Roadless Areas
Home/Species/ Old Witch Panicgrass

Panicum capillare

L.

Old Witch Panicgrass

G5Secure Found in 14 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.147313
Element CodePMPOA4K0D0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderCyperales
FamilyPoaceae
GenusPanicum
Synonyms
Panicum capillare ssp. capillare
Other Common Names
Common Panicgrass (EN) Panic capillaire (FR) witchgrass (EN) Witchgrass (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 Panicum capillare, excluding P. hillmanii as a distinct species, as recognized in Kartesz (1994, 1999). Freckmann and Lelong in FNA (2003, vol. 25) recognize P. hillmanii as P. capillare ssp. hillmanii.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-07-02
Change Date1988-04-28
Edition Date2025-07-02
Edition AuthorsJohnson, J. (2025)
Threat ImpactUnknown
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Number of Occurrences> 300
Rank Reasons
Panicum capillare is an annual grass that is native across southern Canada, the continental United States, and Mexico, Burmuda, the Virgin Islands, and sporadically in South America, and is introduced to many areas around the world. With a broad distribution, high tolerance for disturbance, and no obvious threats, this species is considered secure.
Range Extent Comments
Panicum capillare is widespread in North America, from southern Canada, through the continental United States into Mexico, Bermuda, the Virgin Islands, and sporadically in South America (FNA 2003, Weakley and the Southeastern Flora Team 2025). It is also widely naturalized in Europe, Asia, Australia, and New Zealand (GBIF 2025, POWO 2025). The native range extent was estimated to be greater than 12 million square kilometers using herbarium specimens and photo-based observations documented between 1994 and 2025 (GBIF 2025, iNaturalist 2025, RARECAT 2025, SEINet 2025).
Occurrences Comments
By applying a 1 km separation distance to herbarium records and photo-based observations documented between 1994 and 2025, there are estimated to be more than 1500 occurrences across this species' native range (GBIF 2025, iNaturalist 2025, RARECAT 2025, SEINet 2025).
Threat Impact Comments
Although threats are not widely documented, Panicum capillare is potentially threatened by development, road maintenance, invasive species, and other threats in some places. However, their overall impact is likely negligible given the species' broad range, large number of occurrences, tolerance of light disturbance, and affinity for typically abundant habitats, as well as no obvious intrinsic vulnerabilities.
Ecology & Habitat

Habitat

"Panicum capillare grows in open areas, particularly in disturbed sites such as fields, pastures, roadsides, waste places, ditches, sand, and rock crevices, etc." (FNA 2003).
Terrestrial Habitats
Grassland/herbaceousOld fieldCropland/hedgerowSuburban/orchard
Other Nations (2)
CanadaN5
ProvinceRankNative
British ColumbiaS5Yes
New BrunswickSNRYes
Nova ScotiaSNANo
QuebecS4Yes
Prince Edward IslandSNANo
SaskatchewanS4Yes
OntarioSNRYes
AlbertaSUYes
ManitobaS4Yes
United StatesN5
ProvinceRankNative
MinnesotaSNRYes
New HampshireSNRYes
LouisianaSNRYes
IllinoisS5Yes
IndianaS5Yes
MaineSNRYes
ArizonaSNRYes
IdahoSNRYes
WisconsinSNRYes
VermontSNRYes
TexasSNRYes
WyomingS4Yes
OklahomaSNRYes
New YorkS5Yes
PennsylvaniaS5Yes
New JerseyS5Yes
VirginiaS5Yes
NebraskaSNRYes
District of ColumbiaSNRYes
GeorgiaSNRYes
MassachusettsSNRYes
ConnecticutS4Yes
MississippiSNRYes
UtahSNRYes
FloridaSNRYes
South CarolinaSNRYes
North CarolinaS4Yes
AlabamaSNRYes
North DakotaSNRYes
NevadaS3Yes
New MexicoSNRYes
MissouriSNRYes
MontanaS4Yes
West VirginiaS5Yes
OregonSNRYes
MarylandSNRYes
ArkansasSNRYes
IowaS5Yes
CaliforniaSNRYes
ColoradoS4Yes
OhioSNRYes
DelawareS5Yes
Rhode IslandSNRYes
WashingtonSNRYes
KansasS5Yes
MichiganSNRYes
South DakotaSNRYes
TennesseeSNRYes
KentuckyS5Yes
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undeterminedUnknownUnknownUnknown

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Plant Characteristics
DurationANNUAL
Economic Value (Genus)No
Roadless Areas (14)
Arizona (1)
AreaForestAcres
BoulderTonto National Forest40,359
California (1)
AreaForestAcres
San Gabriel AddAngeles National Forest2,527
Idaho (2)
AreaForestAcres
Bighorn - WeitasNez Perce-Clearwater National Forest254,845
North Lochsa SlopeNez Perce-Clearwater National Forest117,662
New Mexico (1)
AreaForestAcres
RendijaSanta Fe National Forest2,176
North Dakota (1)
AreaForestAcres
Long X DivideDakota Prairie Grasslands10,099
Oregon (3)
AreaForestAcres
Flag CreekMalheur National Forest7,716
Hurricane CreekWallowa-Whitman National Forest1,606
North Fork MalheurMalheur National Forest18,069
Utah (1)
AreaForestAcres
WellsvilleWasatch-Cache National Forest1,717
Washington (3)
AreaForestAcres
Abercrombie - HooknoseColville National Forest33,862
Nason RidgeWenatchee National Forest19,329
TaneumWenatchee National Forest26,140
Wyoming (1)
AreaForestAcres
Middle ForkShoshone National Forest51,772
References (8)
  1. Flora of North America Editorial Committee (FNA). 2003a. Flora of North America north of Mexico. Vol. 25. Magnoliophyta: Commelinidae (in part): Poaceae, part 2. Oxford Univ. Press, New York. xxv + 781 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. 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. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  7. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  8. Southwest Environmental Information Network (SEINet). 2025. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2025).