maximum | Minimum | Maximum | |
| Temperature (ºC) | ||||
| Salinity (‰) | 0.0 | 0.0 | ||
| Oxygen | ||||
| pH | 5.8000000000 | 7.6500000000 | ||
| Salinity Range | fresh-oligo |
Age and Growth
| Male | Female | |
|---|---|---|
| Minimum Adult Size (mm) | 100.0 | 100.0 |
| Typical Adult Size (mm) | 450.0 | 450.0 |
| Maximum Adult Size (mm) | 900.0 | 900.0 |
| Maximum Longevity (yrs) | ||
| Typical Longevity (yrs | 0.5 | 0.5 |
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
Polygonum hydropiper (Water Pepper) probably only has only minor impacts in Chesapeake Bay proper, but like other Polygonum spp., its seeds may be an important waterfowl food ( Perry 1981). In the watershed, P. hydropiper may be an occasionally troublesome weed in damp soil (Muenscher 1982).
References- Muenscher 1982; Perry 1981
Economic Impacts Outside of Chesapeake Bay
Polygonum hydropiper (Water Pepper) is occasionally a troublesome weed in damp pastures and fields (Agricultural Research Service 1971; Muenscher 1982). Its seeds may be an important waterfowl food (Perry 1981).
References- Agricultural Research Service 1971; Muenscher 1982; Perry 1981
Ecological Impacts on Chesapeake Native Species
Impacts of Polygonum hydropiper (Water Pepper) on native biota in Chesapeake Bay wetlands have not been reported.
Competition - Competition with other wetland plants seems possible but not documented. In general, P. hydropiper appears to be less abundant or widespread than Polygonum punctatum (Dotted Smartweed), P. hydropiperoides (Swamp Smartweed), and others in tidal wetlands. One description, primarily for the British Isles is: 'Not of high competitive ability, preferring rather open habitats or closed pure stands (Timson 1966).
Food/Prey - Polygonum spp. seeds are an important waterfowl food (Perry 1981). 'Adult plants are usually immune from grazing by animals, rabbit nibbling, etc. because of the acrid taste of the leaves' (Timson 1966).
Toxic- The plant's sap has an intensely acrid flavor (Gray 1848), and causes eye irritation and contains insect anti-feeding compounds (Muenscher 1982).
References - Gray 1848; Muenscher 1982; Timson 1966; Perry 1981
Ecological Impacts on Other Chesapeake Non-Native Species
Polygonum hydropiper (Water Pepper) is a possible competitor with P. lapathifolium (Dock-Leaved Smartweed) and P. cespitosum (Asian Ladies-Thumb), but this is not documented.
References
Agricultural Research Service (1971) Common weeds of the United States., In: (Eds.) . , Washington, D.C.. Pp.Aikin, W. E. A. (1837) Catalogue of phenogamous plants and ferns, native or naturalized, growing in the vicinity of Baltimore, Maryland., Transactions of the Maryland Academy of Sciences and Literature 1: 55-91
Brereton, J. A. (1830) Prodromus of the Flora Columbiana, , Washington, D.C.. Pp.
Brown, Melvin L.; Brown, Russell G. (1984) Herbaceous Plants of Maryland, , College Park. Pp.
Brown, Melvin L.; Reveal, J. L; Broome, C. R.; Frick, George F. (1987) Comments on the vegetation of colonial Maryland, Huntia 7: 247-283
Gleason, Henry A. (1963) The new Britton and Brown illustrated flora of the northeastern United States and adjacent Canada, In: (Eds.) . , New York. Pp.
Gleason, Henry A.; Cronquist, Arthur (1991) Manual of vascular plants of northeastern United States and adjacent Canada, In: (Eds.) . , Bronx, New York. Pp.
Gray, Asa (1848) A manual of botany of the northern United States., In: (Eds.) . , Boston. Pp.
Grime. J. P.; Hodgson, J. G.; Hunt, R. (1988) Comparative plant ecology: A functional approach to common British species, , London. 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
Kartesz, John T. (1994) A synonymized checklist of the vascular flora of the United States, Canada, and Greenland., In: (Eds.) . , Portland OR. Pp.
Krauss, R.W.; Brown, R. G.; Rappleye, R. D.; Owens, A. B.; Shearer, C.; Hsiao, E.; Reveal, J. (1971) Checklist of plant species occurring within the hightide limits of the Chesapeake Bay, and its tributaries., , College Park, Maryland. Pp.
Mills, Edward L.; Scheuerell, Mark D.; Carlton, James T.; Strayer, David (1997) Biological invasions in the Hudson River: an inventory and historical analysis., New York State Museum Circular 57: 1-51
Muenscher, Walter C. (1980) Weeds., In: (Eds.) . , Ithaca, NY. Pp.
Perry, Matthew C. (1981) Asiatic Clam (Corbicula manilensis) and other foods used by waterfowl in the James River, Virginia, Estuaries 4: 229-233
Pursh, Frederick (1814) Flora Americae Septentrionalis or, a Systematic Arrangement and Description of the Plants of North America, , Hirschburg. Pp.
Resource Management Inc. (1993) National list of plant species that occur in wetlands., , Minneapolis.. Pp.
Robinson, Benjamin Lincoln; Fernald, Merrit L. (1908) Gray's New Manual of Botany., , New York. Pp.
Shreve, Forrest M.; Chrysler, M. A.; Blodgett, Frederck H.; Besley, F. W. (1910) The Plant Life of Maryland, , Baltmore. 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
Sollers, Basil (1888) Check list of plants compiled for the vicinity of Baltimore., , Baltimore. Pp.
Timson, J. (1966) Polygonum hydropiper L., Journal of Ecology 54: 815-821
Ward, L. F. (1881) Guide to the flora of Washington and Vicinity, United States National Museum Bulletin 22: 1-264
1995 Conversation with Paul Fofonoff, Introduced plants in Chesapeake Bay..