Share your observations

Share your observations of plants or non-game animals with the Natural Heritage Inventory

Rare animals
Find rare and non-game animals.
Rare plants
Learn about plants on the Natural Heritage Working List.
Rare lichens
Discover Wisconsin's lichens.
Natural communities
Explore Wisconsin's natural communities.
Other features
Discover unique resources.
Rare plant monitoring annual report

Catch up with the latest news in rare plant monitoring efforts throughout Wisconsin.

Eagle license plate

Help care for rare plants and animals by ordering an Endangered Resources plate.

Contact information
For information on Wisconsin's rare plants, contact:
Kevin Doyle

Clustered Sedge (Carex cumulata)

Life history

Species overview

Clustered Sedge (Carex cumulata), a Wisconsin Special Concern plant, is found in disturbed areas of barrens near Glacial Lake Wisconsin, including borrow pits, roadsides, sphagnum boggy woods, and wooded sandstone bluff tops. Blooming occurs throughout June; fruiting occurs early July through early September. The optimal identification period for this species is early July through late August.

Synonyms: Carex straminea var. cumulata


  • Distinguishing characteristics: Densely cespitose; pistillate scales much shorter than perigynia. Sometimes occurs with C. merritt-fernaldii, distinguished by its adaxially green-veined sheaths, obovate perigynia and usually broader (3 to 5 mm) leaves.
  • Flower characteristics: 5 to 9 sessile spikes, each 7 to 10 mm long, aggregated into such a dense cluster that spikelets are nearly at right angles to the rachis; staminate portion 2 mm or less.
  • Fruit characteristics: Perigynia flattened, appressed, greenish to dark brown, conspicuously 3 to 7-veined abaxially, inconspicuously veined adaxially, obovate, broadest at about the middle, concavo-convex; achenes lenticular, elliptic.
  • Leaf characteristics: 2 to 4 blades per fertile culm; 3 to 5 mm wide with sheaths adaxially green-veined nearly to collar, with a white-hyaline band or sharp Y-shaped hyaline region at collar; basal sheaths somewhat fibrous, adaxially firm, summits truncate, prolonged 0.3 mm beyond collar, abaxially finely papillose; distal ligules 2 to 7 mm.


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


  • Growth form: Graminoid
  • Vegetative reproduction: Rhizomatous
  • Life cycle: Perennial
  • Section: Ovales
  • Comments: Associated Species: Pinus banksiana, Quercus ellipsoidalis, Polygala cruciata, Euthamia graminifolia, Spiraea tomentosa, Euphorbia corollata.

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 Clustered Sedge (Carex cumulata). 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 cumulata in the Natural Heritage Inventory Database as of July 2015.

Summary Information
State StatusSC
Federal Status in Wisconsinnone
State RankS2
Global RankG4G5
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 disturbed areas of barrens near Glacial Lake Wisconsin, including borrow pits, roadsides, sphagnum boggy woods, and wooded sandstone bluff tops.
  • Soils: Dry, rocky or sandy soils.

Natural communities

This table lists the natural communities that are associated with Clustered 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 Clustered Sedge. The scores (3=High, 2=Moderate, 1=Low, 0=None) also correspond to the map.

Map of the Ecological Landscapes of Wisconsin.

Ecological landscape score
Central Sand Plains 3

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 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.
  • Avoid broadcast spraying of herbicides; use care with spot spraying.

Management guidance

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

  • Prescribed burns and/or brushing may be beneficial (dependent on local site conditions).
  • Maintain and restore open habitat through selective clearing and brushing.
  • 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.


Clustered Sedge Photo.

Photo © Andrew Hipp, Wisconsin State Herbarium

Clustered Sedge Photo.

Photo © John Scholze.

Clustered Sedge Photo.

Carex cumulata is often found in open sandy soil such as along ATV trails.

Photo © John Scholze.

Clustered Sedge Photo.

The perigynia of Carex cumulata are widest above the middle.

Photo by Kevin Doyle, Wisconsin DNR.

Clustered Sedge Photo.

The spikelets of Carex cumulata are usually tightly bunched toward the top of the flowering culm.

Photo by Kevin Doyle, 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