Cicuta virosaL.

European WaterhemlockMackenzie's water hemlockcowbane

WFO wfo-0000604532 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Cicuta virosa, photographed by Eugene Popov
fig. a Eugene Popov, CC BY 4.0 / 2022-06-12 / obs. 205731870
Cicuta virosa, photographed by aga_l_
fig. b aga_l_, CC BY 4.0 / obs. 205201647
Cicuta virosa, photographed by Нурхайдарова Татьяна
fig. c Нурхайдарова Татьяна, CC BY 4.0 / obs. 201551566
Cicuta virosa, photographed by Елена Кизилова
fig. d Елена Кизилова, CC BY 4.0 / obs. 197734903
Cicuta virosa, photographed by Marina Potapova
fig. e Marina Potapova, CC0 1.0 / obs. 162608186
Cicuta virosa, photographed by Tatiana Strus
fig. f Tatiana Strus, CC BY 4.0 / obs. 161873626
Cicuta virosa, photographed by Tatiana Strus
fig. g Tatiana Strus, CC BY 4.0 / obs. 157353058
Cicuta virosa, photographed by Марина Садыкова
fig. h Марина Садыкова, CC BY 4.0 / obs. 156926638

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 68 botanical countries

Regions where Cicuta virosa is native: Altay, Amur, Buryatiya, China North-Central, China South-Central, Chita, Inner Mongolia, Irkutsk, Japan, Kamchatka, Kazakhstan, Khabarovsk, Kirgizstan, Korea, Krasnoyarsk, Kuril Is., Magadan, Manchuria, Mongolia, North Caucasus, Palestine, Primorye, Sakhalin, Transcaucasus, Türkiye, Tuva, West Siberia, Xinjiang, Yakutiya, West Himalaya, Austria, Baltic States, Belarus, Belgium, Bulgaria, Central European Russia, Czechia-Slovakia, Denmark, East European Russia, Finland, France, Germany, Great Britain, Greece, Hungary, Ireland, Italy, Netherlands, North European Russia, Northwest European Russia, Norway, NW. Balkan Pen., Poland, Romania, South European Russia, Sweden, Switzerland, Ukraine, Alaska, Alberta, British Columbia, Manitoba, Northwest Territories, Nunavut, Ontario, Québec, Saskatchewan, Yukon AltayAmurBuryatiyaChina North-CentralChina South-CentralChitaInner MongoliaIrkutskJapanKamchatkaKazakhstanKhabarovskKirgizstanKrasnoyarskMagadanManchuriaMongoliaNorth CaucasusPalestinePrimoryeSakhalinTranscaucasusTürkiyeTuvaWest SiberiaXinjiangYakutiyaWest HimalayaAustriaBaltic StatesBelarusBelgiumBulgariaCentral European RussiaCzechia-SlovakiaDenmarkEast European RussiaFinlandFranceGermanyGreeceHungaryIrelandItalyNetherlandsNorth European RussiaNorthwest European RussiaNorwayNW. Balkan Pen.PolandRomaniaSouth European RussiaSwedenSwitzerlandUkraineAlaskaAlbertaBritish ColumbiaManitobaNorthwest TerritoriesNunavutOntarioQuébecSaskatchewanYukon Korea
Native distribution of Cicuta virosa, 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
Altay ALT ASIA-TEMPERATE
Amur AMU
Buryatiya BRY
China North-Central CHN
China South-Central CHC
Chita CTA
Inner Mongolia CHI
Irkutsk IRK
Japan JAP
Kamchatka KAM
Kazakhstan KAZ
Khabarovsk KHA
Kirgizstan KGZ
Korea KOR
Krasnoyarsk KRA
Kuril Is. KUR
Magadan MAG
Manchuria CHM
Mongolia MON
North Caucasus NCS
Palestine PAL
Primorye PRM
Sakhalin SAK
Transcaucasus TCS
Türkiye TUR
Tuva TVA
West Siberia WSB
Xinjiang CHX
Yakutiya YAK
Austria AUT EUROPE
Baltic States BLT
Belarus BLR
Belgium BGM
Bulgaria BUL
Central European Russia RUC
Czechia-Slovakia CZE
Denmark DEN
East European Russia RUE
Finland FIN
France FRA
Germany GER
Great Britain GRB
Greece GRC
Hungary HUN
Ireland IRE
Italy ITA
Netherlands NET
North European Russia RUN
Northwest European Russia RUW
Norway NOR
NW. Balkan Pen. YUG
Poland POL
Romania ROM
South European Russia RUS
Sweden SWE
Switzerland SWI
Ukraine UKR
Alaska ASK NORTHERN AMERICA
Alberta ABT
British Columbia BRC
Manitoba MAN
Northwest Territories NWT
Nunavut NUN
Ontario ONT
Québec QUE
Saskatchewan SAS
Yukon YUK
West Himalaya WHM ASIA-TROPICAL

Not drawn on the map: Kuril Is., Great Britain. 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 131 in flower of 231 examined

Peak flowering in Jul. Each bar is the share of Cicuta virosa 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. 131 of 231 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 6 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.

Also published as 27 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.

  • Cicuta angustifolia Kit.
  • Cicuta baldacciana Degen ex Bald.
  • Cicuta cellulosa Gilib.
  • Cicuta mackenzieana Raup
  • Cicuta nipponica Franch.
  • Cicuta orientalis Degen
  • Cicuta pumila F.Behm
  • Cicuta tenuifolia Schrank
  • Cicuta virosa f. angustifolia (Kit.) Regel
  • Cicuta virosa f. angustifolia (Kit.) Schube
  • Cicuta virosa f. latisecta (Čelak.) Y.C.Chu
  • Cicuta virosa f. longiinvolucellata Chu
  • Cicuta virosa var. angustifolia (Kit. ex Schult.) Schltdl.
  • Cicuta virosa var. angustisecta Čelak.
  • Cicuta virosa var. intermedia Glaab
  • Cicuta virosa var. latifolia Schltdl.
  • Cicuta virosa var. latisecta Čelak.
  • Cicuta virosa var. nipponica (Franch.) Makino
  • Cicuta virosa var. orientalis Degen & Bald.
  • Cicuta virosa var. stricta Schultz
  • Cicuta virosa var. tenuifolia (Schrank) Roth
  • Cicuta virosa var. virosa
  • Cicutaria aquatica Lam.
  • Cicutaria virosa Delarbre

and 3 more.

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.