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Montana Field Guides

Rolland's bulrush - Trichophorum pumilum
Other Names:  Scirpus pumilus, Scirpus rollandii

Species of Concern
Native Species

Global Rank: G5
State Rank: S3
(see State Rank Reason below)
State Threat Score: No Known Threats
CCVI: Highly Vulnerable
C-value: 10

Agency Status


External Links

State Rank Reason (see State Rank above)
Rare in Montana, where it is currently documented from only a few calcareous fens near the Rocky Mtn Front.
General Description
Caespitose. Stems terete, 5–25 cm, clustered on thin rhizomes. Leaf blades ca. 0.5 mm wide. Spikelet 3–4 mm long with 3 to 6 flowers; awn of lowest bract shorter than the spikelet. Scales 2.5–3.5 mm long, glabrous, brown with a pale midstripe; tip rounded. Flowers: bristles absent. Achene 1.5–2 mm long (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Fruiting in July.

Diagnostic Characteristics
After mid-summer, Trichophorum pumilum looks like a tiny stick with a few little black eggs glued on top. It is most likely confused with species of Eleocharis, but in these species, the base of the style is enlarged, and the scales are persistent. Trichophorum cespitosum is a larger plant that forms distinctive tussocks. A hand lens will be necessary for positive identification.

In botanical keys,Trichophorum pumilum and Amphiscirpus nevadensis may key closely.

Rolland's Bulrush - Trichophorum pumilum, Native, SOC
*Perianth Bristles: 0; absent.
*Achene: Tipped with a skinny, short beak (style). Subtended by a scale.
*Scales: Apiculate.
*Spikelets: Solitary, 3-7 mm long. Spikelet is not subtended by a leaf-like bract.
*Stems: Round, less than 15 cm tall.
*Leaves: Less than 0.5 mm wide.
*Habitat: Hummocks in calcareous fens.

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


Range Comments
Circumboreal south to CA and WY. Known from Glacier and Teton counties (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Observations in Montana Natural Heritage Program Database
Number of Observations: 17

(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)

Calcareous fens in the foothills.
Predicted Suitable Habitat Model

This species has a Predicted Suitable Habitat Model available.

To learn how these Models were created see

Ecological Systems Associated with this Species

Threats or Limiting Factors
Threat impact not assigned because threats are not known (MTNHP Threat Assessment 2021).

  • 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?
    • Fertig, W. and G. Jones. 1992. Plant communities and rare plant species of the Swamp Lake Botanical Area, Clark's Fork Ranger District, Shoshone National Forest. Unpublished report to the Shoshone National Forest. Challenge Cost Share Agreement No. CSA-2-91-14-0001. Wyoming Natural Diversity Database. 113+ pp.
    • Lesica, P. 1991. Noteworthy Collections in Montana....
    • Lesica, P. 1991. The Rare Vascular Plants of Pine Butte Swamp Preserve. Unpublished Report to the Nature Conservancy. 15 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.
  • Web Search Engines for Articles on "Rolland's bulrush"
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Citation for data on this website:
Rolland's bulrush — Trichophorum pumilum.  Montana Field Guide.  .  Retrieved on , from