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Carex subnigricans

Stacey

Dark Alpine Sedge

G4Apparently Secure Found in 2 roadless areas NatureServe Explorer →
G4Apparently SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.145401
Element CodePMCYP03D90
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderCyperales
FamilyCyperaceae
GenusCarex
Other Common Names
Dark Mountain Sedge (EN) nearlyblack 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 Date2026-04-21
Change Date2026-04-21
Edition Date2026-04-21
Edition AuthorsSoteropoulos (2026)
Threat ImpactUnknown
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences21 - 300
Rank Reasons
Carex subnigricans is a wide-ranging perennial graminoid found at high elevations, often in wetlands, in moist, rocky, alpine to subalpine slopes and meadows. It is endemic to the western United States from western Wyoming and Utah west to Oregon and High Sierra Nevada in eastern California. There are over 60, and likely over 81, occurrences, which face threats from livestock grazing, rights-of-way maintenance, recreation, grazing by nonnative mountain goats and increases in native bighorn sheep populations, drought, and climate change. Little is known about trends, but with a large range extent and large number of occurrences, this species is considered apparently secure.
Range Extent Comments
Carex subnigricans is endemic to the western United States from western Wyoming and Utah west to Oregon and High Sierra Nevada in eastern California (FNA 2002, Jepson Flora Project 2026, OSU 2026). Range extent was estimated to be over 600,000 square kilometers using herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025 (RARECAT 2025, GBIF 2026, iNaturalist 2026, NatureServe 2026, SEINet 2026).
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 over 60 occurrences rangewide (RARECAT 2025, GBIF 2026, iNaturalist 2026, NatureServe 2026, SEINet 2026).
Threat Impact Comments
This species is threatened by livestock grazing, rights-of-way maintenance, recreation (especially off-road vehicles, but also foot traffic and dispersed camping), grazing by nonnative mountain goats and increases in native bighorn sheep populations, drought, and climate change, because this species occurs at high elevation, and there are limited elevational gains for shifting habitat, though there is insufficient data, including anecdotal accounts, to understand scope and severity of threats for this species rangewide (UNHP 2024, NatureServe 2026).
Ecology & Habitat

Habitat

Carex subnigricans grows at high elevations, often in wetlands, in moist, rocky, alpine to subalpine slopes and meadows, including boggy meadows in Utah, though generally in dry, rocky slopes in California (FNA 2002, Welsh et al. 2015, Jepson Flora Project 2026, OSU 2026).

Reproduction

This taxon fruits from June to September, also spreading vegetatively via rhizomes (FNA 2002, Jepson Flora Project 2026).
Terrestrial Habitats
Grassland/herbaceousAlpine
Other Nations (1)
United StatesN4
ProvinceRankNative
CaliforniaSNRYes
UtahS2Yes
WyomingS2Yes
OregonS1Yes
NevadaS2Yes
IdahoSNRYes
Threat Assessments
ThreatScopeSeverityTiming
2 - Agriculture & aquacultureUnknownUnknownHigh (continuing)
2.3 - Livestock farming & ranchingUnknownUnknownHigh (continuing)
4 - Transportation & service corridorsUnknownUnknownHigh (continuing)
4.1 - Roads & railroadsUnknownUnknownHigh (continuing)
6 - Human intrusions & disturbanceUnknownUnknownHigh (continuing)
6.1 - Recreational activitiesUnknownUnknownHigh (continuing)
8 - Invasive & other problematic species, genes & diseasesUnknownUnknownHigh (continuing)
8.1 - Invasive non-native/alien species/diseasesUnknownUnknownHigh (continuing)
8.1.2 - Named speciesUnknownUnknownHigh (continuing)
8.2 - Problematic native species/diseasesUnknownUnknownHigh (continuing)
8.2.2 - Named speciesUnknownUnknownHigh (continuing)
11 - Climate change & severe weatherUnknownUnknownHigh (continuing)
11.2 - DroughtsUnknownUnknownHigh (continuing)

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (2)
Nevada (2)
AreaForestAcres
Rose - EvansHumboldt-Toiyabe National Forest4,782
Rose - Whites CanyonHumboldt-Toiyabe National Forest2,568
References (11)
  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). 2026. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2026).
  3. iNaturalist. 2026. Online. Available: https://www.inaturalist.org (accessed 2026).
  4. Jepson Flora Project (eds.) 2026. Jepson eFlora. Online. Available: https://ucjeps.berkeley.edu/eflora/ (accessed 2026).
  5. 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.
  6. NatureServe. 2026. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  7. Oregon State University (OSU). 2026. Oregon Flora website. Oregon State University Herbarium at Oregon State University. Online. Available: https://oregonflora.org/ (accessed 2026).
  8. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  9. Southwest Environmental Information Network (SEINet). 2026. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2026).
  10. Utah Natural Heritage Program (UNHP). 2024. Element Subnational Ranking Form: <i>Carex subnigricans</i> in Biotics 5 database. NatureServe, Arlington, Virginia (accessed 21 April 2026).
  11. Welsh, S.L., N.D. Atwood, S. Goodrich, and L.C. Higgins. (Eds). 2015. A Utah flora, fifth edition, revised 2015. Monte L. Bean Life Science Museum, Provo, Utah. 987 pp.