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Marsh Horsetail (Equisetum palustre)

Life history

Species overview

Marsh Horsetail (Equisetum palustre), a Wisconsin Special Concern plant, is found in fens, alder tickets, wet sedge meadows, bog and swamp margins, and wet swales near the Great Lakes. The optimal identification period for this species is late May through late September.

Synonyms: Equisetum palustre f. verticillatum, E. palustre var. americanum, E. palustre var. americanum f. luxurians, E. palustre var. palustre, E. palustre var. simplicissimum


  • Distinguishing characteristics: Distinguished from other species in the genus by having whorled branches in which the first internode of the branch is shorter than the adjacent sheath. Distinguished from E. fluviatile by having fewer ridges (usually less than 10) on stem.
  • Flower characteristics:
  • Fruit characteristics: Cones with peduncle, 9 to 35 mm long, blunt.
  • Leaf characteristics: Leaf-like branches occassionally in whorls at middle and upper nodes.


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


  • Growth form: Fern ally
  • Vegetative reproduction: Rhizomatous
  • Life cycle: Perennial/annual
  • Comments: Associated Species: Carex lacustris, Sphagnum spp., Calamagrostis canadensis, Larix laricina, Juncus canadensis, Thuja occidentalis.

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 Marsh Horsetail (Equisetum palustre). 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 Equisetum palustre 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 in fens, alder tickets, wet sedge meadows, bog and swamp margins, and wet swales near the Great Lakes.
  • Soils: Wet, often calcareous soils.

Natural communities

This table lists the natural communities that are associated with Marsh Horsetail. 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 Marsh Horsetail. 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

  • Avoid rapid and dramatic reductions in canopy cover or basal area in wet areas to reduce risk of swamping.
  • 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.
  • Minimize disturbance to hydrology, including soil disturbance from rutting.


Marsh Horsetail Photo.

Photo by Kevin Doyle, Wisconsin DNR.

Marsh Horsetail Photo.

Marsh horsetail has relatively few teeth per sheath, usually less than 15.

Photo by Kevin Doyle, Wisconsin DNR.

Marsh Horsetail Photo.

Note that the first internode of the branches are significantly shorter than the adjacent stem sheath.

Photo by Kevin Doyle, Wisconsin DNR.

Marsh Horsetail Photo.

Photo ©  Biopix.

Marsh Horsetail 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