Equisetum laevigatum

Smooth Scouring Rush

Smooth Scouring Rush, Photo courtesy  Wisconsin State Herbarium and  Michael Clayton
Smooth Scouring Rush
Photo courtesy Wisconsin State Herbarium and Michael Clayton

Flora, fauna, earth, and sky...
The natural history of the northwoods


  • Equisetum, from the Latin, equus, "horse", and seta, "bristle, animal hair"
  • laevigatum, from the Latin, "smooth, slippery"
  • Common name from the surface texture relative to the other Scouring Rushes.
  • Other common names include Smooth Horsetail, Bakushi, Kawasíola (Tarahumara), Naks r bhai Baapak (Tepehuán), Cola de caballo, Tuti (Mex)


  • Kingdom Plantae, the Plants
    • Division Equisetophyta, the Horsetails
      • Class Equisetopsida, the Horsetails
        • Order Equisetales, the Horsetails
          • Family Equisetaceae, the Horsetails
            • Genus Equisetum, the Horsetails
  • Taxonomic Serial Number: 17156
  • Also known as Equisetum funstonii, Equisetum kansanum, Hippochaete laevigata


  • Stem erect, green, annual, jointed, grooved with 10-32 ridges, smooth, usually unbranched, up to 5' tall.
  • Leaf Sheath green, elongate, 7-15×3-9mm; leaves reduced to 10-32 tiny, black teeth with white borders, triangular scales encircling the stem at each joint, usually shed early, leaving dark rim on sheath.
  • Cone up to 1" long, somewhat broader than stem, with rounded, blunt tip, capped with small, needle-like point.
  • Spores green, spheric.


  • Identifiable as a Horsetail by the upright, hollow, jointed, cylindrical stems with inconsequential and easily overlooked leaves.
  • Distinguished from similar, unbranched Horsetails (Scouring Rushes) by its smooth stems and needle-tipped cones
    • Common Scouring Rush (Equisetum hyemale), also known as Rough Scouring Rush or Rough Horsetail, has a rougher surface and distinctive, ashy grey bands at stem joints.
    • Variegated Scouring Rush (Equisetum variegatum), shows a distinct white margin at the stem joints, hence "variegated"
  • Field Marks
    • nearly smooth stems
    • pointed cones


  • British Columbia to Québec, south to Baja California, Northern Mexico, Texas, Arkansas, Missouri, Illinois, Indiana, and Ohio.


  • Moist prairies, riverbanks, roadsides.
  • Typically occurs in wetlands, but occasionally found in non-wetlands






  • By spore and vegetatively by rhizome


  • By rhizome division


  • Hardy to USDA Zone 3 (average minimum annual temperature -40ºF)
  • Cultural Requirements
    • Sun to part shade
    • Constantly moist
    • Fertilization unnecessary
  • Good for bog gardens, pond margins, and naturalizing low, wet areas.
  • Can be invasive.
  • Available by mail order from specialty suppliers.



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Last Updated on 26 February, 2004