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A1881 Polygonum spp. Shoreline Wet Meadow Alliance

Type Concept Sentence: This alliance covers various southeastern and mid-Atlantic wet depressions, lakes, and ponds dominated by various Polygonum species (section Persicaria), singly or in combination, or with other obligate wetland plant species. Associations have been described that are dominated by, or contain, Polygonum amphibium, Polygonum glabrum, Polygonum hydropiperoides, Polygonum lapathifolium, Polygonum pensylvanicum, Polygonum punctatum, and/or related Polygonum spp. The many associated species vary with geography and habitat.

Common (Translated Scientific) Name: Knotweed species Shoreline Wet Meadow Alliance

Colloquial Name: Eastern Knotweed Shoreline Wet Meadow

Hierarchy Level:  Alliance

Type Concept: This alliance covers various southeastern and Mid-Atlantic wet depressions, lakes, and ponds dominated by various Polygonum species (section Persicaria), singly or in combination, or with other obligate wetland plant species. Associations have been described that are dominated by, or contain, Polygonum amphibium, Polygonum glabrum, Polygonum hydropiperoides, Polygonum lapathifolium, Polygonum pensylvanicum, Polygonum punctatum, and/or related Polygonum spp. The many associated species vary with geography and habitat. In western Kentucky, this alliance occurs in marshes associated with the Ohio River in backflood areas around oxbows, beaver-flooded areas, levees, and depressional drainages. Associated species include Nelumbo lutea, Cephalanthus occidentalis, Sagittaria brevirostra, Peltandra virginica, and Juncus effusus. Associates in Oklahoma include Ammannia coccinea, Helianthus annuus, Lemna minor, Stuckenia pectinata, Spirodela polyrrhiza, Utricularia gibba, and Xanthium strumarium. In Mississippi, one example of this vegetation is dominated by the perennial Polygonum glabrum; associated species include Lemna minor, Saccharum giganteum, Hydrocotyle umbellata, Saururus cernuus, Carex lupulina, Triadenum walteri, Cephalanthus occidentalis, Leersia sp., Ludwigia peploides, Boehmeria cylindrica, Juncus effusus, Rhynchospora corniculata, Ludwigia decurrens, Habenaria repens, Mikania scandens, Scirpus cyperinus, and others. It occurs as a band ringing the shores of ponds in the East Gulf Coastal Plain and along the banks of ditches and sloughs in the Mississippi River Alluvial Plain. This alliance also occurs in a wide variety of human- and beaver-created wetlands. Composition is highly variable and re-evaluation may be required as additional data become available. In the western United States and adjacent Canada, this alliance is found primarily over a wide elevational range from near sea level to over 2700 m. Stands are found in permanently flooded depressions such as margins of lake shores and oxbow lakes in river floodplains. The vegetation is characterized by the dominance or codominance of Polygonum amphibium. Associates may include species of Potamogeton and other aquatic plants.

Diagnostic Characteristics: Wetland basins or shores of lakes or ponds where wave action is minimal.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: The alliance as described is currently limited to the southeastern U.S., but its occurrence in the northeastern states is known but not well-documented.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This vegetation is generally dominated by forbs.

Floristics: Stands of this alliance are dominated by various Polygonum species (section Persicaria), singly or in combination, or with other obligate wetland plant species. Associations have been described that are dominated by, or contain, Polygonum amphibium, Polygonum glabrum (= Polygonum densiflorum), Polygonum hydropiperoides, Polygonum lapathifolium, Polygonum pensylvanicum, Polygonum punctatum, and/or related Polygonum spp. The many associated species vary with geography and habitat. In western Kentucky, associated species include Nelumbo lutea, Cephalanthus occidentalis, Sagittaria brevirostra, Peltandra virginica, and Juncus effusus. Associates in Oklahoma include Ammannia coccinea, Helianthus annuus, Lemna minor, Stuckenia pectinata (= Potamogeton pectinatus), Spirodela polyrrhiza, Utricularia gibba (= Utricularia biflora), and Xanthium strumarium. In Mississippi, one example of this vegetation is dominated by the perennial Polygonum glabrum; associated species include Lemna minor, Saccharum giganteum, Hydrocotyle umbellata, Saururus cernuus, Carex lupulina, Triadenum walteri, Cephalanthus occidentalis, Leersia sp., Ludwigia peploides, Boehmeria cylindrica, Juncus effusus, Rhynchospora corniculata, Ludwigia decurrens, Habenaria repens, Mikania scandens, Scirpus cyperinus, and others. In the western United States and adjacent Canada, stands are characterized by the dominance or codominance of Polygonum amphibium. Associates may include species of Potamogeton and other aquatic plants. Floating-leaved aquatic forbs cover at least 30% of the water''s surface (Kunze 1994).

