(Chamaenerion angustifolium)

Photo by Bill Reynolds

Fireweed, also called great willowherb in Canada and rosebay willowherb in Europe, is a common and very widespread plant native to North America, Europe, and Asia. There are two subspecies of fireweed, both of which occur in Minnesota.

Fireweed is a pioneer species, one of the first plants to colonize a disturbed area. It is well-adapted to grow in areas that have experienced a disturbance, such as wildfires. Its seeds are able to quickly germinate in exposed soil. It prefers well-drained soils and full sun, but it can also grow in partial shade. It is tolerant of a wide range of soil conditions, from acidic to alkaline, and can grow in nutrient-poor soils.


Fireweed is found at woodland edges, at the edges of sedge meadows, in bogs, and in ravines. It is also found in disturbed areas where trees and shrubs have been removed, including in burned or clear-cut forests and along roadsides.

The flowers in the inflorescence mature from the bottom up. The stamens are erect at first and the style is sharply bent backward. After one or two days, the stamens bend backward, and the style straightens and opens up. Bees visiting the plant start at the bottom of the inflorescence and work their way to the top. When there is no more nectar to be collected, they proceed to the next inflorescence, again starting at the bottom. This system of male flower parts developing before female parts is known as protandry. It ensures that the plant will not self-pollinate.


Fireweed is an erect, perennial, 8 to 78 tall forb that rises usually on a single aerial stem from a rhizome-like underground stem and fibrous roots. It often forms large colonies.

The stem is smooth, hairless, and reddish-brown.

The leaves are alternate and narrowly lance-shaped. The species epithet angustifolium means “narrow-leaved”. The margins are untoothed.

The inflorescence is a dense, cylinder-shaped, spire-like cluster of many flowers at the top of the stem.

The flowers are showy and bright pink to purple. Each flower has 4 petals and 4 sepals, and they are arranged in a radial symmetry.

The fruit is a long, narrow seed pod filled with tiny seeds that are dispersed by wind.


Distribution Map



2, 3, 4, 5, 7, 24, 28, 29, 30.

  Kingdom Plantae (green algae and land plants)  
  Subkingdom Viridiplantae (green plants)  
  Infrakingdom Streptophyta (land plants and green algae)  
  Superdivision Embryophyta (land plants)  
  Division Tracheophyta (vascular plants)  
  Subdivision Spermatophytina (seed plants)  
  Class Magnoliopsida (flowering plants)  
  Superorder Rosanae  
  Order Myrtales (myrtles, evening primroses, and allies)  


Onagraceae (evening primrose)  
  Subfamily Onagroideae  
  Tribe Epilobieae  


Chamaenerion (fireweeds)  

Species in the genus Chamaenerion were originaly placed in the genus Epilobium. A group of several species was later separated from Epilobium as the new genus Chamaenerion. Recently it was determined that the name Chamaenerion was invalid “because it was derived from pre-Linnean sources and is synonymous with Epilobium,” and the genus name was shortened to Chamerion. A more recent clarification of the internationational Code of Botanical Nomenclature (ICBN), now the International Code of Nomenclature (ICN), “correctly argued that the name of the segregated genus should be Chamaenerion.”

Today (2023) there is little agreement as to the proper placement of the group.

ITIS and USDA PLANTS use the name Chamerion angustifolium.

NCBI, GRIN, GBIF, BONAP, Tropicos, Flora of North America, and iNaturalist use the name Chamaenerion angustifolium.

Plants of the World Online and World Flora Online use the name Epilobium angustifolium.


Subordinate Taxa


fireweed (Chamaenerion angustifolium ssp. angustifolium)

fireweed (Chamaenerion angustifolium ssp. circumvagum)




Chamaenerion angustifolium

Epilobium angustifolium


Common Names




great willow-herb (Canada)

great willowherb (Canada)

rosebay willowherb (Europe)










Visitor Photos

Share your photo of this plant.

  This button not working for you?
Simply email us at
Attach one or more photos and, if you like, a caption.

Bill Reynolds


My honeybees worked this late summer plant.

    fireweed   fireweed  



  Epilobium angustifolium
Susanne Wiik
  Epilobium angustifolium  

Geitrams fireweed


Copyright DianesDigitals

Andree Reno Sanborn

Epilobium angustifolium

  Chamerion angustifolium (Fireweed)
Allen Chartier
  Chamerion angustifolium (Fireweed)  



Visitor Videos

Share your video of this plant.

  This button not working for you?
Simply email us at
Attach a video, a YouTube link, or a cloud storage link.


Other Videos
  Fireweed (Epilobium Angustifolium) / Great Willow-herb - 2013-07-13

Published on Aug 2, 2013

Published on Aug 2, 2013 Epilobium angustifolium, commonly known as Fireweed (mainly in North America), Great Willow-herb (some parts of Canada),[1] or Rosebay Willowherb (mainly in Britain), is a perennial herbaceous plant in the willowherb family Onagraceae.

Het (knikkend) wilgenroosje (Chamerion angustifolium (L.) Holub, soms ook Chamaenerion angustifolium (L.) Scop., basioniem: Epilobium angustifolium L.) is een overblijvende, kruidachtige plant uit de teunisbloemfamilie (Onagraceae).

