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Many-headed Sedge (Carex sychnocephala)

Life history

Species overview

Many-headed Sedge (Carex sychnocephala), a Wisconsin Special Concern plant, is found on muddy, sandy, marly, and peaty shorelines of lakes and ponds. Blooming occurs early July through early September; fruiting occurs late July through late October. The optimal identification period for this species is late July through late September.

Synonyms: None


  • Distinguishing characteristics: Densely cespitose; leaf-like bracts 2 to 3.5 mm wide, much longer than the spikelet; perigynia appressed and very narrowly lanceolate, less than 1 mm broad.
  • Flower characteristics: 3 to 8 spikes, densely clustered except, often, the proximal 1 to 2, obovoid-oblanceoloid, base acute to acuminate, apex truncate; terminal and lateral spikes pistillate; subtended by leaf-like bracts 2 to 3.5 mm wide, much longer than the spikelet.
  • Fruit characteristics: Perigynia appressed, green or gold to light brown, conspicuously veined abaxially, 0 to 9 veined adaxially, very narrowly lanceolate, less than 1 mm wide; beak tip white, green, or gold, narrowly flat, ciliate-serrulate; achenes elliptic to ovate.
  • Leaf characteristics: 0 to 3 blades per culm; sheaths white-hyaline adaxially, summit U-shaped, smooth.


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


  • Growth form: Graminoid
  • Vegetative reproduction: Weakly rhizomatous, though often lacks conspicuous rhizomes and has a small diffuse root system, making it appear annual
  • Life cycle: Perennial
  • Section: Cyperoideae
  • Comments: Associated Species: Bidens cernua, Potentilla anserina, Juncus balticus, Eupatorium perfoliatum, Leersia oryzoides, Euthamia graminifolia.

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 Many-headed Sedge (Carex sychnocephala). 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 sychnocephala in the Natural Heritage Inventory Database as of July 2015.

Summary Information
State StatusSC
Federal Status in Wisconsinnone
State RankS2
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 on muddy, sandy, marly, and peaty shorelines of lakes and ponds.
  • Soils: Wet, sandy, peaty, calcareous soils.

Natural communities

This table lists the natural communities that are associated with Many-headed 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).

Ecological landscapes

This table lists the ecological landscape association scores for Many-headed 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 wet areas such as the bottom of wooded kettles in forests where this species has been reported.
  • Avoid direct disturbance to sensitive microsites such as seeps, cliffs, and moss-covered boulders.
  • 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

  • Buffer management around unique microhabitats such as ephemeral ponds, seeps, etc.
  • Minimize disturbance to hydrology, including soil disturbance from rutting.
  • Avoid disturbance to shorelines and the forest-beach interface.
  • 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.


Many-headed Sedge Photo.

Photo by Ryan O'Connor, Wisconsin DNR.

Many-headed Sedge Photo.

The edge of a sandy beach is suitable habitat for many-headed sedge.

Photo by  staff, Wisconsin DNR.

Many-headed Sedge Photo.

Photo by  staff, Wisconsin DNR.

Many-headed Sedge Photo.

Photo © Emmet Judziewicz.

Many-headed Sedge Photo.

Photo © Emmet Judziewicz.

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