Carex acutiformis

Tracheophyta MagnoliopsidaCyperaceaeCarexCarex acutiformis


This rhizomatous perennial herb grows in base-rich, mesotrophic and eutrophic water, often occurring in extensive stands. Its habitats include river banks, lakes and pond margins, marshy areas near streams, fen-meadows and tall-herb fen, and carr; it is notably shade-tolerant. It avoids sites subject to marked fluctuations in water level. Reproduction by seed is poor. 0-370 m (near Garrigill, Cumberland).



World Distribution

Eurosiberian Temperate element.

© P. Shannon

Broad Habitats

Fen, marsh and swamp (not wooded)

Light (Ellenberg): 7

Moisture (Ellenberg): 9

Reaction (Ellenberg): 7

Nitrogen (Ellenberg): 6

Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 3.5

July Mean Temperature (Celsius): 15.3

Annual Precipitation (mm): 889

Height (cm): 150

Perennation - primary


Life Form - primary


Life Form - secondary

Perennial hydrophyte (perennial water plant)



Clonality - primary

Rhizome far-creeping

Count of 10km squares in Great Britain: 1501

Count of 10km squares in Ireland: 195

Count of 10km squares in the Channel Isles: 1

Atlas Change Index: 0.16

Weighted Changed Factor: -2

Weighted Change Factor Confidence (90%)


JNCC Designations


Atlas text references

Atlas (358c)
Grime JP, Hodgson JG, Hunt R
1988.  Comparative Plant Ecology.
Hultén E, Fries M
1986.  Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols.
Jermy AC, Chater AO, David RW
1982.  Sedges of the British Isles. Botanical Society of the British Isles Handbook no. 1, edn 2.
Meusel H, Jäger E, Weinert E
1965.  Vergleichende Chorologie der zentraleuropäischen Flora. Volume 1. 2 vols.
Preston CD, Croft JM
1997.  Aquatic plants in Britain and Ireland.