Search Field Guide
Advanced Search
MT Gov Logo
Montana Field Guide

Montana Field Guides

Lake-bank Sedge - Carex lacustris

Species of Concern
Native Species

Global Rank: G5
State Rank: S1S2
(see State Rank Reason below)
State Threat Score: Low
CCVI: Moderately Vulnerable
C-value: 9

Agency Status
USFS: Species of Conservation Concern in Forests (FLAT)


External Links

State Rank Reason (see State Rank above)
A rare species in Montana, known only from a few occurrences from Lake County.
General Description
Rhizomatous. Stems erect, 50–80 cm. Leaves basal and cauline; blades 3–12 mm wide. Inflorescence of 5 to 8 short-pedunculate spikes; the lowest bract greater than the inflorescence. Spikes unisexual, erect ascending; the uppermost 1 to 4 male, narrow, 2–3 cm long; the lower female, 2–6 cm long, cylindric. Perigynia ascending, green, broadly lanceoloid, inflated, glabrous, 5–7 mm long tapered to an indistinct beak ca. 1 mm long; stigmas 3. Female scales acute to acuminate, tan with a pale midstripe and margins, awned, smaller than the perigynia. Achene 3-sided, much smaller than the perigynium (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Species Range
Montana Range Range Descriptions


Range Comments
Valleys of Lake County; AB to QC south to ID, MT, MO and VA (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Observations in Montana Natural Heritage Program Database
Number of Observations: 12

(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)

Marshes and fens.
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 Lake-bank Sedge are limited to the potential for water management actions to inundate or divert water away from existing populations. Existing negative impacts are not known, but potential threat of damage to the small, geographically isolated population is essential to its conservation (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., 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 "Lake-bank Sedge"
Login Logout
Citation for data on this website:
Lake-bank Sedge — Carex lacustris.  Montana Field Guide.  .  Retrieved on , from