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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:


 

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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 Range Descriptions

Native
 


Range Comments
Throughout temperate North America to S. America; Europe (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

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.
    • 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.
    • Sater, S. 2022. The insects of Sevenmile Creek, a pictorial guide to their diversity and ecology. Undergraduate Thesis. Helena, MT: Carroll College. 242 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