Equisetum fluviatile

Water Horsetail

Water Horsetail, Photo Courtesy USDA Plants Database
Water Horsetail
Photo Courtesy USDA Plants Database

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The natural history of the northwoods


  • Equisetum, from the Latin, equus, "horse", and seta, "bristle, animal hair"
  • fluviatile, from the Latin, fluvius, "flood"
  • Water Horsetail, from its prefered habitat
  • Other common names include Pipes, River Horsetail, Swamp Horsetail, Prêle Fluviatile (Qué), Sjöfräken, Dyfräken (Swe), Elvesnelle (Nor), Dynd-Padderok (Dan), Järvikorte (Fin), Tjarnelfting, Fergin (Is), Teich-Schachtelhalm (Ger), Clois (Gaelic), Konnaosi, Konnaoss, Jõeosi, Veeosi, Vesikuusk, (Estonian)


  • 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: 17150
  • Also known as Equisetum limosum


  • A native, perennial horsetail of shallow waters.
  • Stems alike; erect, hollow, and smooth; about 36" tall, ¼" wide. Internodes about 2" apart. Stem ridges flat and obscure; approximately 20 in number. Largest central hollow of any of our horsetails, typically occupying 80% of the stem diameter. The resulting thin walls allow for no vallecular channels (except occasionally at the base of the stem).
  • Leaf Sheaths tightly clasping, squarish, 4-10 mm long x 4-10 mm wide, green, with 12-24 narrow, 2-3 mm black teeth, occasionally with narrow white border.
  • Branches highly variable in number, if any. Ascending, whorled; smooth, slender, and hollow; length variable. First branch segment much shorter than subsequent segments.
  • Cones short stemmed and blunt tipped; about 1" long.
  • Rootstalk hollow, reddish, same size as stems; wide creeping.


  • Identifiable as horsetail by the upright, hollow, jointed, cylindrical stems with inconsequential and easily overlooked leaves.
  • Distinguished from other branched horsetails by its large central hollow and aquatic habitat.
  • Field Marks
    • smooth stem with thin wall and large central hollow
    • initial branch segment much reduced in length
    • cones borne on branched stems


  • Aleutian Islands to Newfoundland, south to Oregon, Idaho, NW Montana, NE Wyoming, West Virginia, and Virginia.
  • Eurasia south to northern Italy, China, Korea, and Japan.


  • Ponds, swamps, ditches, and other sluggish waters with mud bottoms; often fairly deep in still waters.
  • Look for in sheltered waters off lakeshore campsites, at portages.



  • Trees: Balsam Fir (Abies balsamea), Red Maple (Acer rubrum), Black Ash (Fraxinus nigra), Green Ash (Fraxinus pennsylvanica), Tamarack (Larix laricina), White Spruce (Picea glauca), Black Spruce (Picea mariana), Jack Pine (Pinus banksiana), White Pine (Pinus strobus), Balsam Poplar (Populus balsamifera), Bur Oak (Quercus macrocarpa), White Cedar (Thuja occidentalis)
  • Shrubs: Speckled Alder (Alnus incana), Leatherleaf (Chamaedaphne calyculata), Red Osier Dogwood (Cornus stolonifera), Creeping Snowberry (Gaultheria hispidula), Winterberry Holly (Ilex verticillata), Labrador Tea (Ledum groenlandicum), Twinflower (Linnaea borealis), Swamp Dewberry (Rubus pubescens), Bebb Willow (Salix bebbiana), Meadowsweet (Spiraea alba), Small Cranberry (Vaccinium oxycoccos)
  • Herbs: Water Plantains (Alisma spp.), Panicled Aster (Aster lanceolatus), Goldthread (Coptis trifolia), Joe Pye Weed (Eupatorium maculatum), Boneset (Eupatorium perfoliatum), Orange Jewelweed (Impatiens capensis), Canadian Wood Nettle (Laportea canadensis), Naked Mitrewort (Mitella nuda), Fringed Polygala (Polygala pauciflora), Arrow-leaved Tearthumb (Polygonum sagittatum), Pickerel Reed (Pontederia cordata), Arrowheads (Sagittaria spp.), Bur Reeds (Sparganium spp.), Skunk Cabbage (Symplocarpus foetidus), Cattails (Typha spp.), Stinging Nettle (Urtica dioica)
  • Grasses: Bluejoint Reed Grass (Calamagrostis canadensis), Carex lacustris, Carex lasiocarpa, Few-seeded Sedge (Carex oligosperma), Carex pauciflora, Carex pellita, Carex trisperma, Carex utriculata, Spikerush (Eleocharis palustris), Eriophorum vaginatum, Manna Grasses (Glyceria spp.), Giant Reed (Phragmites australis), Marsh Bluegrass (Poa palustris), Bulrushes (Scirpus atrovirens, Scirpus cyperinus), Wild Rice (Zizania palustris).
  • Ferns: Ostrich Fern (Matteuccia struthiopteris), Sensitive Fern (Onoclea sensibilis), Cinnamon Fern (Osmunda cinnamomea), Marsh Fern (Thelypteris palustris),
  • Ground Covers: Sphagnum Mosses (Sphagnum spp.)
  • Mammals: Horsetails and blueberries (Vaccinium spp.) are the two most important plant genera to black bears in the region.


  • The young shoots were formerly said to be eaten, dressed like asparagus, or fried with flour and butter. It is recorded that the poorer classes among the Romans occasionally ate them as a vegetable, though not particularly palatable or very nutritious.
  • According to Linnaeus, reindeer, which refuse ordinary hay, will eat this horsetail, which is about 3' high and juicy, and that it is cut as fodder in the north of Sweden for cows, with a view to increasing their milk, but that horses will not touch it.



  • Reproduces by spores and vegetatively by rhizomes
  • Primarily reproduces by vegetative means; the majority of shoots arising from rhizomes.


  • Division most successful method.


  • Hardy to USDA Zone 2 (average minimum annual temperature -50ºF)
  • Cultural Requirements
    • Light - full sun
    • Soil - heavy
    • Water - constant moisture
    • Fertilization - unnecessary
  • Good choice for pond and bog gardens.
  • Available by mail order from specialty suppliers.



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Last Updated on 26 February, 2004