Apium nodiflorum (Fool`s-water-cress)


Summary Information


A perennial herb, found in shallow water in streams, ditches, swamps and marshes, and on seasonally exposed mud at the edges of ponds, lakes, rivers and canals, sometimes scrambling into nearby vegetation. It is characteristic of nutrient-enriched sites. Generally lowland, but reaching 335 m E. of Shap (Westmorland).



World Distribution

Eurosiberian Southern-temperate element; widely naturalised outside its native range.


Photos Information


Habitats Information

Broad Habitats

Rivers and streams

Light (Ellenberg): 7 Information

Moisture (Ellenberg): 10 Information

Reaction (Ellenberg): 7 Information

Nitrogen (Ellenberg): 7 Information

Salt Tolerance (Ellenberg): 0 Information

January Mean Temperature (Celsius): 4 Information

July Mean Temperature (Celsius): 15.2 Information

Annual Precipitation (mm): 961 Information

Life Form

Life Form Information

Height (cm): 60

Length: 100

Perennation - primary


Perennation - secondary

Life Form - primary

Perennial hydrophyte (perennial water plant)

Life Form - secondary



Clonality - primary

Irregularly fragmenting (mainly water plants)

Clonality - secondary


Distribution Information

Count of 10km squares in Great Britain: 1661

Count of 10km squares in Ireland: 855

Count of 10km squares in the Channel Isles: 12

Atlas Change Index: -0.31

Weighted Changed Factor: 14

Weighted Change Factor Confidence (90%)


Conservation Status

Conservation Status Information

Plantatt Conservation Status

Other Accounts

Other Accounts Information


References Information

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 (158d)
Grime JP, Hodgson JG, Hunt R.  1988.  Comparative Plant Ecology.
Preston CD, Croft JM.  1997.  Aquatic plants in Britain and Ireland.
Tutin TG.  1980.  Umbellifers of the British Isles. Botanical Society of the British Isles Handbook no. 2.