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Montana Field Guide

Montana Field Guides

Soft Rush - Juncus effusus
Other Names:  Common Rush, Juncus pylaei, Juncus communis

Non-native Species

Global Rank: G5
State Rank: SNA
(see State Rank Reason below)
C-value: 6

Agency Status


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State Rank Reason (see State Rank above)
Plants in Montana are Juncus effuses ssp. effusus. This subspecies is an aggressive introduced species from Europe, and has colonized in British Columbia and Idaho (Zika 2003).
General Description
Short-rhizomatous, caespitose. Stems erect, terete, hollow, 40–100 cm. Leaves mainly basal; blades reduced to a bristle; auricles absent; sheaths purple to brown. Inflorescence open or congested with numerous, pedicellate flowers; bract terete, erect, appearing like a continuation of the stem. Flowers with prophylls; tepals brown with green midvein, 2–3 mm long, acuminate; stamens 3. Capsules ca. 2 mm long, truncate on top; seeds apiculate (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Our plants are subspecies effusus, which is introduced from Europe. J. effusus ssp. effusus is distinguished by thin, green, symmetrical upper sheaths that are less than 14 centimeters long and have overlapping margins in the upper third. Also, this subspecies has spreading tepals (Zika 2003). See Zika 2003 for comparative illustrations and a key.

Species Range
Montana Range Range Descriptions


Range Comments
BC to MT south to CA, northeast North America, Europe (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Observations in Montana Natural Heritage Program Database
Number of Observations: 53

(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)



  • Literature Cited AboveLegend:   View Online Publication
    • Douglas, G.W., D. Meidinger, and J. Pojar, editors. 2001. The Illustrated Flora of British Columbia. Volume 6. Monocotyledons (Acoraceae through Najadaceae). British Columbia Ministry of Environment, Lands and Parks and British Columbia Ministry of Forests, Victoria.
    • Hurd, E.G., S. Goodrich, and N.L. Shaw. 1997. Field Guide to Intermountain Rushes. General Technical Report INT-306. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 56 pp.
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
    • McGregor, R.L. (coordinator), T.M. Barkley, R.E. Brooks, and E.K. Schofield (eds). 1986. Flora of the Great Plains: Great Plains Flora Association. Lawrence, KS: Univ. Press Kansas. 1392 pp.
    • Sturm, J. and J.G. Sturm. 1796. Deutschlands Flora in Abbildungen (nur Tafeln). Stuttgart, Germany. 882 pp.
    • Zika, P.F. 2003. The native subspecies of Juncus effusus (Juncaceae) in western North America. Brittonia 55(2): 150-156.
  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Britton, N. L. and A. B. Brown. 1913. An Illustrated Flora of the Northern United States, Canada, and the British Possessions. 2nd Edition in 3 Volumes. New York, NY: Charles Scribner's Sons. B13BRI01PAUS.
    • Culver, D.R. 1994. Floristic analysis of the Centennial Region, Montana. M.Sc. Thesis. Montana State University, Bozeman. 199 pp.
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2022. Manual of Montana Vascular Plants, Second Edition. Fort Worth, TX: BRIT Press. viii + 779 p.
    • Tuinstra, K. E. 1967. Vegetation of the floodplains and first terraces of Rock Creek near Red Lodge, Montana. Ph.D dissertation. Montana State University, Bozeman 110 pp.
  • Web Search Engines for Articles on "Soft Rush"
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Citation for data on this website:
Soft Rush — Juncus effusus.  Montana Field Guide.  .  Retrieved on , from