Carex dioica

Tracheophyta MagnoliopsidaCyperaceaeCarexCarex dioica


A shortly rhizomatous perennial herb of very wet, neutral to base-rich mires. It grows particularly well in silty, calcareous mud and by the edges of lime-rich flushes and springs. Although it occurs at sea level, many sites are at moderate or high altitudes, ascending to about 1000 m on Ben Lawers (Mid Perth).



World Distribution

Circumpolar Boreo-arctic Montane element.

Broad Habitats

Fen, marsh and swamp (not wooded)

Light (Ellenberg): 8

Moisture (Ellenberg): 9

Reaction (Ellenberg): 6

Nitrogen (Ellenberg): 2


Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 2.7

July Mean Temperature (Celsius): 13.2

Annual Precipitation (mm): 1404

Life form information

Height (cm): 30

Perennation - primary


Life Form - primary




Clonality - primary

Rhizome shortly creeping

Distribution information

Count of 10km squares in Great Britain: 1100

Count of 10km squares in Ireland: 204

Count of 10km squares in the Channel Isles: 0

Atlas Change Index: -0.35

Weighted Changed Factor: 17

Weighted Change Factor Confidence (90%)


Distribution information

JNCC Designations


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