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CEGL006833 Acorus calamus Tidal Marsh

Type Concept Sentence: No Data Available

Common (Translated Scientific) Name: European Sweetflag Tidal Marsh

Colloquial Name: Sweetflag Tidal Marsh

Hierarchy Level:  Association

Type Concept: This is an association of tidal freshwater marsh dominated by Acorus calamus that occurs in fresh to oligohaline reaches of tidal rivers along the Atlantic Coast from Massachusetts to Virginia. This association is best developed in higher, irregularly flooded elevations within freshwater tidal marshes but can occur in areas with a wide tidal range. Substrate is generally fine-particled, but varies from silts and silty mucks to peats and sands. The setting within the tidal marsh tends to be poorly drained; tidal flooding is ponded and of longer duration than adjacent areas. Acorus calamus is dominant, generally comprising at least 50% cover, over extensive patches within the interior of high marshes. Peltandra virginica is a frequent associate. Other associated species are variable and can include Bolboschoenus fluviatilis, Sagittaria latifolia, Polygonum punctatum, and Impatiens capensis. Species that can occasionally occur include Pontederia cordata, Zizania aquatica, Leersia oryzoides, Typha latifolia, Polygonum arifolium, Bidens coronata, Hibiscus moscheutos, and other Schoenoplectus spp. Murdannia keisak has been noted in the southern portion of the range. Acorus calamus is conspicuously dominant in spring and early summer. Later in the season, culms tend to lodge and form mats and be overtopped by other species.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This vegetation is considered a modified type by the Delaware Natural Heritage Program. Although the native status of Acorus calamus has been debated, North American specimens are apparently sterile triploids introduced from Europe (Coulling 2002).

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available

Floristics: This is a tall tidally flooded grassland dominated by Acorus calamus, which can form dense colonies over extensive patches within the interior of high marshes. Associated species are variable and can include Bolboschoenus fluviatilis (= Schoenoplectus fluviatilis), Peltandra virginica, Sagittaria latifolia, Polygonum punctatum, and Impatiens capensis. Species that can occasionally occur include Pontederia cordata, Zizania aquatica, Leersia oryzoides, Typha latifolia, Polygonum arifolium, Bidens coronata, Hibiscus moscheutos, and other Schoenoplectus spp. Murdannia keisak has been noted in the southern portion of the range Acorus calamus is conspicuously dominant in spring and early summer. Later in the season, culms tend to lodge and form mats and be overtopped by other species.

Dynamics:  Freshwater tidal marshes are naturally dynamic systems that are best developed where there is a major input of freshwater, a daily tidal range of at least 0.5 m, and a geomorphology that tends to constrict and magnify tidal influence in the upper reaches of the estuary (Odum et al. 1984). They are subject to diurnal flooding by tides and seasonal and episodic flooding from river discharge. Plant composition of freshwater tidal marshes generally occurs as a mosaic of patches dominated by a few or a single species. Species composition is determined by species life history characteristics, especially lifeform, phenology and mode of regeneration in response to microhabitat conditions and the frequency and duration of flooding. Plant composition has seasonal variation.

Acorus calamus forms large, clonal patches (Barrett 1989). Its rhizomes can locally raise the surface of the marsh, effectively ponding tidal waters and trapping debris and sediments in backmarsh areas (Caldwell 1990).
Environmental Description:  The association is best developed at higher, irregularly flooded elevations within fresh and oligohaline tidal marshes but can occur in areas with a wide tidal range. Substrate is generally fine-particled, but varies from silts and silty mucks to peats and sands. The setting within the tidal marsh tends to be poorly drained; tidal flooding is ponded and of longer duration than other areas. Acorus calamus can occur in low mid-tidal areas, but extensive colonies do not tend to develop in these situations.
Geographic Range: Currently described from Massachusetts to Virginia.

