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.
Many losses of C. virosa are probably due to drainage, but it may have been eradicated from some pastures because of its toxicity to cattle. Some losses were very early: the last record in Cambridgeshire, for example, was made in the 18th century. However, the distribution now seems largely stable.
Eurasian Boreo-temperate element, with a continental distribution in W. Europe.
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
External Species Accounts
Scarce Atlas Account
Cicuta virosa L.
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
PLANTATT - Attributes of British and Irish plants. (.zip 1455KB) This dataset was compiled and published in 2004, and last updated in November 2008. Download includes an Excel spreadsheet of the attributes, and a PDF explaining the background and nomenclature. Note that the PDF version is the booklet as published, whereas the Excel spreadsheet incorporates subsequent corrections. A hardcopy can be purchased from the Centre for Ecology and Hydrology.
Atlas text references
Atlas (160b) Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols,
, Königstein, (1986)
Vergleichende Chorologie der zentraleuropäischen Flora. Volume 2. 2 vols,
, Jena, (1978)
The biology of Canadian weeds. 48. Cicuta maculata L., C. douglasii (DC.) Coult. & Rose and C. virosa L,
, Canadian Journal of Plant Science, Volume 61, p.93-105, (1981)
Scarce plants in Britain,
, Peterborough, (1994)
Umbellifers of the British Isles. Botanical Society of the British Isles Handbook no. 2,
, London, (1980)