Epilobium lactiflorum

Hausskn.

White-flower Willowherb

G5Secure Found in 1 roadless area NatureServe Explorer →
G5SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.150394
Element CodePDONA060D0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderMyrtales
FamilyOnagraceae
GenusEpilobium
Other Common Names
Épilobe à fleurs blanches (FR) milkflower willowherb (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 Date2025-08-11
Change Date1988-08-04
Edition Date2025-08-11
Edition AuthorsN. Ventrella (2025)
Threat ImpactUnknown
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Number of Occurrences> 300
Rank Reasons
Epilobium lactiflorum is a perennial forb occurring on cliffs, stream banks, crevices, roadsides, burned-over woodlands, forests, and alpine meadows of subarctic to subalpine regions of North America, Greenland, and Eurasia. There are over 1,000 estimated occurrences of this species rangewide, which are potentially threatened by succession, climate change, altered hydrology, recreation, invasive species, and likely other threats in some places. Little is known about trends, but with a large range extent and large number of occurrences, Epilobium lactiflorum is considered secure.
Range Extent Comments
Epilobium lactiflorum occurs in subarctic to subalpine regions of North America, Greenland, and Eurasia (POWO 2025). In North America, its western range is from Yukon and the Northwest Territories, Canada, and Alaska south to New Mexico and California in the United States (FNA 2021). The eastern portion of its North American range is from Ontario east to Newfoundland and Labrador, Canada, south to Maine and New Hampshire (where considered historical) in the United States (FNA 2021, Native Plant Trust 2025). Range extent was estimated to be over 37 million square kilometers using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1994 and 2025 (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 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 more than 1,000 occurrences rangewide (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Threat Impact Comments
Threats to Epilobium lactiflorum are not well documented, but potentially include succession, climate change, altered hydrology, recreation, invasive species, and likely 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.
Ecology & Habitat

Habitat

Epilobium lactiflorum occurs on cliffs, alpine gullies, "montane stream banks, moist crevices and ledges, gravelly roadsides, burned-over woodlands, sandy moraines, subalpine forests, [and] alpine meadows" from 50-3800 m in elevation (FNA 2021, Native Plant Trust 2025).

Reproduction

Epilobium lactiflorum produces flowers from June through September (FNA 2021).
Terrestrial Habitats
Forest/WoodlandForest EdgeGrassland/herbaceousAlpineCliff
Palustrine Habitats
FORESTED WETLANDRiparian
Other Nations (2)
CanadaN5
ProvinceRankNative
LabradorS3Yes
OntarioS1Yes
Northwest TerritoriesS3Yes
Nova ScotiaS1Yes
QuebecS3Yes
Yukon TerritoryS3Yes
British ColumbiaS5Yes
AlbertaS3Yes
Island of NewfoundlandS3Yes
United StatesN5
ProvinceRankNative
MontanaSNRYes
AlaskaSNRYes
ArizonaS1Yes
WashingtonSNRYes
IdahoSNRYes
CaliforniaSNRYes
MaineSHYes
New MexicoSNRYes
UtahSNRYes
NevadaS1Yes
ColoradoS3Yes
WyomingS4Yes
New HampshireSHYes
OregonSNRYes
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undetermined

Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (1)
Washington (1)
AreaForestAcres
Mt. Baker NorthMt Baker-Snoqualmie National Forest16,873
References (9)
  1. Flora of North America Editorial Committee (FNA). 2021. Flora of North America north of Mexico. Vol. 10. Magnoliophyta: Proteaceae to Elaeagnaceae. Oxford Univ. Press, New York. xxiv + 456 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. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  7. Plants of the World Online (POWO). 2025. Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Online. Available: https://powo.science.kew.org/ (accessed 2025).
  8. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  9. Southwest Environmental Information Network (SEINet). 2025. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2025).