An annual of damp mud on the margins of ponds and lakes, canals, rivers and streams, or shallow depressions such as vehicle tracks and hoof-marks in woodland rides, around field gateways and in wet meadows. It is almost invariably in sites which are waterlogged in winter, often on base-poor soils and sometimes in partial shade. 0-505 m (Llyn Crugnant, Cards.).
The distribution of P. hydropiper has not changed markedly since the 1962 Atlas, although there have been losses at the eastern edge of its range.
Circumpolar Temperate element; widely naturalised outside its native range.
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
1986. Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols.
Jalas & Suominen (1979)
1981. Docks and knotweeds of the British Isles. Botanical Society of the British Isles Handbook no. 3.
1965. Vergleichende Chorologie der zentraleuropäischen Flora. Volume 1. 2 vols.
1966. Biological Flora of the British Isles. No. 103. Polygonum hydropiper L. Journal of Ecology. 54:815-821.