Cicuta virosa

Tracheophyta MagnoliopsidaApiaceaeCicutaCicuta virosa


This perennial herb grows in shallow water on the margins of standing or slowly flowing water, including lakes, ponds, rivers, streams, ditches and canals, or in deeper water on floating mats of vegetation. It also occurs in tall-herb fen, in marshy pasture and on damp mud. Lowland.



World Distribution

Eurasian Boreo-temperate element, with a continental distribution in W. Europe.

Broad Habitats

Light (Ellenberg): 7

Moisture (Ellenberg): 10

Reaction (Ellenberg): 7

Nitrogen (Ellenberg): 5

Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 3.5

July Mean Temperature (Celsius): 14.8

Annual Precipitation (mm): 926

Height (cm): 150

Perennation - primary


Life Form - primary

Perennial hydrophyte (perennial water plant)



Clonality - primary

Little or no vegetative spread

Count of 10km squares in Great Britain: 139

Count of 10km squares in Ireland: 139

Count of 10km squares in the Channel Isles: 0

Atlas Change Index: 0.55

JNCC Designations


External Species Accounts

Scarce Atlas Account

Scarce Atlas Account: 

Cicuta virosa L.


Status: scarce



This is an aquatic species of lake shores, pond margins, mires and ditches. It grows in shallow water or on a floating mat of vegetation and has a wide pH tolerance. Associates include such species as Angelica sylvestris, Carex paniculata, C. riparia, C. rostrata, Phalaris arundinacea, Phragmites australis, Potentilla palustris, Ranunculus hederaceus, R. lingua, R. sceleratus and Typha latifolia. It is restricted to the lowlands. 

C. virosa is perennial. It reproduces by seed and sometimes forms rather dense colonies in mires.

C. virosa has probably always been local. It has disappeared from many sites in eastern England because of drainage. It contains a convulsant poison, cicutoxin, which is frequently fatal to cattle, and has perhaps been selectively eliminated from some areas by man. Many of the remaining populations are stable. It persists in sites where the water has become eutrophic and many submerged species have disappeared.

Widespread from Britain and Ireland east to eastern Siberia and Japan, becoming more scattered in the western part of its range and virtually absent from the Mediterranean region. Closely related species occur in North America.



M. E. Braithwaite

Atlas text references

Atlas (160b) Hultén E, Fries M
1986.  Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols. Meusel H, Jäger E, Rauschert S, Weinert E
1978.  Vergleichende Chorologie der zentraleuropäischen Flora. Volume 2. 2 vols. Mulligan GA, Munro DB
1981.  The biology of Canadian weeds. 48. Cicuta maculata L., C. douglasii (DC.) Coult. & Rose and C. virosa L. Canadian Journal of Plant Science. 61:93-105. Stewart A, Pearman DA, Preston CD
1994.  Scarce plants in Britain. Tutin TG
1980.  Umbellifers of the British Isles. Botanical Society of the British Isles Handbook no. 2.