A perennial herb of wet woodlands, especially those dominated by Alnus and those on lake shores, but also found on pond margins, in ditches and seasonally flooded areas, and in wet meadows. In favourable conditions it can form large, loose tussocks and it sets seed freely in more open situations. Lowland.
Some populations of C. elongata which were recorded before 1930 have been lost because of drainage and other forms of habitat destruction. The distribution is otherwise stable, and the species is better recorded in Ireland than in the 1962 Atlas.
Eurosiberian Boreal-montane element, with a continental distribution in W. Europe.
Light (Ellenberg): 5
Moisture (Ellenberg): 8
Reaction (Ellenberg): 6
Nitrogen (Ellenberg): 6
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): 3.6
July Mean Temperature (Celsius): 15.5
Annual Precipitation (mm): 899
Height (cm): 80
Perennation - primary
Life Form - primary
Clonality - primary
Count of 10km squares in Great Britain: 72
Count of 10km squares in Ireland: 18
Count of 10km squares in the Channel Isles: 0
Atlas Change Index: 0.06
External Species Accounts
Scarce Atlas Account
Carex elongata L.
C. elongata is a plant of lowland ponds, canal sides and wet woods and is more rarely found beside lakes in occasionally flooded meadows. It cannot tolerate continuous swamp conditions and benefits from winter flooding and drying out in summer. A characteristic habitat is decaying alder or willow carr, where the plant is often epiphytic on fallen boughs that keep it above summer water level with its roots still wet. It also favours stagnant ditches in water-meadows, and canals where the ancient wooden camp-sheathing provides the kind of pedestal that it enjoys.
C. elongata is a perennial species. In suitable conditions and not too much shade it seeds freely, but one of the largest and most floriferous colonies in England at Askham Bog seldom sets viable seed (Fitter & Smith 1979). Individual tussocks may become substantial but soon decay if conditions are not right. The plant seems unable to colonise newly exposed mud either vegetatively (the rhizomes are very short) or by seed.
Reclamation of marshes, the rehabilitation of canals for recreation, especially that involving strengthening of the banks with metal sheathing, and the infilling of pits and ponds have greatly reduced or extinguished many populations. The early British records were mostly from canals in the Manchester area, where the sedge was abundant, but the whole area has been reclaimed and the sedge has now gone. In recent years fine colonies have been discovered in Wales and several around Loch Lomond.
In Europe this sedge reaches as far north as the subarctic zone in Norway and Russia but is not found south of central France and northern Spain and Italy. It extends eastward to the Caucasus.
For a detailed account of the British distribution, see David (1978b, 1982a).
R. W. David
Atlas text references
1988. The Irish Red Data Book. 1. Vascular Plants.
David (1978b) .
1986. Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols. .
1982. Sedges of the British Isles. Botanical Society of the British Isles Handbook no. 1, edn 2. .
1965. Vergleichende Chorologie der zentraleuropäischen Flora. Volume 1. 2 vols. .
1994. Scarce plants in Britain.