scouring rush horsetail

(Equisetum hyemale ssp. affine)

Conservation Status
scouring rush horsetail
  IUCN Red List

not listed


N5? - Secure

SNR - Unranked


not listed

Wetland Indicator Status
  Great Plains

FACW - Facultative wetland


FACW - Facultative wetland

  Northcentral & Northeast

FAC - Facultative


Scouring rush horsetail is an erect, evergreen, unbranched perennial that rises from rhizomes. It can be 8 to 60 tall, though in Minnesota it is usually 24 to 48 tall. It often forms dense colonies.

The stems are erect, to ½ in diameter, dark green, and hollow. They are normally unbranched, but may develop one or a few branches after injury, or in the second year. They have 14 to 50 fine, vertical ridges with silica deposits making them rough to the touch. They are evergreen, lasting more than one year. The central cavity is at least ¾ the diameter of the stem. The portion of the stem between the nodes is up to several inches near the bottom, becoming progressively shorter as they ascend the stem.

The leaves are reduced in size, fused together for most of their length, and appressed against the stem, forming a collar-like sheath around the nodes. The main sheaths are tan, grayish, or white, with a black band at both the base and the tip. They are wider than long, 3 16 to long, to ¾ wide, and appear squarish. At the tip of the sheath are 14 to 50 free, 3 16 long or less lobes appearing as tiny, black teeth. The teeth are jointed and may fall off at the joint at maturity, leaving just a dark rim on the sheath, but they often persist.

A solitary, spore-bearing cone is borne at the end of each fertile stem. The cone is to 1 long, circular in cross-section, and elliptic in long section. It ends with a small but conspicuous, abrupt, flexible point at the tip (apiculate). Infertile stems are similar to fertile stems but lack the terminal cone. The cone falls off after releasing spores.




8 to 60


Similar Species


Smooth scouring rush (Equisetum laevigatum) is a shorter plant, only reaching 12 to 36 tall. The stems are lighter green, smooth to the touch, and annual. The sheaths are light green and have a black band at the tip only, sometimes also the lowest ones with a black band at the base or black throughout. The teeth on the sheath fall off promptly at maturity. The cones are inconspicuously apiculate.

Variegated scouring rush (Equisetum variegatum ssp. variegatum), is a much shorter plant, only 4 to 18 tall. The stems are much thinner, 1 32 to 3 32 in diameter. The sheaths are green with a black band at the tip, and slightly flared outwards at the tip. There are 5 to 12 vertical ridges on the stem and the same number of teeth on the sheath. The teeth have conspicuous white margins. They are not jointed. The cone is shorter, long or less. It is found only in the upper third of the state.


Moist. Roadsides, woodlands, riverbanks, streambanks, lakeshores, and other moist or wet places.






Pests and Diseases




The stems are unbranched or have few irregular branches. They are coated with an abrasive silica, and were used for scrubbing cooking pots. This, along with their rush-like appearance, gave rise to the common name “scouring rush”.


Distribution Map



2, 3, 4, 5, 7, 28, 29, 30.









  Kingdom Plantae (green algae and land plants)  
  Subkingdom Viridiplantae (green plants)  
  Infrakingdom Streptophyta (land plants and green algae)  
  Superdivision Embryophyta (land plants)  
  Division Tracheophyta (vascular plants)  
  Subdivision Polypodiophytina  
  Class Polypodiopsida (ferns)  
  Subclass Equisetidae (horsetails)  


Equisetales (horsetails)  


Equisetaceae (horsetail)  


Equisetum (horsetails)  
  Subgenus Hippochaete (scouring rushes)  
  Species Equisetum hyemale (tall scouring rush)  

Monotypic genus, family, and order
There are 15 species of Equisetum, which is the only living genus in the family Equisetaceae, which is the only family in the order Equisetales, which is the only order in the class Equisetopsida.

The genus Equisetum is divided into two subgenera, Equisetum and Hippochaete. Field horsetail is one of the eight species in the subgenus Equisetum. Six of those eight species are found in North America. Five are found in Minnesota.

Living fossil
The history of Equisetum has been traced 300 million years to the Cretaceous period, and possibly to the Triassic period. That could make Equisetum the oldest living genus of vascular plants.


