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Danthonia compressa

Austin ex Peck

Flattened Oatgrass

G5Secure Found in 1 roadless area NatureServe Explorer →
G5SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.149173
Element CodePMPOA20030
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderCyperales
FamilyPoaceae
GenusDanthonia
Other Common Names
Danthonie comprimée (FR) flattened oatgrass (EN) Mountain Oatgrass (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 Date2025-06-24
Change Date1984-04-24
Edition Date2025-06-24
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
Danthonia compressa is a perennial grass that is native to the eastern United States and southeastern Canada. With a large range extent, more than 300 occurrences, abundant habitat, and broad habitat preferences, this species is considered secure.
Range Extent Comments
Danthonia compressa is native to eastern North America from Wisconsin, United States, east to Newfoundland, Canada, and south to Arkansas and Georgia (FNA 2003). Range extent was estimated 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 300 occurrences rangewide (GBIF 2025, iNaturalist 2025, RARECAT 2025, SEINet 2025).
Threat Impact Comments
Although threats are not widely documented, Danthonia compressa is potentially threatened by development, road maintenance, invasive species, and other threats in some places. Notes in occurrence data suggest this species can colonize previously disturbed areas such as abandoned homesteads and railroads (NatureServe 2025). 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

Danthonia compressa grows in open and semi-shaded areas, including forest edges and openings, meadows, grassy balds, thin soils around rock outcrops, open woods, edges of shaded trails, old logging road beds, and old pastures, occasionally in wetland margins (FNA 2003, Native Plant Trust 2025, Weakley, A.S., and Southeastern Flora Team 2025).
Terrestrial Habitats
Forest EdgeWoodland - MixedSavannaGrassland/herbaceousOld field
Other Nations (2)
CanadaN5
ProvinceRankNative
QuebecS4Yes
OntarioS4Yes
Nova ScotiaS5Yes
New BrunswickS1Yes
Island of NewfoundlandSUYes
Prince Edward IslandS1Yes
United StatesN5
ProvinceRankNative
MichiganS3Yes
GeorgiaS3Yes
MassachusettsSNRYes
MarylandSNRYes
KentuckyS3Yes
MaineSNRYes
New JerseyS4Yes
South CarolinaS2Yes
ConnecticutSNRYes
IndianaS1Yes
VirginiaS5Yes
AlabamaSNRYes
North CarolinaS3Yes
New HampshireSNRYes
West VirginiaS5Yes
TennesseeSNRYes
District of ColumbiaSNRYes
PennsylvaniaS5Yes
OhioS4Yes
DelawareS2Yes
VermontS5Yes
New YorkS5Yes
Rhode IslandSNRYes
WisconsinSUYes
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undeterminedUnknownUnknownUnknown

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (1)
Maine (1)
AreaForestAcres
Caribou - Speckled ExtWhite Mountain National Forest5,988
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. Native Plant Trust. 2025. Go Botany website. Online. Available: https://gobotany.nativeplanttrust.org (accessed 2025).
  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).
  8. 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).