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Montana Field Guides

Many-headed Sedge - Carex sychnocephala

Species of Concern
Native Species

Global Rank: G5
State Rank: S1S2
(see State Rank Reason below)
State Threat Score: High - Medium
C-value: 8

Agency Status


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State Rank Reason (see State Rank above)
Currently known in the state from three occurrences that are believed to be extant. Also, known from one 1891 collection near Great Falls and two locations in northwest Montana now believed to be extirpated or severly impacted as a result of wetland draining and construction of a dock. The remaining populations are on the Blackfeet Indian Reservation and a Nature Conservancy Preserve. Due to the habitats in which the species grows, it is vulnerable to development and hydrologic alterations.
General Description
Caespitose. Stems erect, 5–50 cm. Leaves basal and cauline; blades 1–3 mm wide. Inflorescence of 4 to 12 sessile spikes in a dense head; lower bracts erect, much longer than the inflorescence. Spikes 4–8 mm long, all similar; female flowers above few male. Perigynia erect, linear-lanceolate, green to tan, wing- and serrulate-margined, 3–6.5 × 0.8–1 mm, tapered to the serrulate beak, 3–5 mm long; stigmas 2. Female scales lanceolate, acuminate, tan-hyaline with a green midvein, shorter or longer than the perigynia. Achene 2-sided, smaller than the perigynium (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Fruit mature in July-August.

Diagnostic Characteristics
The combination of long, leaf-like lower bracts, and long, narrow perigynia is distinctive.

Species Range
Montana Range Range Descriptions


Range Comments
AK to QC south to WA, CO, MO and NY (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Observations in Montana Natural Heritage Program Database
Number of Observations: 10

(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)

Moist soil of meadows along streams and ponds in the valleys and on the plains.
Predicted Suitable Habitat Model

This species has a Predicted Suitable Habitat Model available.

To learn how these Models were created see

Threats or Limiting Factors
Reported threats to Montana's populations of Many-headed Sedge concern factors presumably responsible for extinction of two populations. One population was destroyed where a dock was constructed. Another population was lost where a wetland was drained to expand agricultural use. Hydrological alteration actions that dewater or inundate Many-headed Sedge habitat pose a threat to several populations located where it is employed for agricultural benefit. Remaining populations occur in places where it may be desirable for development or agricultural expansion which would displace plants and/or fragment populations and further habitat degradation (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?
    • Heidel, B.L., S.V. Cooper and C. Jean. 2000. Plant species of special concern and plant associations of Sheridan County, Montana. Report to U.S. Fish and Wildlife Service. Montana Natural Heritage Program, Helena, Montana. 96 p.
    • Hermann, F. J. 1970. Manual of the Carices of the Rocky Mountains and Colorado Basin. Agricultural Handbook No. 374. USDA Forest Service. 397 pp.
    • Lesica, P. and J. S. Shelly. 1988. The vegetation and flora of glaciated prairie potholes on the Blackfeet Indian Reservation, Montana: Progress report. Unpublished report to the Montana Nature Conservancy, Helena, MT. 19 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 "Many-headed Sedge"
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Citation for data on this website:
Many-headed Sedge — Carex sychnocephala.  Montana Field Guide.  .  Retrieved on , from