Reichenb.
Identity
Unique IDELEMENT_GLOBAL.2.128233
Element CodePDONA060C0
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 NamesÉpilobe de Hornemann (FR) Hornemann's willowherb (EN)
Concept ReferenceKartesz, 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 Date1984-04-24
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 ReasonsEpilobium hornemannii is a perennial forb occurring in moist meadows, willow swales, coastal places, stream banks, mossy crevices, and stabilized scree slopes of North America, western Eurasia, Japan, and the Russian Far East. In North America, it occurs throughout most of Canada, and Alaska south through California, west to New Mexico, north to North Dakota in the western United States, and Maine to New York in the eastern United States. There are over 2,000 estimated occurrences of this species, which are threatened by 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 hornemannii is considered secure.
Range Extent CommentsEpilobium hornemannii occurs "widely in montane and boreal regions in North America and western Eurasia, and also in Japan and the Russian Far East" (FNA 2021). In North America, it occurs throughout most of Canada, and Alaska south through California, west to New Mexico, north to North Dakota in the western United States, and Maine to New York in the eastern United States. Epilobium hornemannii ssp. hornemannii is found throughout the range of the species; Epilobium hornemannii ssp. behringianum is a coastal variant, occurring in maritime areas of British Columbia, including Haida Gwaii, Pacific coastal Alaska, and along the northwestern Pacific Coast of Russia. Range extent was estimated to be over 6 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 CommentsBy 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 2,000 occurrences rangewide (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Threat Impact CommentsThreats to Epilobium hornemannii are not well documented but include altered hydrology, recreation, invasive species, and likely other threats in some places (NatureServe 2025). There is insufficient data, including anecdotal accounts, to understand the scope and severity of threats for this taxon.