Epilobium anagallidifoliumLam.

pimpernel willowherb

WFO wfo-0000668738 Accepted WFO 2026-06 8 photographs CC0 / CC BY / CC BY-SA

Plate 1 figs. a–h · 8 separate observations

Epilobium anagallidifolium, photographed by Trevor Van Loon
fig. a Trevor Van Loon, CC BY 4.0 / 2021-08-01 / obs. 151741270

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

Native range 66 botanical countries

Regions where Epilobium anagallidifolium is native: Altay, Buryatiya, Irkutsk, Japan, Kamchatka, Krasnoyarsk, Kuril Is., Magadan, Mongolia, North Caucasus, Transcaucasus, Türkiye, Tuva, West Siberia, Xinjiang, Yakutiya, East Himalaya, West Himalaya, Albania, Austria, Bulgaria, Central European Russia, Corse, Czechia-Slovakia, Finland, Føroyar, France, Germany, Great Britain, Greece, Iceland, Italy, North European Russia, Norway, NW. Balkan Pen., Poland, Portugal, Romania, Spain, Svalbard, Sweden, Switzerland, Ukraine, Alaska, Alberta, Aleutian Is., British Columbia, California, Colorado, Greenland, Idaho, Labrador, Maine, Montana, Nevada, New Hampshire, New Mexico, Newfoundland, Northwest Territories, Nunavut, Oregon, Québec, Utah, Washington, Wyoming, Yukon AltayBuryatiyaIrkutskJapanKamchatkaKrasnoyarskMagadanMongoliaNorth CaucasusTranscaucasusTürkiyeTuvaWest SiberiaXinjiangYakutiyaEast HimalayaWest HimalayaAlbaniaAustriaBulgariaCentral European RussiaCorseCzechia-SlovakiaFinlandFranceGermanyGreeceIcelandItalyNorth European RussiaNorwayNW. Balkan Pen.PolandPortugalRomaniaSpainSvalbardSwedenSwitzerlandUkraineAlaskaAlbertaBritish ColumbiaCaliforniaColoradoGreenlandIdahoLabradorMaineMontanaNevadaNew HampshireNew MexicoNewfoundlandNorthwest TerritoriesNunavutOregonQuébecUtahWashingtonWyomingYukon Føroyar
Native distribution of Epilobium anagallidifolium, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows. Regions too small to draw at this scale are marked with a dot.
RegionTDWG codeContinent
Albania ALB EUROPE
Austria AUT
Bulgaria BUL
Central European Russia RUC
Corse COR
Czechia-Slovakia CZE
Finland FIN
Føroyar FOR
France FRA
Germany GER
Great Britain GRB
Greece GRC
Iceland ICE
Italy ITA
North European Russia RUN
Norway NOR
NW. Balkan Pen. YUG
Poland POL
Portugal POR
Romania ROM
Spain SPA
Svalbard SVA
Sweden SWE
Switzerland SWI
Ukraine UKR
Alaska ASK NORTHERN AMERICA
Alberta ABT
Aleutian Is. ALU
British Columbia BRC
California CAL
Colorado COL
Greenland GNL
Idaho IDA
Labrador LAB
Maine MAI
Montana MNT
Nevada NEV
New Hampshire NWH
New Mexico NWM
Newfoundland NFL
Northwest Territories NWT
Nunavut NUN
Oregon ORE
Québec QUE
Utah UTA
Washington WAS
Wyoming WYO
Yukon YUK
Altay ALT ASIA-TEMPERATE
Buryatiya BRY
Irkutsk IRK
Japan JAP
Kamchatka KAM
Krasnoyarsk KRA
Kuril Is. KUR
Magadan MAG
Mongolia MON
North Caucasus NCS
Transcaucasus TCS
Türkiye TUR
Tuva TVA
West Siberia WSB
Xinjiang CHX
Yakutiya YAK
East Himalaya EHM ASIA-TROPICAL
West Himalaya WHM

Not drawn on the map: Kuril Is., Great Britain, Aleutian Is.. We hold no public-domain boundary for these regions, so they are listed rather than guessed at.

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Flowering 43 in flower of 49 examined

Proportion of examined Epilobium anagallidifolium in flower, by month
Month In flower Examined Share 95% interval
Jan 0 0 too few examined
Feb 0 0 too few examined
Mar 0 0 too few examined
Apr 0 0 too few examined
May 0 0 too few examined
Jun 1 1 too few examined
Jul 24 26 92% 76% to 98%
Aug 18 21 86% 65% to 95%
Sep 0 1 too few examined
Oct 0 0 too few examined
Nov 0 0 too few examined
Dec 0 0 too few examined

Peak flowering in Jul. Each bar is the share of Epilobium anagallidifolium observations in which someone actually recorded the reproductive state and found the plant in flower, not the raw number of flowering records. That distinction matters: people observe plants far more in spring than in winter, so a bare count of flowering records partly measures when people go outside. Dividing by the number examined removes that. 43 of 49 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 10 months have fewer than 5 examined observations, so no proportion is drawn for them. This is still a global aggregate and not a forecast for your garden: the same species flowers on different dates in different hemispheres. Where a species has fewer than 30 flowering records we do not draw this chart at all. Computed from 10.15468/dl.cgje2x.

Where it actually grows measured, from 477 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -21.1 °C -14.6 °C -4.7 °C
Warmest month, mean daily high 10.7 °C 15.2 °C 20.2 °C
Annual rainfall 840 mm 1,765 mm 4,300 mm
Rainfall in the driest quarter 108 mm 277 mm 440 mm

It is found where winters are severely cold. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 477 research-grade observations of Epilobium anagallidifolium that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one. Climate from CHELSA V2.1 (Karger et al. 2017); occurrences from 10.15468/dl.cgje2x.

Also published as 11 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Epilobium alpinum subsp. anagallidifolium (Lam.) Čelak.
  • Epilobium alpinum var. fontanum Wahlenb.
  • Epilobium anagallidifolium f. scapoides E.S.Marshall
  • Epilobium anagallidifolium f. zapalowiczii Tacik
  • Epilobium anagallidifolium var. pseudoscaposum (Hausskn.) Hultén
  • Epilobium athelespermum H.Lév.
  • Epilobium cernuum Pall. ex Hausskn.
  • Epilobium dielsii H.Lév.
  • Epilobium nakaharanum Nakai
  • Epilobium pseudoscaposum Hausskn.
  • Epilobium repens Hill

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
  4. Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.