Dynamics:  No Data Available
Environmental Description:  In the southeastern United States, this alliance occurs in a wide variety of human- and beaver-created wetlands (wet depressions, lakes, and ponds), including a band ringing the shores of ponds in the East Gulf Coastal Plain and in ditches and sloughs in the Mississippi River Alluvial Plain.
Geographic Range: This alliance is widespread but scattered throughout the eastern United States.

Nations: CA,US

States/Provinces:  AL, FL?, GA, KY, LA, MS, NC, NJ, OK, PA, SC, TN, TX?


Confidence Level: Low

Confidence Level Comments: No Data Available
Grank: GNR

Greasons: No Data Available
Type Name Database Code Classification Code
Class 2 Shrub & Herb Vegetation Class C02 2
Subclass 2.C Shrub & Herb Wetland Subclass S44 2.C
Formation 2.C.4 Temperate to Polar Freshwater Marsh, Wet Meadow & Shrubland Formation F013 2.C.4
Division 2.C.4.Nd Eastern North American Temperate Freshwater Marsh, Wet Meadow & Shrubland Division D323 2.C.4.Nd
Macrogroup 2.C.4.Nd.3 Eastern North American Wet Shoreline Vegetation Macrogroup M880 2.C.4.Nd.3
Group 2.C.4.Nd.3.b Eastern North American Wet Shoreline Vegetation Group G756 2.C.4.Nd.3.b
Alliance A1881 Knotweed species Shoreline Wet Meadow Alliance A1881 2.C.4.Nd.3.b
Association CEGL002430 Smartweed species - Mixed Forbs Shoreline Wet Meadow CEGL002430 2.C.4.Nd.3.b
Association CEGL004249 Dotted Smartweed - Smooth Beggarticks Shoreline Wet Meadow CEGL004249 2.C.4.Nd.3.b
Association CEGL004290 (Swamp Smartweed, Dotted Smartweed) - Cutgrass species Shoreline Wet Meadow CEGL004290 2.C.4.Nd.3.b
Association CEGL004699 Water Knotweed - (Swamp Smartweed) Shoreline Wet Meadow CEGL004699 2.C.4.Nd.3.b
Association CEGL004966 Dense-flower Knotweed - (Sugarcane Plumegrass) Shoreline Wet Meadow CEGL004966 2.C.4.Nd.3.b
Association CEGL005458 Water Knotweed - Broadleaf Arrowhead Riverine Wet Meadow CEGL005458 2.C.4.Nd.3.b
Association CEGL008555 Smartweed species - Savanna Panicgrass Shoreline Wet Meadow CEGL008555 2.C.4.Nd.3.b
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: >< Polygonum amphibium herbaceous series (Hoagland 1997)
>< Polygonum pensylvanicum herbaceous series (Hoagland 1997)
? Polygonum spp. (section Persicaria) herbaceous alliance (Hoagland 1998a)
Concept Author(s): B.W. Hoagland (1997)

Author of Description: L.A. Sneddon

Acknowledgements: No Data Available

Version Date: 12-18-14
  • 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.
  • Faber-Langendoen, D., and Midwest State Natural Heritage Program Ecologists. 1996. Terrestrial vegetation of the midwest United States. International classification of ecological communities: Terrestrial vegetation of the United States. The Nature Conservancy, Arlington, VA.
  • Hoagland, B. W. 1997. Preliminary plant community classification for Oklahoma. Unpublished draft document, version 35629. University of Oklahoma, Oklahoma Natural Heritage Inventory, Norman. 47 pp.
  • Hoagland, B. W. 1998a. Classification of Oklahoma vegetation types. Working draft. University of Oklahoma, Oklahoma Natural Heritage Inventory, Norman. 43 pp.
  • Kunze, L. M. 1994. Preliminary classification of native, low elevation, freshwater wetland vegetation in western Washington. Washington State Department of Natural Resources, Natural Heritage Program. 120 pp.