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Carex willdenowii

Schkuhr ex Willd.

Willdenow's Sedge

G5Secure (G5?) Found in 2 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.142413
Element CodePMCYP03ET2
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderCyperales
FamilyCyperaceae
GenusCarex
Synonyms
Carex willdenowii var. willdenowii
Other Common Names
Carex de Willdenow (FR) Willdenow's 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.
Taxonomic Comments
This record is for the narrow treatment of Carex willdenowii, excluding C. willdenowii var. megarrhyncha F.J. Herm. which was found by Naczi et al. (1998) to be a mix of what they establish are two distinct species: C. supernata Naczi, Reznicek, & B.A. Ford and C. basiantha (previously published by Steudel in 1855). Crins et al. in FNA (2002, vol. 23), Weakley et al. (2025), and Kartesz (1999) recognize three species, following Naczi et al. (1998). Kartesz (1994) recognized a broader treatment of C. willdenowii with varieties megarrhyncha and willdenowii.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2024-07-08
Change Date2024-07-08
Edition Date2024-07-08
Edition AuthorsKaranosky, M. (2000), rev. Soteropoulos (2024)
Threat ImpactUnknown
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences81 to >300
Rank Reasons
Carex willdenowii is a wide-ranging perennial sedge in dry to mesic upland oak forests occurring in eastern North America from Ontario, Canada and Vermont, United States south to Florida and west to Texas. Threats include development, rights-of-way maintenance, logging, recreational activities, deer browsing, and invasive species. Little is known about trends, but with a large range extent and large number of occurrences, this species is considered secure.
Range Extent Comments
Carex willdenowii occurs in eastern North America from Ontario, Canada and Vermont, United States south to Florida and west to Texas (FNA 2002, Weakley and the Southeastern Flora Team 2024). Range extent was estimated to be approximately 1.9 million square kilometers using herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1993 and 2024 (GBIF 2024, iNaturalist 2024, NatureServe 2024, SEINet 2024).
Occurrences Comments
By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1993 and 2024, it is estimated that there are over 230 occurrences rangewide (GBIF 2024, iNaturalist 2024, NatureServe 2024, SEINet 2024).
Threat Impact Comments
Although threats are not widely documented, this species is potentially threatened by development, rights-of-way maintenance, logging, recreational activities, deer browsing, invasive species, and other threats in some places.
Ecology & Habitat

Habitat

Carex willdenowii grows in "acidic, dry mesic, open, oak-dominated woodlands, often on ridges and slopes" (FNA 2002).
Terrestrial Habitats
Forest/WoodlandForest - HardwoodForest - Mixed
Other Nations (2)
CanadaN1
ProvinceRankNative
OntarioS1Yes
United StatesN5
ProvinceRankNative
West VirginiaS5Yes
MassachusettsS1Yes
VermontSHYes
DelawareS1Yes
MissouriS1Yes
District of ColumbiaSNRYes
ConnecticutS1Yes
IllinoisS2Yes
IndianaS4Yes
North CarolinaS2Yes
MarylandSNRYes
AlabamaSNRYes
New JerseyS2Yes
South CarolinaS1Yes
VirginiaS5Yes
KentuckyS4Yes
OhioSNRYes
ArkansasS1Yes
TennesseeSNRYes
GeorgiaSNRYes
PennsylvaniaSNRYes
New YorkS4Yes
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undetermined———

—

Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (2)
Illinois (2)
AreaForestAcres
Bay CreekShawnee National Forest120
Ripple HollowShawnee National Forest3,788
References (10)
  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). 2024. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2024).
  3. iNaturalist. 2024. Online. Available: https://www.inaturalist.org (accessed 2024).
  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. Kartesz, J.T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: Kartesz, J.T., and C.A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, N.C.
  6. Naczi, R. F. C., A. A. Reznicek, and B. A. Ford. 1998. Morphological, geographical, and ecological differentiation in the <i>Carex willdenowii</i> complex (Cyperaceae). American Journal of Botany 85(3):434-447.
  7. NatureServe. 2024. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  8. Southwest Environmental Information Network (SEINet). 2024. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2024).
  9. Weakley, A.S., and Southeastern Flora Team. 2024. Flora of the southeastern United States. Edition of March 4, 2024. University of North Carolina Herbarium (NCU), North Carolina Botanical Garden, University of North Carolina, Chapel Hill. 2203 pp.
  10. Weakley, A.S., and Southeastern Flora Team. 2025. Flora of the southeastern United States Web App. Edition of February 18, 2025. University of North Carolina Herbarium (NCU), North Carolina Botanical Garden, University of North Carolina, Chapel Hill. Online. Available: https://fsus.ncbg.unc.edu (accessed 2025).