Epilobium hornemannii
Hornemann’s willowherb
Common Names
épilobe d’Hornemann
Hornemann’s willowweed
Hornemann’s willowherb
Synonyms
none
Subspecies
Epilobium hornemannii ssp. behringianum
Epilobium hornemannii ssp. hornemannii
Genus: Epilobium
Family: Onagraceae
Order: Myrtales
taxonomic heirarchy
Duration – Growth Habit
Perennial – Forb/herb
Identification and Information
Epilobium hornemannii, commonly known as Hornemann’s willowherb, is a small perennial herb belonging to the Onagraceae (primrose) family. It grows from short, leafy stolons (runners) in clumps with erect stems up to 45 cm tall. The leaves are often opposite and lanceolate proximal to the inflorescence while alternate and ovate or egg-shaped distally. Leaf petioles are longer distally from the inflorescence, 3-9 mm long. Leaves are also simple, sparsely denticulate, sometimes with short, stiff hairs.
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The inflorescence is an open, glandular, terminal raceme with erect or nodding flowers. The flowers are rose to pink, sometimes white, with 0.7-2.4 mm deep notches at the tip. The notched petals are 3-9 mm long, while the sepals are shorter, 2-4.5 mm long, and sometimes red-tipped. Flowers are perfect, with both male and female parts. Stamen filaments are cream or light pink with yellow anthers, and the styles are white or cream, 2-8mm long. The fruit is a 4-6.5 cm long linear capsule, and the seeds have tufts of white hair that help with dispersal by wind.
Two recognized subspecies are found in overlapping areas: E. hornemannii subsp. hornemannii with shorter petioles and sepals and E. hornemannii subs. behringianum, which has more leathery leaves and longer petioles and sepals. Subspecies hornemannii is more common at higher elevations, and subspecies hornemannii is more common at lower and maritime elevations. However, they may both be present at a wide range of elevations.
There are approximately 20 species of Epilobium in Alaska, many of which closely resemble each other and can be challenging to differentiate based on morphology alone.
Uses
For information only (typically historical) – I take no responsibility for adverse effects from the use of any plant.
No traditional, medicinal, or culinary uses were found.
Distribution and Habitat
Map data from the Global Biodiversity Information Facility (GBIF), NatureServe Explorer, and Kew
Epilobium hornemannii is common in western and northeastern North America, eastern Siberia, Greenland, Iceland, and Scandinavia.
It’s habitat includes meadows and tundra, alpine or montane zones, rocky slopes, meadows, floodplains, and river banks.
Classification
| Rank | Scientific Name (Common Name) |
|---|---|
| Kingdom | Plantae (plantes, Planta, Vegetal, plants) |
| Subkingdom | Viridiplantae (green plants)) |
| Infrakingdom | Streptophyta (land plants) |
| Superdivision | Embryophyta |
| Division | Tracheophyta (vascular plants, tracheophytes) |
| Subdivision | Spermatophytina (spermatophytes, seed plants, phanérogames) |
| Class | Magnoliopsida |
| Superorder | Rosanae |
| Order | Myrtales |
| Family | Onagraceae (evening primroses, onagres) |
| Genus | Epilobium L. (willow weed, willowweed, willowherb) |
| Species | Epilobium hornemannii Rchb. (Hornemann’s willowweed, Hornemann’s willowherb) |
| Direct Children: | |
| Subspecies | Epilobium hornemannii ssp. behringianum (Hausskn.) Hoch & P.H. Raven (Hornemann’s willowherb) |
| Subspecies | Epilobium hornemannii ssp. hornemannii Rchb. (Hornemann’s willowherb) |
References and Further Reading
Guidebook
Pratt, V. E. (1989). Field Guide to Alaskan Wildflowers: Commonly Seen Along Highways and Byways (p. 15 genus only). Alaskakrafts, inc.
Brandenburg, D. M. 2010. National Wildlife Federation Field Guide to Wildflowers of North America. Sterling Publishing. (p. 360-361 genus only)
Johnson, D., Kershaw, L., & MacKinnon, A. (2020). Plants of the Western Forest: Alaska to Minnesota Boreal and Aspen Parkland (3rd ed., p. 150 genus only). Partners Publishing. ISBN 978-1772130591.
Classification and Taxonomy
Integrated Taxonomic Information System (ITIS). (n.d.). Epilobium hornemannii. Retrieved May 5, 2024, from https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=27306
Canadensys. (n.d.). Epilobium hornemannii. Retrieved May 5, 2024, from https://data.canadensys.net/vascan/taxon/6778
Catalogue of Life. (n.d.). Epilobium hornemannii. Retrieved May 5, 2024, from https://www.catalogueoflife.org/data/taxon/6G4K4
USDA PLANTS Database. (n.d.). Epilobium hornemannii. Retrieved May 5, 2024, from https://plants.usda.gov/home/plantProfile?symbol=EPHO
Uses
no references
Map and Distribution
Global Biodiversity Information Facility (GBIF). (n.d.). Epilobium hornemannii. Retrieved May 5, 2024, from https://www.gbif.org/species/3189153
Plants of the World Online. (n.d.). Epilobium hornemannii. Retrieved May 5, 2024, from https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:611932-1
NatureServe Explorer. (n.d.). Epilobium hornemannii. Retrieved May 5, 2024, from https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.128233/Epilobium_hornemannii
Description and Information
Flora of North America. (n.d.). Epilobium hornemannii. Retrieved May 5, 2024, from http://floranorthamerica.org/Epilobium_hornemannii
Hultén, E. (1968). Flora of Alaska and Neighboring Territories: A Manual of the Vascular Plants (1st ed.) (pg. 692). Stanford University Press.
Alaska Center for Conservation Science – UAF. (n.d.). Epilobium hornemannii. Retrieved May 5, 2024, from https://ecologicalatlas.uaf.edu/index.php/browse-plant-species/atlas-page/?nps_id=805
E-Flora BC: Electronic Atlas of the Plants of British Columbia. (n.d.). Epilobium hornemannii. Retrieved May 5, 2024, from https://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Epilobium%20hornemannii&redblue=Both&lifeform=7
Canadian Museum of Nature. (n.d.). Epilobium hornemannii. Retrieved May 5, 2024, from https://nature.ca/aaflora/data/www/onep.htm
