Print Report

CEGL007081 Bacopa monnieri - Eleocharis spp. Thin Floating Marsh

Type Concept Sentence: No Data Available


Common (Translated Scientific) Name: Herb-of-Grace - Spikerush species Thin Floating Marsh

Colloquial Name: Herb-of-Grace Thin Floating Marsh

Hierarchy Level:  Association

Type Concept: This is a thin floating mat of aquatic and wetland plants described from Jean Lafitte National Historical Park and Preserve, Louisiana. It is a type of mixed, native marsh that forms in areas that have been disturbed by extensive herbivory, air boat activity, or other intense disturbance. It is often expressed as a matrix of taller plants such as Kosteletzkya virginica and Ludwigia leptocarpa intermingled with shorter ones such as Bidens laevis, Polygonum hydropiperoides, and Thelypteris palustris. Interspersed within this taller matrix are patches of thinner floating mats characterized by Bacopa monnieri, Eleocharis olivacea, and Hydrocotyle spp. The Eleocharis forms a low, dense continuous mat, and the other marsh plants are lying on it or rising above it. Other species that may be present include Andropogon glomeratus, Cyperus spp., Lythrum lineare, Morella cerifera, Sacciolepis striata, Sagittaria lancifolia, Spartina patens, Symphyotrichum subulatum, Typha domingensis, Vigna luteola and the non-native Panicum repens. This vegetation has been observed to form extensive areas within other more uniform marsh types (e.g., dominated by Panicum hemitomon, Sagittaria lancifolia, Spartina patens, Typha domingensis, etc.). These patches are thought to result from herbivory by nutria, muskrats, deer, etc., as well as subsidence. It is found within the larger marsh matrix and on the margins of lakes and large natural bayous, rather than in heavily-traveled waterways.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Nolfo-Clements (2006) identified a thin-mat community at Jean Lafitte National Historical Park and Preserve dominated or codominated by Eleocharis olivacea, Eleocharis radicans, and Eleocharis vivipara. Associated species included Hydrocotyle spp., Bacopa monnieri, Ludwigia repens, and occasionally Micranthemum umbrosum, Sagittaria latifolia, Pontederia cordata, Cyperus spp., Habenaria repens, Fuirena pumila, Juncus filipendulus, Ludwigia grandiflora, Alternanthera philoxeroides, Phyla lanceolata, Polygonum punctatum, and Schoenoplectus americanus. Occasional floating aquatic species include Salvinia minima, Lemna minor, Spirodela polyrrhiza, and Wolffiella gladiata. Her community appears to be compatible with this association (CEGL007081). More information is needed to better separate the fresh to oligohaline marshes along the coast of Louisiana into associations.

Similar NVC Types: No Data Available
note: No Data Available

Physiognomy and Structure: No Data Available

Floristics: This vegetation is often expressed as a matrix of taller plants such as Kosteletzkya virginica and Ludwigia leptocarpa intermingled with shorter ones such as Bidens laevis, Polygonum hydropiperoides (= Persicaria hydropiperoides), and Thelypteris palustris. Interspersed within this taller matrix are patches of thinner floating mats characterized by Bacopa monnieri, Eleocharis olivacea, and Hydrocotyle spp. The Eleocharis forms a low, dense continuous mat, and the other marsh plants are lying on it or rising above it. Other species that may be present include Andropogon glomeratus, Cyperus spp., Lythrum lineare, Morella cerifera, Sacciolepis striata, Sagittaria lancifolia, Spartina patens, Symphyotrichum subulatum, Typha domingensis, Vigna luteola and the non-native Panicum repens.

Dynamics:  No Data Available

Environmental Description:  This freshwater herbaceous marsh vegetation is located adjacent to estuarine and riverine tidal waters (NPS 2005), and has been observed to form in disturbed areas impacted by intense air boat activity or herbivory by nutria, muskrats, deer, etc., as well as in subsiding marshes on the margins of lakes and large natural bayous, rather than in heavily-traveled waterways. It may form extensive patches within other more uniform marsh types (e.g., dominated by Panicum hemitomon, Sagittaria lancifolia, Spartina patens, Typha domingensis, etc.).

Geographic Range: Described from Jean Lafitte National Park, Louisiana, and probably found across the still fresh to oligohaline waters of the outer Gulf Coastal Plain.

Nations: US

States/Provinces:  LA




Confidence Level: Low - Poorly Documented

Confidence Level Comments: No Data Available

Grank: GNR

Greasons: No Data Available


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): M. Pyne

Author of Description: M. Pyne

Acknowledgements: No Data Available

Version Date: 10-21-15

  • NPS [National Park Service]. 2005. Jean Lafitte NHP 2005 Habitat Data Map (1:12,000) created by USGS-NWRC. Unpublished data shared by NPS.
  • Nolfo-Clements, L. E. 2006. Vegetative survey of wetland habitats at Jean Lafitte National Historical Park and Preserve in southeastern Louisiana. Southeastern Naturalist 5(3):499-514.
  • Sasser, C. E., J. G. Gosselink, E. M. Swenson, M. Swarzenski, and N. C. Leibowitz. 1996. Vegetation, substrate and hydrology in floating marshes in the Mississippi River delta plain wetlands, USA. Vegetatio 122:129-142.
  • Southeastern Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Durham, NC.