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Montana Field Guide

Montana Field Guides

Variegated Horsetail - Equisetum variegatum

Native Species

Global Rank: G5
State Rank: S4
C-value: 5

Agency Status


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General Description
Stems monomorphic with 3 to 12 ridges, evergreen, 6–30 cm × 1–3 mm, branched at the base, erect or ascending. Sheaths green with a terminal black band, teeth white with a black center and hair-like tip. Strobili 5–10 mm long with a sharp-pointed tip, maturing in summer. Our plants are subspecies variegatum (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Diagnostic Characteristics
Stems evergreen, stomata borne in lines, 2 to each furrow. Stems with a central cavity and 5 or more vallecular cavities. Stems 5-12 ridged, teeth of sheaths persistant.

Species Range
Montana Range Range Descriptions


Range Comments
Western MT with disjunct occurrences in Phillips and Garfield counties; circumpolar south to OR, UT, IL and NY (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Observations in Montana Natural Heritage Program Database
Number of Observations: 27

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density



(Observations spanning multiple months or years are excluded from time charts)

Wet, often calcareous, gravelly soil along seeps, streams, lakes at all elevations (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

  • Literature Cited AboveLegend:   View Online Publication
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Bissell, J.K. & C.W. Bier. 1987 Dec 30. Presque Isle State Park: Botanical Survey and Natural Community Classification. U87BIS02.
    • Cobb, B. 1963. A Field Guide to the Ferns. Houghton Mifflin Company, Boston, USA. B63COB01PAUS
    • Eggers, M.J.S. 2005. Riparian vegetation of the Montana Yellowstone and cattle grazing impacts thereon. M.Sc. Thesis. Montana State University, Bozeman, MT. 125 p.
    • Fernald, M. L. 1950. Gray's manual of botany. Eighth edition. A handbook of the flowering plants and ferns of the central and northeastern United States and Adjacent Canada. American Book Co., New York.
    • Gleason, H.A. 1952. New Britton & Brown. Illustrated Flora. Lancaster Press Inc. Lancaster, Pa. B52GLE01PAUS
    • Hauke, R.L. 1963. A taxonomic Monograph of the Genus Equisetum Subgenus Hippochaete. C.B. Stuttgart. Weinheim GER. B63HAU01PAUS
    • Hauke, R.L. 1983. Horsetails (Equisetums) in North America. Fiddlehead Forum 10:39-43. A83HAU01PAUS
    • Lellinger, D.B. 1985. A Field Manual of the Ferns and Fern-Allies of the United States and Canada. Smithsonian Inst. Press. Washington, D.C. B85LEL01PAUS
    • Montgomery, J.O. 1981. Equisetum variegatum and Equisetum x trachydon. American Fern Journal 71:1-2. A81MON01PAUS
    • Schaffner, J.H. 1921. North American species of Equisetum North of Mexico. American Fern Journal 11:65-75. A21SCH01PAUS
    • Wherry, E.T. 1940-1941. The Ferns and Lycosphenes of Pennsylvania. Bartonia 21:11-37. A40WHE01PAUS
  • Web Search Engines for Articles on "Variegated Horsetail"
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Citation for data on this website:
Variegated Horsetail — Equisetum variegatum.  Montana Field Guide.  .  Retrieved on , from