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G525 Eleocharis obtusa - Eragrostis hypnoides - Ludwigia palustris Temperate Pacific Freshwater Wet Mudflat Group

Type Concept Sentence: These herbaceous freshwater mudflats are found scattered throughout the western U.S. and Canada, occurring primarily on seasonally or tidally flooded shallow lakebeds and floodplains. They range from sparsely vegetated to thick mats and are may be dominated by Crassula aquatica, Eleocharis obtusa, Eragrostis hypnoides, Gnaphalium palustre, Lilaeopsis occidentalis, Limosella aquatica, and/or Ludwigia palustris.

Common (Translated Scientific) Name: Blunt Spikerush - Teal Lovegrass - Marsh Seedbox Temperate Pacific Freshwater Wet Mudflat Group

Colloquial Name: Temperate Pacific Freshwater Wet Mudflat

Hierarchy Level:  Group

Type Concept: This group consists of communities that occur on freshwater mudflats found scattered throughout the temperate regions of the western U.S. and Canada. They are dominated mainly by low-statured annual plants and range in physiognomy from sparsely vegetated mud to extensive sods of herbaceous vegetation. The predominant species include Crassula aquatica, Eleocharis obtusa, Eragrostis hypnoides, Gnaphalium palustre, Lilaeopsis occidentalis, Limosella aquatica, and/or Ludwigia palustris. In the Pacific Northwest, they occur primarily in seasonally or tidally flooded shallow lakebeds and on floodplains, especially along the lower Columbia River. During any one year, they may be absent because of year-to-year variation in river water levels. Mudflats must be exposed before the vegetation develops from the seedbank.

Diagnostic Characteristics: Extensive tidally or seasonally drained shallow lakebeds or floodplains exposing mudflats that may develop low-statured herbaceous annual vegetation.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: No Data Available

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Low-statured annual plants from sparsely vegetated mud to extensive sods of herbaceous vegetation.

Floristics: The predominant species include Crassula aquatica, Cyperus squarrosus, Eleocharis obtusa, Eragrostis hypnoides, Gnaphalium palustre, Lilaeopsis occidentalis, Limosella aquatica, Ludwigia palustris, and Rorippa curvisiliqua.

Dynamics:  Stands may be absent because of year-to-year variation in river water levels. Mudflat vegetation develops from the seedbank only after water has receded and the mudflat is exposed to air.
Environmental Description:  Climate: Temperate. Soil/substrate/hydrology: Seasonally flooded shallow lakebeds and on floodplains.
Geographic Range: This group is found throughout the temperate regions of the western U.S. and Canada, from Alaska south into California, east into Idaho, Montana, Wyoming, Utah, Nevada and Colorado. It is best known and described from along the Columbia River, but occurs in similar habitats throughout the temperate west.

Nations: CA,US

States/Provinces:  AK, BC, CA, CO, ID, MT, NV, OR, UT, WA, WY


Confidence Level: High

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.Nb Western North American Temperate Freshwater Marsh, Wet Meadow & Shrubland Division D031 2.C.4.Nb
Macrogroup 2.C.4.Nb.4 Vancouverian Lowland Marsh, Wet Meadow & Shrubland Macrogroup M073 2.C.4.Nb.4
Group 2.C.4.Nb.4.a Blunt Spikerush - Teal Lovegrass - Marsh Seedbox Temperate Pacific Freshwater Wet Mudflat Group G525 2.C.4.Nb.4.a
Alliance A3850 Nodding Beggarticks - Western Goldentop - Marsh Seedbox Intertidal Mudflat Alliance A3850 2.C.4.Nb.4.a
Alliance A3851 Blunt Spikerush - Teal Lovegrass Intertidal Mudflat Alliance A3851 2.C.4.Nb.4.a
Alliance A3901 Western Grasswort Freshwater Tidal Mudflat Alliance A3901 2.C.4.Nb.4.a
Alliance A4179 Oregon Gumweed - Gumweed species Wet Mudflat Alliance A4179 2.C.4.Nb.4.a
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: No Data Available
Concept Author(s): C. Chappell, in Faber-Langendoen et al. (2011)

Author of Description: C. Chappell and G. Kittel

Acknowledgements: No Data Available

Version Date: 12-02-15
  • Chappell, C., and J. Christy. 2004. Willamette Valley-Puget Trough-Georgia Basin Ecoregion Terrestrial Ecological System EO Specs and EO Rank Specs. Appendix 11 in: J. Floberg, M. Goering, G. Wilhere, C. MacDonald, C. Chappell, C. Rumsey, Z. Ferdana, A. Holt, P. Skidmore, T. Horsman, E. Alverson, C. Tanner, M. Bryer, P. Lachetti, A. Harcombe, B. McDonald, T. Cook, M. Summers, and D. Rolph. Willamette Valley-Puget Trough-Georgia Basin Ecoregional Assessment, Volume One: Report prepared by The Nature Conservancy with support from The Nature Conservancy of Canada, Washington Department of Fish and Wildlife, Washington Department of Natural Resources (Natural Heritage and Nearshore Habitat programs), Oregon State Natural Heritage Information Center and the British Columbia Conservation Data Centre.
  • Christy, J. A. 2004. Native freshwater wetland plant associations of northwestern Oregon. Oregon Natural Heritage Information Center, Oregon State University, Portland, OR.
  • Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
  • Holland, V. L., and D. J. Keil. 1995. California vegetation. Kendall/Hunt Publishing Company, Dubuque, IA. 516 pp.
  • Rodriguez, D., K. G. Sikes, T. Keeler-Wolf, G. Kittel, J. Curtis, C. Curley, and J. Evens. 2017. Vegetation classification of Channel Islands National Park. Report to the National Park Service, Fort Collins, CO.