Elymus macgregorii

R.E. Brooks & J. Campbell

MacGregor's Wild Rye

G5Secure Found in 1 roadless area NatureServe Explorer →
G5SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.791665
Element CodePMPOA2H1V0
Record TypeSPECIES
ClassificationSpecies
Classification StatusProvisional
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderCyperales
FamilyPoaceae
GenusElymus
Other Common Names
Early Wildrye (EN) early wildrye (EN) Élyme de MacGregor (FR) MacGregor's Wildrye (EN)
Concept Reference
Campbell, J.J.N. 2000. Notes on North American Elymus species (Poaceae) with paired spikelets: I. E. macgregorii sp. nov. and E. glaucus ssp. mackenzii comb. nov. Journal of the Kentucky Academy of Science 61: 88-98.
Taxonomic Comments
Elymus macgregorii was described in Campbell (2000) and also recognized by Flora of North America Editorial Committee (2007). Per Weakley (2015) Elymus macgregorii is narrower than E. virginicus var. virginicus of Kartesz (1994, 1999).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-01-29
Change Date2017-07-10
Edition Date2025-01-29
Edition AuthorsSoteropoulos (2025)
Threat ImpactUnknown
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Number of Occurrences81 to >300
Rank Reasons
Elymus macgregorii is a wide-ranging perennial graminoid in alluvial forests occurring in eastern and central North America from Ontario, Canada south into the United States from Maine west to South Dakota south to Florida and Texas. It is potentially threatened by development, rights-of-way maintenance, logging, invasive species, and erosion. Little is known about trends, but with a large range extent and large number of occurrences, abundant habitat, broad habitat preferences, and no obvious intrinsic vulnerabilities, this species is considered secure.
Range Extent Comments
Elymus macgregorii occurs in eastern and central North America from Ontario, Canada south into the United States from Maine west to South Dakota south to Florida and Texas (FNA 2007). Range extent was estimated to be over 2.7 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, 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 over 240 occurrences rangewide (GBIF 2025, iNaturalist 2025, NatureServe 2025, SEINet 2025).
Threat Impact Comments
Although threats are not widely documented, this species is potentially threatened by development, rights-of-way maintenance, logging, invasive species, erosion, and other threats in some places. However, their overall impact is likely negligible given the species' broad range, large number of occurrences, and no obvious intrinsic vulnerabilities.
Ecology & Habitat

Habitat

Elymus macgregorii grows in "moist, deep, alluvial or residual, calcareous or other base-rich soils in woods and thickets" (FNA 2007).
Terrestrial Habitats
Forest/WoodlandForest - HardwoodForest - Mixed
Palustrine Habitats
FORESTED WETLANDRiparian
Other Nations (2)
United StatesN5
ProvinceRankNative
PennsylvaniaSNRYes
MaineS2Yes
AlabamaSNRYes
IllinoisSNRYes
MissouriSNRYes
NebraskaSNRYes
Rhode IslandSHYes
TennesseeSNRYes
District of ColumbiaSNRYes
South DakotaSNRYes
MississippiSNRYes
ConnecticutSNRYes
GeorgiaS1Yes
KentuckyS5Yes
North DakotaSNRYes
VirginiaSNRYes
DelawareSUYes
LouisianaSNRYes
OhioSNRYes
MassachusettsS2Yes
KansasS3Yes
FloridaSNRYes
WisconsinSNRYes
IndianaSNRYes
VermontSHYes
ArkansasSNRYes
MarylandSNRYes
OklahomaSNRYes
New YorkSNRYes
TexasSNRYes
North CarolinaSNRYes
West VirginiaSNRYes
New JerseySNRYes
IowaSNRYes
CanadaN1
ProvinceRankNative
OntarioS1Yes
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undetermined

Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (1)
Illinois (1)
AreaForestAcres
Ripple HollowShawnee National Forest3,788
References (7)
  1. Campbell, J.J.N. 2000. Notes on North American <i>Elymus </i>species (Poaceae) with paired spikelets: I. <i>E. macgregorii </i>sp. nov. and <i>E. glaucus </i>ssp. <i>mackenzii </i>comb. nov. Journal of the Kentucky Academy of Science 61: 88-98.
  2. Flora of North America Editorial Committee (FNA). 2007a. Flora of North America north of Mexico. Vol. 24. Magnoliophyta: Commelinidae (in part): Poaceae, part 1. Oxford Univ. Press, New York. xxviii + 911 pp.
  3. Global Biodiversity Information Facility (GBIF). 2025. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2025).
  4. Haines, A. 2011. Flora Novae Angliae: a manual for the identification of native and naturalized higher vascular plants of New England. Yale University Press, New Haven, CT. 973 pp.
  5. iNaturalist. 2025. Online. Available: https://www.inaturalist.org (accessed 2025).
  6. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  7. Southwest Environmental Information Network (SEINet). 2025. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2025).