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Slender Bulrush (Schoenoplectus heterochaetus)

Life history

Species overview

Slender Bulrush (Schoenoplectus heterochaetus), a Wisconsin Special Concern plant, is found along margins of freshwater lakes and streams. Fruiting occurs June through August. The optimal identification period for this species is late July through late August.

Synonyms: Scirpus heterochaetus, Scirpus lacustris, Scirpus lacustris ssp. lacustris var. tenuiculmis, Scirpus lacustris var. tenuiculmis, Scirpus tenuiculmis


  • Distinguishing characteristics: Mainly with 3 carpels; spikelets mostly or all individually pedicellate.
  • Flower characteristics: Inflorescence loose and lax, most or all of the spikelets individually pedicellate; spikes light to medium brown; flowers mostly with three carpels; styles 3-parted.
  • Fruit characteristics: Achene unequally three-angled.
  • Leaf characteristics: Few leaves, mainly or all towards the base, commonly with prominent, well developed sheath and short, poorly developed blade (or bladeless).


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


  • Growth form: Graminoid
  • Vegetative reproduction: Rhizomatous
  • Life cycle: Perennial
  • Comments: Associated Species: Scirpus sp., Naias flexilis, Ceratophyllum demersum.

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 Slender Bulrush (Schoenoplectus heterochaetus). 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 Schoenoplectus heterochaetus in the Natural Heritage Inventory Database as of July 2015.

Summary Information
State StatusSC
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 along margins of freshwater lakes and streams.
  • Soils: Wet soils.

Natural communities

This table lists the natural communities that are associated with Slender Bulrush. 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
Emergent Marsh 3

Ecological landscapes

This table lists the ecological landscape association scores for Slender Bulrush. 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.

  • No avoidance measures have been developed for this species.

Management guidance

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

  • No guidance has been developed for this species.


Slender Bulrush Photo.

Specimen scanned by the Wisconsin Herbarium, Madison, WI.

Scanned specimen courtesy of Wisconsin Herbarium

Slender Bulrush Photo.

Specimen scanned by the Wisconsin Herbarium, Madison, WI.

Scanned specimen courtesy of Wisconsin Herbarium

Slender Bulrush Photo.

Photo ©  USDA-NRCS.

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