50.77636 5.82428

  Willowherb - Sigurskúfur - Dúnurt - Villijurtir - Sumarblóm
Hellen Linda Drake

Published on Sep 6, 2013

Willowherb - Epilobium angustifolium - Chamerion angustifolium - Rosebay Willowherb - Fireweed - Dúnurt - Sigurskúfur

Sigurskúfur (fræðiheiti: Epilobium angustifolium) er fjölær jurt af eyrarrósarætt. Hann tilheyrir dúnurtum og getur orðið allt að 70 cm á hæð. Sigurskúfur ber rauð blóm og er algengur um allt norðurhvel jarðar. Blómin eru mörg í klasa upp eftir plöntunni. Þau eru um 2 cm í þvermál. Krónublöðin eru rauð en bikarblöðin dökkrauð. Í hverju blómi er 8 fræflar. Frævan er löng og hærð. Blöðin standa gagnstætt á stilknum. Þau eru 4 til 12 cm á lengd og 1 til 2 cm á breidd. Þau eru lensulaga, heilrennd eða með litlar tennur og hárlaus. Sigurskúfur er áburðarfrekur og vex því gjarnan í kringum bæi - oft í þéttum breiðum. Í skóglendi og klettum vex hann villtur - blómstrar seint. Í gras- eða mólendi er hann stundum dvergvaxinn og blómstrar ekki vegna næringarskorts. Þá myndar hann 10 til 20 cm langa blaðsprota. :

Rosebay Willowherb is an adaptable friend. Most parts of the plant are edible, medicinal and have other fantastic properties. See more:

This herb is often abundant in wet calcareous to slightly acidic soils in open fields, pastures, and particularly burned-over lands; the name Fireweed derives from the species' abundance as a coloniser on burnt sites after forest fires. Its tendency to quickly colonize open areas with little competition, such as sites of forest fires and forest clearings, makes it a clear example of a pioneer species. The reddish-brown linear seed capsule splits from the apex. It bears many minute brown seeds, about 300 to 400 per capsule and 80,000 per plant. :

Willowherbs are typically very quick to carpet large swathes of ground and may become key or dominant species of local ecosystems. In and around the United Kingdom, for example, rosebay willowherb (E. angustifolium) is widely found in mesotrophic grassland dominated by false oat-grass (Arrhenatherum elatius), cock's-foot (Dactylis glomerata), and red fescue (Festuca rubra), while great willowherb (Epilobium hirsutum) is found in mesotrophic grassland with stinging nettle (Urtica dioica). These two willowherb species are also seen to dominate open habitat early in ecological succession, to the virtual exclusion of other plant life. Broad-leaved willowherb (Epilobium montanum) is found characteristically, though not abundantly, in the mesotrophic grasslands with meadowsweet (Filipendula ulmaria) and sometimes the uncommon Greek valerian (Polemonium caeruleum), which are peculiar to the Pennines. Most willowherbs will not tolerate shade trees and thus are limited to more recently disturbed patches, yielding to other plants over time. Consequently, though the genus contains many pioneer plants, rather few of them are invasive weeds of major importance. :

Rosebay willowherb is tolerant of acid and alkaline soils but does not grow in soils with poor mineral nutrition. Rosebay willowherb tolerates shade and a broad range of climatic conditions. It is suspected by some botanists that the sudden spread of rosebay willowherb was due to the introduction of the North American form that has 72 chromosomes while the native form has 36. Considerable intraspecific variation has been observed in rosebay willowherb in North America where it is eaten by deer and range cattle. It was also used as a food plant by the native indians. The nectar is important for hive bees in certain localities. Seeds remain viable for 18 months but do not form a persistent seedbank. Seeds lose viability after 18 months dry storage at room temperature but persist for more than 2 years stored dry at 5°C. :

Á íslandi finnst fylgjandi jurtir af dúnurtum:
Lindadúnurt (Epilobium alsinifolium)
Fjalladúnurt (Epilobium anagallidifolium)
Sigurskúfur (Chamerion angustifolium)
Vætudúnurt (Epilobium ciliatum)
Klappadúnurt (Epilobium collinum)
Heiðadúnurt (Epilobium hornemannii)
Ljósadúnurt (Epilobium lactiflorum)
Eyrarrós (Chamerion latifolium)
Mýradúnurt (Epilobium palustre)

Sigurskúfur er tiltölulega ný r landnemi á Íslandi :

Unfortunately handheld, with such a macro and a minuscule depth of field the video is shaky and not always on focus.

  sitting in the fire weed.

Uploaded on Jul 19, 2010

stopped to watch the bees. whole place was buzzing but it doesn't come out on camera. my dog was mumphing. :-)))




Visitor Sightings

Report a sighting of this plant.

  This button not working for you?
Simply email us at
Be sure to include a location.
  Bill Reynolds

Location: St. Louis Co.

My honeybees worked this late summer plant.







Last Updated:

© All rights reserved.

About Us

Privacy Policy

Contact Us