Nations: US

States/Provinces:  CT, DC?, DE, MA, MD, NJ, VA


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.Ne Atlantic & Gulf Coastal Marsh, Wet Meadow & Shrubland Division D322 2.C.4.Ne
Macrogroup 2.C.4.Ne.1 Annual Wild Rice - Saltmeadow Cordgrass - Pickerelweed Fresh-Oligohaline Tidal Marsh Macrogroup M066 2.C.4.Ne.1
Group 2.C.4.Ne.1.c <i>Zizania aquatica - Spartina patens - Amaranthus cannabinus</i> Freshwater Tidal Marsh Group G914 2.C.4.Ne.1.c
Alliance A4017 Green Arrow-arum - Pickerelweed - Arrowhead species Oligohaline Tidal Marsh Alliance A4017 2.C.4.Ne.1.c
Association CEGL006833 European Sweetflag Tidal Marsh CEGL006833 2.C.4.Ne.1.c
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: = Acorus calamus tidally-flooded grasslands (Metzler and Barrett 2006)
Concept Author(s): S.L. Neid

Author of Description: S.L. Neid and L.A. Sneddon

Acknowledgements: No Data Available

Version Date: 05-10-02
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  • Barrett, N. E. 1994. Vegetation patch dynamics in freshwater tidal wetlands. Ph.D. dissertation, University of Connecticut. 277 pp.
  • Caldwell, F. A. 1990. A floristic and vegetation analysis of a freshwater-tidal marsh on the Merrimack River, West Newbury, Massachusetts. Master''s thesis, University of New Hampshire. 96 pp.
  • Coulling, P. P. 2002. A preliminary classification of tidal marsh, shrub swamp, and hardwood swamp vegetation and assorted non-tidal, chiefly non-maritime, herbaceous wetland communities of the Virginia Coastal Plain. October 2002. Virginia Department of Conservation and Recreation, Division of Natural Heritage. Natural Heritage Technical Report 02-18. 30 pp.
  • Coxe, R. 2009. Guide to Delaware vegetation communities. Spring 2009 edition. State of Delaware, Division of Fish and Wildlife, Delaware Natural Heritage Program, Smyrna.
  • Eastern Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boston, MA.
  • Fleming, G. P., K. D. Patterson, and K. Taverna. 2017. The natural communities of Virginia: A classification of ecological community groups and community types. Third approximation. Version 3.0. Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond, VA. [http://www.dcr.virginia.gov/natural-heritage/natural-communities/]
  • Harrison, J. W. 2001. Herbaceous tidal wetland communities of Maryland''s eastern shore: Identification, assessment and monitoring. Report submitted to the U.S. EPA (Clean Water Act 1998 State Wetlands Protection Development Grant Program). Biodiversity Program, Maryland Department of Natural Resources, Wildlife and Heritage Division. 30 June 2001. [U.S. EPA Reference Wetland Natural communities of Maryland''s Herbaceous Tidal Wetlands Grant #CD993724].
  • Harrison, J. W. 2011. The natural communities of Maryland: 2011 working list of ecological community groups and community types. Unpublished report. Maryland Department of Natural Resources, Wildlife and Heritage Service, Natural Heritage Program, Annapolis. 33 pp.
  • Harrison, J. W., compiler. 2004. Classification of vegetation communities of Maryland: First iteration. A subset of the International Classification of Ecological Communities: Terrestrial Vegetation of the United States, NatureServe. Maryland Natural Heritage Program, Maryland Department of Natural Resources, Annapolis. 243 pp.
  • McCormick, J., and T. Ashbaugh. 1972. Vegetation of a section of Oldmans Creek Tidal Marsh and related areas in Salem and Gloucester counties, New Jersey. Bulletin of the New Jersey Academy of Science 17:31-37.
  • Metzler, K., and J. Barrett. 2006. The vegetation of Connecticut: A preliminary classification. State Geological and Natural History Survey, Report of Investigations No. 12. Connecticut Natural Diversity Database, Hartford, CT.
  • Odum, W. E., T. J. Smith, III, J. K. Hoover, and C. C. McIvor. 1984. The ecology of tidal freshwater marshes of the United States east coast: A community profile. FWS/OBS-83/17. USDI Fish & Wildlife Service, Office of Biological Services, Washington, DC. 176 pp.
  • Swain, P. C., and J. B. Kearsley. 2014. Classification of the natural communities of Massachusetts. Version 2.0. Natural Heritage & Endangered Species Program, Massachusetts Division of Fisheries and Wildlife. Westborough, MA. [http://www.mass.gov/nhesp/http://www.mass.gov/eea/agencies/dfg/dfw/natural-heritage/natural-communities/classification-of-natural-communities.html]