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Asclepias viridiflora

Raf.

Green Milkweed

G5Secure Found in 22 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.156640
Element CodePDASC02260
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderGentianales
FamilyApocynaceae
GenusAsclepias
Other Common Names
Asclépiade à fleurs vertes (FR) green comet milkweed (EN) Green Comet Milkweed (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 Date2025-06-18
Change Date1985-04-05
Edition Date2025-06-19
Edition AuthorsWeldy, Troy W. (2004), rev. Johnson, J. (2025)
Threat ImpactUnknown
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Number of Occurrences> 300
Rank Reasons
Asclepias viridiflora is a wide-ranging perennial herb found across much of the eastern United States and Canada. However, it may be considered rare in some jurisdictions at the edges of its range. With a large range extent, more than 1200 occurrences, abundant habitat, broad habitat preferences, and no obvious intrinsic vulnerabilities, this species is considered secure.
Range Extent Comments
Asclepias viridiflora is found in the central and eastern United States, southern Canada, and northern Mexico, but is absent from the Maritime provinces and New England except Connecticut (FNA 2023). 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 1200 occurrences rangewide (GBIF 2025, iNaturalist 2025, RARECAT 2025, SEINet 2025).
Threat Impact Comments
Although threats are not widely documented, Asclepias viridiflora 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

Asclepias viridiflora grows on "slopes, ridges, bluffs, flats, canyons, arroyos, glades, fields, meadows, pastures, sandhills, dunes, pond edges, streamsides, playas, sandstone, limestone, gypsum, ser­pentine, dolomite, alluvium, silty, sandy, clay, rocky, and calcareous soils, prairies, desert grasslands, oak scrub, oak, oak-juniper, oak-hickory, pine-oak, and pine woodlands, forest openings and edges" (FNA 2023).
Terrestrial Habitats
Forest EdgeWoodland - HardwoodWoodland - ConiferWoodland - MixedShrubland/chaparralGrassland/herbaceousDesert
Palustrine Habitats
Riparian
Other Nations (2)
United StatesN5
ProvinceRankNative
IndianaS4Yes
NebraskaSNRYes
North CarolinaS4Yes
New YorkS2Yes
TennesseeSNRYes
VirginiaS5Yes
ColoradoS4Yes
OhioS4Yes
ConnecticutS1Yes
South DakotaSNRYes
MontanaS3Yes
KentuckyS4Yes
IowaS3Yes
LouisianaS4Yes
South CarolinaS3Yes
MissouriSNRYes
FloridaS1Yes
New MexicoSNRYes
TexasSNRYes
ArkansasSNRYes
MississippiSNRYes
IllinoisSNRYes
New JerseyS2Yes
OklahomaSNRYes
AlabamaSNRYes
WyomingS4Yes
DelawareS3Yes
MassachusettsSNRYes
North DakotaSNRYes
MarylandSNRYes
District of ColumbiaSNRYes
ArizonaS1Yes
MichiganSNRYes
West VirginiaS2Yes
GeorgiaS3Yes
KansasS5Yes
PennsylvaniaS4Yes
MinnesotaSNRYes
WisconsinSNRYes
CanadaN4
ProvinceRankNative
SaskatchewanS4Yes
ManitobaS3Yes
OntarioS2Yes
AlbertaS1Yes
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undeterminedUnknownUnknownUnknown

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)Yes
Roadless Areas (22)
Louisiana (1)
AreaForestAcres
Saline Bayou W & S River CorridorKisatchie National Forest5,355
Montana (3)
AreaForestAcres
HolterHelena National Forest1,965
Tenderfoot - Deep CreekLewis and Clark National Forest85,614
Tongue River BreaksCuster National Forest17,481
New Mexico (5)
AreaForestAcres
Alamo CanyonSanta Fe National Forest8,639
Black CanyonSanta Fe National Forest1,922
Juan de Gabaldon GrantSanta Fe National Forest8,023
Little TesuqueSanta Fe National Forest815
South Guadalupe MountainsLincoln National Forest20,930
North Dakota (10)
AreaForestAcres
Bullion ButteDakota Prairie Grasslands19,877
Collar / Bennett - CottonwoodDakota Prairie Grasslands19,697
DelamereDakota Prairie Grasslands5,087
DurlerDakota Prairie Grasslands12,464
Kinley PlateauDakota Prairie Grasslands16,900
Long X DivideDakota Prairie Grasslands10,099
Ponderosa PineDakota Prairie Grasslands7,471
SheyenneDakota Prairie Grasslands14,537
Twin ButtesDakota Prairie Grasslands13,492
WannaganDakota Prairie Grasslands6,026
Tennessee (1)
AreaForestAcres
Bald MountainCherokee National Forest11,743
West Virginia (1)
AreaForestAcres
North Mountain HopevilleMonongahela National Forest6,525
Wyoming (1)
AreaForestAcres
Little BighornBighorn National Forest133,949
References (6)
  1. Flora of North America Editorial Committee (FNA). 2023. Flora of North America north of Mexico. Vol. 14. Magnoliophyta: Gentianaceae to Hydroleaceae. Oxford Univ. Press, New York. xxiv + 505 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. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  6. Southwest Environmental Information Network (SEINet). 2025. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2025).