A rhizomatous perennial found in standing or slowly flowing water in sheltered lakes and reservoirs, ponds, rivers, canals, ditches and flooded mineral workings. It favours mesotrophic to eutrophic water and tolerates slightly brackish conditions. 0-320 m (Stony Middleton, Derbys.).
P. pusillus and P. berchtoldii were confused in our area until 1938. Any assessment of changes in their distribution must therefore be based on very limited evidence, especially as they may still be under-recorded. However, comparison of pre-1930 and recent records suggests that P. pusillus may have increased in some areas, perhaps in response to eutrophication.
Circumpolar Southern-temperate element.
Perennation - primary
Life Form - primary
Clonality - primary
Comment on Clonality
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 of north European vascular plants north of the Tropic of Cancer. 3 vols,
, Königstein, (1986)
Pondweeds of Great Britain and Ireland. Botanical Society of the British Isles Handbook no. 8,
, London, (1995)
Aquatic plants in Britain and Ireland,
, Colchester, (1997)