A rhizomatous perennial herb of brackish ditches, dune-slacks and damp grasslands near the sea. It avoids areas of standing water. Lowland.
C. divisa suffered losses, particularly in S.W. England, before 1930. It remains frequent in suitable areas in S. and E. England, and there has been little change in its distribution since the 1962 Atlas despite local losses due to coastal development and the widespread conversion of grazing marshes to arable. In Ireland, the populations in Co. Dublin have been lost to building and it was considered to be extinct in Co. Kilkenny and Co. Wexford until re-discovered in 1990.
Light (Ellenberg): 8
Moisture (Ellenberg): 7
Reaction (Ellenberg): 7
Nitrogen (Ellenberg): 6
Salt Tolerance (Ellenberg): 3
January Mean Temperature (Celsius): 4.4
July Mean Temperature (Celsius): 16.4
Annual Precipitation (mm): 727
Count of 10km squares in Great Britain: 162
Count of 10km squares in Ireland: 4
Count of 10km squares in the Channel Isles: 1
Atlas Change Index: -0.35
Scarce Atlas Account
Carex divisa Hudson
A perennial sedge of grassland near the sea, C. divisa is moderately tolerant of salt, but absent from saltmarshes themselves. It is particularly characteristic of lightly grazed depressions in coastal pastures and the margin of grazing-marsh ditches on alluvial or sandy soils. It often accompanies Carex distans, Oenanthe lachenalii and Trifolium fragiferum in the damp brackish sward. C. divisa rarely occurs above 10 metres altitude, although it does occur on the inland margins of grazing marshes.
C. divisa has a far-creeping rhizome and much of its local spread is by vegetative means. Longer-distance dispersal by seed is frequent.
C. divisa is declining within most of its British range, and has disappeared from its inland sites. Many populations have been lost as a result of ploughing, drainage and industrial development of coastal grasslands (in particular the conversion of grazing marsh to arable land); increasing control of tidal water may also have contributed to its demise on some sites, by reducing the occurrence of brackish conditions inland.
C. divisa occurs inland in southern and south-central Europe, but is mainly coastal further north; it reaches its northern limit in Britain. It is also widespread in Mediterranean north Africa and west Asia.
J. O. Mountford
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
1994. The re-discovery of Carex divisa Hudson, Divided Sedge, in Ireland. Irish Naturalists’ Journal. 24:496-498.
1988. The Irish Red Data Book. 1. Vascular Plants.
1982. Sedges of the British Isles. Botanical Society of the British Isles Handbook no. 1, edn 2.
1994. Scarce plants in Britain.