Carex limosa

L.

Mud Sedge

G5Secure Found in 28 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.143035
Element CodePMCYP037K0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
IUCNLeast concern
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderCyperales
FamilyCyperaceae
GenusCarex
Other Common Names
Carex des bourbiers (FR) mud sedge (EN)
Concept Reference
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-07-10
Change Date1984-02-29
Edition Date2025-07-10
Edition AuthorsSoteropoulos (2025)
Threat ImpactUnknown
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Number of Occurrences> 300
Rank Reasons
Carex limosa is a wide-ranging perennial graminoid in open wetland habitats, including sphagnum bogs, wet meadows, and shores. It has a circumboreal distribution, occurring in Eurasia and North America from Alaska, United States and throughout Canada south to New Jersey west to Nebraska, New Mexico, and Utah west to California in the United States. There are thousands of occurrences, which face threats from development, grazing and trampling by livestock, rights-of-way maintenance, recreational activities, hydrological alteration, and invasive species. Little is known about trends, but with a large range extent and large number of occurrences, abundant habitat, and broad habitat preferences, this species is considered secure.
Range Extent Comments
Carex limosa has a circumboreal distribution, occurring in Eurasia and North America from Alaska, United States and throughout Canada south to New Jersey west to Nebraska, New Mexico, and Utah west to California in the United States (FNA 2002). Range extent was estimated to be over 70 million square kilometers using herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025 (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Occurrences Comments
By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025, it is estimated that there are thousands of occurrences rangewide (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Threat Impact Comments
Although threats are not widely documented, this species is threatened by development, grazing and trampling by livestock, rights-of-way maintenance, recreational activities (especially off-road vehicles), hydrological alteration, invasive species, and other threats in some places, though there is insufficient data, including anecdotal accounts, to understand scope and severity of threats for this species (NatureServe 2025). However, their overall impact is likely negligible given the species' broad range and large number of occurrences.
Ecology & Habitat

Description

From CNHP Wetland Guide 2012: Habit: culms arising singly or few together, rhizomes slender, scaly, roots covered with yellowish-brown tomentum. Culms: slender, sharply triangular, reddish at base, 2-6 dm tall, exceeding the leaves, usually aphyllopodic, old leaves present. Leaves: 1-3 Blades: deeply channeled, somewhat glaucous, gray green, 1-3 mm wide. Sheaths: thin, hyaline ventrally, shallowly concave at mouth, lower sheaths sometimes slightly filamentose.
Bracts: lowest narrowly leaf-like or occasionally setaceous, sheathless or short-sheathed, brown-auricled, 2-10 cm long, the upper reduced. Spikes: 2-4, reddish to yellowish brown on long, nodding peduncles. Terminal spike is staminate, erect or drooping, linear, 1-3 cm long, 2.5 mm wide. Lateral spike is pistillate, nodding, 1-2.5 cm long, 5-8 mm wide, not crowded, perigynia appressed or ascending to spreading. Pistillate Scales: variable, commonly ovate to suborbicular, short-tapering, obtuse or cuspidate at apex, narrower and shorter than perigynia to nearly equaling them, yellowish brown to dark reddish brown with a green 1 to 3 nerved center. Perigynia: broadly ovoid, somewhat compressed, rounded-truncate and substipitate at base, rounded at apex or broadly tapering to a very shrot conic tip, densely papillate (minute protrusions), yellowish green or glaucous green, 2.3-4.2 mm long, 2 mm wide. Nerves: 4-7 evident on each face, margin. Beaks: Stigmas: 2

Diagnostic Characteristics

From CNHP Wetland Guide 2012: Main Characteristics:
Staminate spikes, nodding or erect 1-3 cm long; pistillate spikes, nodding 1-2.5 cm long
Culm base reddish with long lower bract up to 10 cm long
Leaves are channeled
Pistillate scales are as broad as or broader than perigynium, scales are equal to or barely exceeding perigynium length