Subordinate Taxa






Equisetum affine

Equisetum hyemale var. affine

Equisetum hyemale var. californicum

Equisetum hyemale var. pseudohyemale

Equisetum hyemale var. robustum

Equisetum praealtum

Equisetum praealtum var. affine

Equisetum prealta var. affinis

Equisetum robustum

Equisetum robustum var. affine

Hippochaete hyemalis

Hippochaete hyemalis ssp. affinis


Common Names


common scouring rush

Dutch rush

rough horsetail

scouring rush

scouring rush horsetail

scouringrush horsetail


stout scouringrush

tall scouring rush

western scouring rush

winter scouring rush













Ending in a short, abrupt, flexible point.



The small swelling of the stem from which one or more leaves, branches, or buds originate.



A horizontal, usually underground stem. It serves as a reproductive structure, producing roots below and shoots above at the nodes.

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    scouring rush horsetail   scouring rush horsetail  






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Other Videos
  Horsetail or Scouring Rush - Helpful Hints from Jas. Townsend and Son
Jas. Townsend and Son, Inc.

Published on Oct 14, 2013

An interesting episode on a useful plant that was popular in the 18th and 19th century. Make sure to check out our website at

  How to tell if your plant is a horsetail
newenglandwild's channel

Published on Jan 16, 2013

This video tells you how to see if your mystery plant is a horsetail or scouring rush -- a member of the genus Equisetum.

  Equisetum hyemale releases spores
Robert Klips

Published on Jun 26, 2012

Scouring rush, Equisetum hyemale, which ought to be called "tube fern" because it is quite closely related to ferns, beares its spores in sporangia at the edges of hexagonal sporophylls that are arranged in a cone-like stobilus. Spore release and dispersal is aided by appendages called "elaters" that unfurl with changes in humidity.




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Afton State Park

Agassiz Dunes SNA (MN DNR)

Beaver Creek Valley State Park

Belgium Prairie

Blanket Flower Prairie SNA

Buffalo River State Park

Bunker Hills Regional Park

Camden State Park

Cannon River Trout Lily SNA

Cannon River Turtle Preserve SNA

Carpenter St. Croix Valley Nature Center

Charles A. Lindbergh State Park

Clifton E. French Regional Park

Crow Wing State Park

Crystal Spring SNA

Des Moines River SNA

Elm Creek Park Reserve

Falls Creek SNA

Felton Prairie SNA, Bicentennial Unit

Felton Prairie SNA, Shrike Unit

Flandrau State Park

Franconia Bluffs SNA

Glacial Lakes State Park

Glendalough State Park

Hastings Sand Coulee SNA

Hemlock Ravine SNA

Hole-in-the-Mountain Prairie

Holthe Prairie SNA

Iron Horse Prairie SNA

John A. Latsch State Park

John Peter Hoffman Spring Brook Valley WMA

Lake Bronson State Park

Lake Carlos State Park

Lawrence Creek SNA

Maplewood State Park

Miesville Ravine Park Reserve

Mille Lacs Kathio State Park

Minnesota Valley NWR, Rapids Lake Unit

Minnesota Valley NWR, Wilkie Unit

Mississippi River County Park

Nerstrand Big Woods State Park

North Fork Zumbro Woods SNA

Old Mill State Park

Otter Tail Prairie SNA

Oxbow Park & Zollman Zoo

Pankratz Memorial Prairie, North Unit

Pembina Trail Preserve SNA, Pembina Trail Unit

Phelps Lake WMA

Pin Oak Prairie SNA

Prairie Smoke Dunes SNA

Red Rock Prairie

Regal Meadow

Rice Lake Savanna SNA

Richard M. & Mathilde Rice Elliott SNA

River Terrace Prairie SNA

Roscoe Prairie SNA

St. Croix State Park

Sakatah Lake State Park

Sand Prairie Wildlife Management and Environmental Education Area

Seminary Fen SNA

Seven Mile Creek County Park

Seven Sisters Prairie

Spring Creek Prairie SNA

Staffanson Prairie

Thorson Prairie WMA

Twin Valley Prairie Addition

Vermillion River WMA

Wahpeton Prairie WMA

Western Prairie SNA

Whitetail Woods Regional Park

Whitewater State Park

Wild River State Park

William O’Brien State Park

Wolsfeld Woods SNA

Woodland Trails Regional Park

Zimmerman Prairie

Zumbro Falls Woods SNA







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