A rhizomatous perennial herb of marshes and wet pastures near the coast, and sometimes in base-rich flushes on sea-cliffs. It also occurs on pond margins and in ditches inland, where it is usually planted. Reproduction is through vigorous rhizomatous spread, and it may not set seed in Britain. Lowland.
Since the 1962 Atlas this species has apparently been lost from some native sites because of agricultural change, including the cessation of grazing. However, new native sites have been discovered since 1960, notably in N. Wales, and the number of introduced sites has increased very considerably.
European Southern-temperate element.
Count of 10km squares in Great Britain: 33
Count of 10km squares in Ireland: 0
Count of 10km squares in the Channel Isles: 12
Atlas Change Index: 2.22
Scarce Atlas Account
Cyperus longus L.
C. longus is found in marshes and wet pastures near the coast, particularly in valleys and also in base-rich flushes on the cliffs.
It is a rhizomatous perennial, forming vigorously spreading patches that may extend over a considerable area, eliminating most competition. The seed may well not ripen in Britain (Syme 1870).
The species seems to have declined in localities where it is almost indisputably native. However, it was used agriculturally in the Channel Islands and so it may have been planted at some of these sites. It has gone from many of the coastal sites shown in the Atlas (Perring & Walters 1962), through drainage and agricultural improvement of habitat, and through cessation of grazing which has led to outcompetition by Oenanthe crocata, or invasion by alder scrub. However, there are also many recent records from ponds and ditches all over southern England. It is widely available horticulturally, especially at aquatic garden centres, and at many sites is clearly deliberately introduced.
It is common over all western, central and southern Europe, east to central Asia, and in North and East Africa.
D. A. Pearman
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.