Tufted Club-rush - Trichophorum cespitosum
Scirpus cespitosus, Trichophorum caespitosum
State Rank Reason (see State Rank above)
Rare in Montana, where it is currently documented from over a dozen fens and wet meadows in the mountainous portion of western Montana.
- Details on Status Ranking and Review
Score1 - Moderate: Generally 10,000-100,000 individuals.
Score1 - Peripheral, Disjunct or Sporadic Distribution in MT: Widespread species that is peripheral, disjunct or sporadically distributed within MT such that it occurs in <5% of the state (<7,500 sq. miles or the combined area of Beaverhead and Ravalli Counties) or is restricted to 4-5 sub-basins.
Area of Occupancy
Score1 - Moderate: Generally occurring in 11-25 Subwatersheds (6th Code HUC’s).
Score2 - High: Species is restricted to a highly specialized and limited habitat and is typically dependent upon unaltered, high-quality habitat (C Values of 8-10).
Score0-1 - Stable to Minor Declines:
CommentTrends unknown, though populations are likely stable or experiencing only minor declines.
Score0-1 - Low to Medium.
Score0-1 - Low to Moderate Vulnerability.
Raw Conservation Status Score
5 to 8 total points scored out of a possible 19.
Plants forming large hemispheric tussocks. Stems terete, 10–40 cm, densely clustered. Leaf blades reduced to scales at the base, often with 1 short blade on the lower stem, 1 mm or less wide. Spikelet 3–6 mm long with 2 to 4 flowers; awn of lowest bract barely longer than the spikelet. Scales 3–4 mm long, glabrous, brown, apiculate. Flowers: bristles 6, brown, barely exceeding the scale awn. Achene ca. 1.5 mm long (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX
Mature fruit in July-August.
Trichophorum cespitosum could easily be mistaken for a species of Eleocharis; however, the former has spikelets subtended by a short-awned scale, whereas the latter do not. It resembles T. alpinum except for its smooth, round stems, and resembles T. pumilum except that it forms large, distinctive tussocks and has perianth bristles.
Circumboreal south to OR, ID, UT and MT (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
Wet meadows and sphagnum-dominated fens in the montane to alpine zones.
Ecological Systems Associated with this Species
Threats or Limiting Factors
STATE THREAT SCORE REASON
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?
- Lesica, P. 1991. The Rare Vascular Plants of Pine Butte Swamp Preserve. Unpublished Report to the Nature Conservancy. 15 Pp.
- Lesica, P. 1992. Monitoring the Scirpus cespitosis - Scirpus acutus ecotone at Pine Butte Swamp Preserve. The Nature Conservancy, Montana Field Office, Helena, Montana. 9 pp.