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Kevin Doyle

Coast Sedge (Carex exilis)

Life history

Species overview

Coast Sedge (Carex exilis), a Wisconsin Threatened plant, is found in coastal Great Lakes bog and fen mats, where it can be locally abundant. Blooming occurs late May through early June; fruiting occurs early June through late July. The optimal identification period for this species is early June through late July.

Synonyms: None


  • Distinguishing characteristics: Densely cespitose; usually with a single terminal spike with widely spreading flattened perigynia with a strongly serrulate beak; leaves involute, 0.8 to 1.5 mm wide.
  • Flower characteristics: Solitary terminal spike (occasionally 1 to 3 smaller accessory spikes) gynecandrous with male portion 1 to 3 mm wide,up to 50-flowered and female portion 5 to 9.5 mm wide and up to 27-flowered, or plants sometimes unisexual with male and female spikes on different plants.
  • Fruit characteristics: Perigynia spreading to reflexed, castaneous to dark brown, 15-veined abaxially, faintly 7-veined adaxially, lanceolate-ovate to broadly ovate; beak serrulate, teeth blunt, soft; achenes ovate.
  • Leaf characteristics: 2 to 6 per culm; sheaths tight, inner band hyaline, apex concave, glabrous; blades involute, widest leaf 0.8-1.5 mm wide.


  • Blooming phenology: late May through early June
  • Fruiting phenology: early June through late July
  • Optimum time to identify: The optimal identification period for this species is early June through late July


  • Growth form: Graminoid
  • Vegetative reproduction:
  • Life cycle: Perennial
  • Section: Stellulatae
  • Comments: Associated Species: Carex michauxiana, C. livida, C. lasiocarpa, Arethusa bulbosa, Eleocharis robbinsii, Picea mariana, Larix laricina, Rhynchospora alba, R. fusca, Cladium mariscoides.

State status

Status and Natural Heritage Inventory documented occurrences in Wisconsin

The table below provides information about the protected status - state and federal - and the rank (S and G Ranks) for Coast Sedge (Carex exilis). See the Working List Key for more information about abbreviations. Counties shaded blue have documented occurrences for this species in the Wisconsin Natural Heritage Inventory database. The map is provided as a general reference of where this species has been found to date and is not meant as a range map.

Documented locations of Carex exilis in the Natural Heritage Inventory Database as of July 2015.

Summary Information
State StatusTHR
Federal Status in Wisconsinnone
State RankS1
Global RankG5
Tracked by NHIY

Habitats and landscapes

The Natural Heritage Inventory has developed scores indicating the degree to which each of Wisconsin's rare plant species is associated with a particular natural community or ecological landscape. This information is similar to that found in the Wildlife Action Plan for animals. As this is a work in progress, we welcome your suggestions and feedback.

General habitat information

  • Habitat description: Found in coastal Great Lakes bog and fen mats, where it can be locally abundant.
  • Soils: Moist soils.

Natural communities

This table lists the natural communities that are associated with Coast Sedge. Scores for natural community associations are: "significant" association (score=3), "moderate association" (score=2) or the species can be present but is only weakly associated with the community (score=1).

Natural communities score
Boreal Rich Fen 3
Great Lakes Shore Fen 3
Poor Fen 2

Ecological landscapes

This table lists the ecological landscape association scores for Coast Sedge. The scores (3=High, 2=Moderate, 1=Low, 0=None) also correspond to the map.

Map of the Ecological Landscapes of Wisconsin.

Species guidance

The Endangered Resources Program has developed avoidance measures and management guidelines for plants on the Natural Heritage Working List. These are a work in progress, and we welcome your suggestions and feedback. Sources used in developing this information can be found here.

Avoidance measures

These are specific actions designed to avoid "take" (mortality) of this species.

  • Avoid broadcast spraying of herbicides; use care with spot spraying.
  • Avoid known individual plant locations and conduct operations elsewhere when they are least likely to cause damage. Ideally, this would involve frozen, snow-covered ground. However, in areas of the state where frozen conditions are unreliable, very dry soils late in the growing season might be the best available alternative. Consult with a biologist, if needed.

Management guidance

Management guidelines are additional considerations that may help maintain or enhance habitat for this species

  • This species is likely sensitive to water quality. Following BMPs around streams and buffering associated drainages will reduce eutrophication and prevent water quality degradation.
  • Minimize disturbance to hydrology, including soil disturbance from rutting.
  • Survey for and control invasive plants prior to conducting timber operations, as these can be spread by vehicles and often respond vigorously to increased light; see forestry BMPs for invasive species.
  • Avoid rapid and dramatic reductions in canopy cover or basal area in wet areas to reduce risk of swamping.


Coast Sedge Photo.

Photo by Ryan O'Connor, Wisconsin DNR.

Coast Sedge Photo.

Photo by Kevin Doyle, Wisconsin DNR.

Coast Sedge Photo.

Photo by Kevin Doyle, Wisconsin DNR.

Coast Sedge Photo.

Photo by Eric Epstein, Wisconsin DNR.

Support for Wisconsin's rare plant information has been provided by the Division of Forestry, the Endangered Resources Fund and the Wisconsin Rare Plant Preservation Fund. To donate, visit the Natural Resources Foundation of Wisconsin [exit DNR].

Last revised: Wednesday, May 05, 2021
Southwest Savanna Southern Lake Michigan Coastal Western Coulees and Ridges Southeast Glacial Plains Central Sand Hills Central Lake Michigan Coastal Central Sand Plains Northern Lake Michigan Coastal Northern Lake Michigan Coastal Northeast Sands Western Prairie North Central Forest Northern Highlands Northwest Lowlands Northwest Sands Northwest Lowlands Superior Coastal Plains Forest Transition