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G661 South Atlantic & Gulf Coastal Beach Group

Type Concept Sentence: This vegetation type combines sparse beach vegetation of the outer coastal zone dominated by various combinations of Cakile species and Ipomoea species, as well as by Atriplex patula, Sesuvium portulacastrum, and Suaeda linearis, in irregularly flooded beaches and salt flats from Delaware to Texas and adjacent Mexico.

Common (Translated Scientific) Name: South Atlantic & Gulf Coastal Beach Group

Colloquial Name: South Atlantic & Gulf Coastal Beach

Hierarchy Level:  Group

Type Concept: This vegetation type accommodates sparse beach vegetation of the outer coastal zone dominated by various combinations of Cakile species (Cakile constricta, Cakile edentula ssp. harperi, Cakile geniculata) and Ipomoea species (Ipomoea pes-caprae, Ipomoea imperati). Other typical species include Atriplex patula, Canavalia rosea, Chamaesyce mesembrianthemifolia, Iva imbricata, Portulaca spp., Sesuvium portulacastrum, Suaeda linearis, and others. This vegetation occurs along the Atlantic and portions of the northern Gulf of Mexico coasts, from Delaware to Texas and adjacent Mexico. It includes annual-dominated sand flats on island end flats and upper ocean beaches, within the reach of storm tides and extreme lunar tides, as well as irregularly flooded beaches and salt flats.

Diagnostic Characteristics: This sparse beach vegetation of the outer coastal zone from North Carolina to Texas is dominated by various combinations of Cakile and Ipomoea species as well as by Atriplex patula, Sesuvium portulacastrum, and Suaeda linearis in irregularly flooded beaches and salt flats.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Split between North Atlantic versus South Atlantic is based on the Acadian vs. Virginian marine zones, which meets in central Virginia (L. Sneddon pers. comm. 2012). For more information on diagnostic criteria for the range limits of this group, see information in ~Uniola paniculata - Panicum amarum Dune Grassland Alliance (A1199)$$.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This group consists of sparse beach, sand flat, and salt flat vegetation from the outer coastal zone of the southeastern United States and adjacent Mexico. The physiognomy of the Atriplex-dominated phases tends to be of scattered mound-like clumps of vegetation (mostly Sesuvium portulacastrum) in a wet sand flat.

Floristics: Examples of this vegetation are dominated by various combinations of Cakile species (Cakile constricta, Cakile edentula ssp. harperi, Cakile geniculata) and Ipomoea species (Ipomoea pes-caprae, Ipomoea imperati, Ipomoea sagittata). Other typical species include Atriplex patula, Canavalia rosea, Chamaesyce mesembrianthemifolia, Iva imbricata, Portulaca spp., Sesuvium maritimum, Sesuvium portulacastrum, Suaeda linearis, Vigna luteola, and others. Several taxa are succulents. In the South Atlantic coastal zone, other characteristic species include mostly annual herbs, such as the rare Amaranthus pumilus, Chamaesyce bombensis, Chamaesyce polygonifolia, and Salsola kali ssp. kali (exotic). Grasses may be present, including Panicum amarum, Spartina patens, and Sporobolus virginicus. The composition and structure of some southern examples show transition towards some tropical beach vegetation.

Dynamics:  This vegetation is affected and maintained by storm tides and extreme lunar tides.
Environmental Description:  This vegetation includes annual-dominated sand flats on island end flats and upper ocean beaches, within the reach of storm tides and extreme lunar tides. The South Atlantic Coast phase of this vegetation occupies the upper portion of ocean beaches in the southern part (Cape Hatteras, North Carolina, to Cape Romain, South Carolina) of the microtidal region (barrier islands with coastal geomorphology dominated by hurricane overwash rather than tidal energy). The Atriplex-dominated phases of this vegetation are found on the backside of the ends of barrier islands, where examples are only irregularly flooded. In contrast to Salicornia- or Distichlis-dominated areas, they apparently accumulate less salt. The physiognomy tends to be of scattered mound-like clumps of vegetation (mostly Sesuvium portulacastrum) in a wet sand flat.
Geographic Range: This vegetation occurs along the Atlantic and portions of the northern Gulf of Mexico coasts, from Delaware to Texas and adjacent Mexico.

Nations: MX,US

States/Provinces:  AL, DE, FL, GA, LA, MD, MS, MXTAM, NC, SC, TX, VA


Confidence Level: Moderate

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.B Temperate & Boreal Grassland & Shrubland Subclass S18 2.B
Formation 2.B.4 Temperate to Polar Scrub & Herb Coastal Vegetation Formation F005 2.B.4
Division 2.B.4.Na Eastern North American Coastal Scrub & Herb Vegetation Division D026 2.B.4.Na
Macrogroup 2.B.4.Na.1 Eastern North American Coastal Beach & Rocky Shore Macrogroup M060 2.B.4.Na.1
Group 2.B.4.Na.1.a South Atlantic & Gulf Coastal Beach Group G661 2.B.4.Na.1.a
Alliance A1868 Shoreline Sea-purslane - Spear Saltbush - Annual Seepweed Salt Flat Alliance A1868 2.B.4.Na.1.a
Alliance A3683 Searocket species - Morning-glory species Sparse Beach Alliance A3683 2.B.4.Na.1.a
Concept Lineage: G124 split into G660 & G661 (DFL 7-24-12)

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: No Data Available
Concept Author(s): D. Faber-Langendoen and M. Pyne, in Faber-Langendoen et al. (2015)

Author of Description: M. Pyne

Acknowledgements: We have incorporated significant descriptive information developed and compiled by J.B. Nelson, M.P. Schafale, and A.S. Weakley.

Version Date: 05-05-15
  • 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]
  • Nelson, J. B. 1986. The natural communities of South Carolina: Initial classification and description. South Carolina Wildlife and Marine Resources Department, Division of Wildlife and Freshwater Fisheries, Columbia, SC. 55 pp.
  • Schafale, M. P., and A. S. Weakley. 1990. Classification of the natural communities of North Carolina. Third approximation. North Carolina Department of Environment, Health, and Natural Resources, Division of Parks and Recreation, Natural Heritage Program, Raleigh. 325 pp.
  • Wieland, R. G. 1994a. Marine and estuarine habitat types and associated ecological communities of the Mississippi Coast. Museum Technical Report 25. Mississippi Department of Wildlife, Fisheries, and Parks, Museum of Natural Science, Jackson, MS. 270 pp.