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Montana Field Guides

Three-square Bulrush - Schoenoplectus pungens
Other Names:  Scirpus pungens

Native Species

Global Rank: G5
State Rank: S5
C-value: 6


Agency Status
USFWS:
USFS:
BLM:


 

External Links






 
General Description
Stems 3-sided, 10–200 cm. Leaf blades flat or folded, 1–4 mm wide. Inflorescence compact, of 1 to 6 sessile spikelets. Spikelets 7–20 mm long. Scales 3–6 mm long, glabrous, light brown to blackish; awn bent, 0.5–2 mm long. Flowers: bristles 4 to 8, shorter to as long as the achene; stigmas 2 or 3. Achene 2- or 3-sided, brown, ca. 3 mm long (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Diagnostic Characteristics
Three-square Bulrush - Schoenoplectus pungens, native
*Perianth Bristles: 4-8, short to as long as the achene.
*Achene: Tipped with a skinny, short beak (style) that is not triangular or thickened.
*Scales: Awn bent, 0.5-2 mm long.
*Spikelets: Sessile, 6-12 mm long. Solitary, but usually some plants have at least 2 spikelets. Always with 1 long, leaf-like bract subtending the spikelets.
*Stems: Triangular, and often taller than Nevada Clubrush. Has internal cavities.
*Leaves: up to 4 mm wide.
*Habitat: saline or alkaline wetlands; inundated or not.

Nevada Clubrush - Amphiscirpus nevadensis, Native, SOC
*Perianth Bristles: 1-6, inconspicuous and shorter than the achene.
*Achene: Not tipped with a beak; style absent. Subtended by a scale.
*Scales: Awn absent.
*Spikelets: Solitary, but usually some plants have at least 2 spikelets; 6-12 mm long. Always with 1 long, leaf-like bract below (subtended) the spikelets.
*Stems: Round, wiry, and erect. Lacks internal cavities.
*Leaves: Basal and on lower stem, 0.5-2.0 mm wide.
*Habitat: Moist to wet alkaline wetlands, but not aquatic.

Species Range
Montana Range

Year-round
 


Range Comments
Throughout temperate North America to S. 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: 160

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

Recency

 

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



Habitat
Usually saline or alkaline, wet meadows, marshes; plains, valleys (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

References
  • 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?
    • 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.
  • Web Search Engines for Articles on "Three-square Bulrush"
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Citation for data on this website:
Three-square Bulrush — Schoenoplectus pungens.  Montana Field Guide.  .  Retrieved on , from