Thin-flowered Sedge - Carex tenuiflora
Species of Concern
(see State Rank Reason below)
MNPS Threat Rank
State Rank Reason (see State Rank above)
Rare in Montana, where it is currently known from only one site in Glacier National Park. The potential for negative impacts to the occurrence are minimal.
Caespitose. Stems weak, often prostrate, 20–50 cm. Leaves basal and cauline; blades ca. 1 mm wide. Inflorescence of 2 to 4 sessile, aggregated spikes; lowest bract inconspicuous. Spikes 4–6 mm long, all similar, bisexual; female flowers above. Perigynia spreading to ascending, pale green, narrowly ovoid, 3–3.5 mm long with an inconspicuous beak; stigmas 2. Female scales hyaline to tan with a green midvein, shorter than the perigynia. Achene 2-sided, filling the perigynium (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
Fruit mature in July-August.
Carex tenuiflora could be confused with two other more common peatland sedges: C. interior and C. canescens. The former has lance-shaped perigynia, and both have scales that are only half the length of the perigynia. A hand lens or microscope will be needed to observe these characters.
Circumboreal south to BC, MT, CO; collected once in Flathead County (Lesica 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, organic soil of Sphagnum-dominated fens in the montane zone.
- Additional ReferencesLegend: View Online Publication
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- Lesica, P., M. T. Lavin, and P. F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.