Habitat

Carex limosa grows in sphagnum bogs, wet meadows, and shores (FNA 2002).
Palustrine Habitats
HERBACEOUS WETLANDBog/fen
Other Nations (2)
CanadaN5
ProvinceRankNative
Island of NewfoundlandS5Yes
AlbertaS4Yes
Yukon TerritoryS5Yes
New BrunswickS4Yes
NunavutS4Yes
Prince Edward IslandS3Yes
SaskatchewanS4Yes
QuebecS5Yes
Nova ScotiaS4Yes
OntarioS5Yes
Northwest TerritoriesS4Yes
LabradorS5Yes
British ColumbiaS5Yes
ManitobaS5Yes
United StatesN5
ProvinceRankNative
MontanaS3Yes
PennsylvaniaS2Yes
MassachusettsS2Yes
ColoradoS3Yes
WisconsinSNRYes
New HampshireSNRYes
ConnecticutS1Yes
New MexicoSNRYes
UtahS3Yes
NevadaS1Yes
CaliforniaS3Yes
IowaSHYes
North DakotaS2Yes
NebraskaS1Yes
WyomingS3Yes
OhioS1Yes
Rhode IslandSHYes
VermontS4Yes
AlaskaSNRYes
IdahoS3Yes
New JerseyS1Yes
New YorkS5Yes
IndianaS1Yes
WashingtonSNRYes
DelawareSXYes
MichiganSNRYes
MaineSNRYes
MinnesotaSNRYes
IllinoisS1Yes
OregonSNRYes
Threat Assessments

Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (28)
California (7)
AreaForestAcres
Black CinderLassen National Forest239
Bucks LakePlumas National Forest680
Castle PeakTahoe National Forest14,974
Chips CreekPlumas National Forest12,940
DardanellesEldorado National Forest8,110
Raymond PeakEldorado National Forest2,518
Trail LakeLassen National Forest1,124
Colorado (1)
AreaForestAcres
San MiguelSan Juan NF64,263
Minnesota (1)
AreaForestAcres
Hegman LakesSuperior National Forest675
Nevada (2)
AreaForestAcres
Copper Mtns.Humboldt-Toiyabe National Forest31,945
Jarbidge - Coon CkHumboldt-Toiyabe National Forest866
Oregon (8)
AreaForestAcres
Bull Of The WoodsMt. Hood National Forest8,843
French Pete (a)Willamette National Forest1,668
Lake ForkWallowa-Whitman National Forest21,936
Lick CreekWallowa-Whitman National Forest1,956
Maiden PeakDeschutes National Forest26,432
Maiden PeakWillamette National Forest9,627
Waldo - FujiWillamette National Forest15,273
Waldo - MoolackWillamette National Forest1,183
Washington (7)
AreaForestAcres
Big Lava BedGifford Pinchot National Forest19,043
EntiatWenatchee National Forest72,617
Grassy TopIdaho Panhandle National Forests13,485
Harvey CreekColville National Forest10,140
Mt. Baker NorthMt Baker-Snoqualmie National Forest16,873
Pasayten RimOkanogan National Forest17,074
Rock CreekWenatchee National Forest32,239
Wyoming (2)
AreaForestAcres
Rock CreekMedicine Bow-Routt National Forest18,874
Snowy RangeMedicine Bow-Routt National Forest29,660
References (7)
  1. Flora of North America Editorial Committee (FNA). 2002b. Flora of North America north of Mexico. Vol. 23. Magnoliophyta: Commelinidae (in part): Cyperaceae. Oxford Univ. Press, New York. xxiv + 608 pp.
  2. Global Biodiversity Information Facility (GBIF). 2025. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2025).
  3. iNaturalist. 2025. Online. Available: https://www.inaturalist.org (accessed 2025).
  4. Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
  5. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  6. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  7. Southwest Environmental Information Network (SEINet). 2025. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2025).