A perennial of wet ground, pools and hummocks in Sphagnum bogs, or at the edges of gently sloping mires where there is slight lateral water movement; such sites often occur on watersheds. It generally occurs in open ground, but sometimes persists in carr. From 30 m (Shian, Mid Perth), but generally upland, reaching 685 m (Ben Lui, Main Argyll).
C. magellanica is thinly scattered in suitable habitats. Some colonies have been lost as a result of drainage and afforestation but many new sites have been found, particularly in Wales, where it was collected c. 1835 but not refound until 1963, in Main Argyll and in N. Ireland.
Circumpolar Boreal-montane element.
Light (Ellenberg): 9
Moisture (Ellenberg): 9
Reaction (Ellenberg): 2
Nitrogen (Ellenberg): 1
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): 1.7
July Mean Temperature (Celsius): 12.8
Annual Precipitation (mm): 1808
Height (cm): 40
Perennation - primary
Life Form - primary
Clonality - primary
Count of 10km squares in Great Britain: 131
Count of 10km squares in Ireland: 8
Count of 10km squares in the Channel Isles: 0
Atlas Change Index: -0.02
Scarce Atlas Account
Carex magellanica Lam.
This is a perennial plant of wet level moorlands and occasionally clearings in swampy woods, where it grows in Sphagnum lawns and infilled hollows but, unlike its ally C. limosa, seldom in standing water. The two species sometimes grow close together in the same bog, but appear to have slightly different habitat requirements. C. magellanica is a sub-montane plant, mainly of upland blanket bogs and valley mires, from 370 metres to 658 metres near Cononish. Typical associates include Carex curta, C. echinata, C. pauciflora, Drosera rotundifolia, Narthecium ossifragum, Vaccinium oxycoccos, Viola palustris, Aulacomnium palustre, Sphagnum cuspidatum, S. papillosum and S. rubellum.
Unlike C. limosa, C. magellanica produces only short rhizomes and its often extensive colonies must be generated largely by seeds, although in some seasons the plants are very shy-flowering. Growth is often rather sparse but distinct tussocks occur on Armboth Fells.
It is surprisingly rare in the Scottish Highlands, and more frequent in Cumbria, while in the last thirty years, a number of colonies have been discovered on the borders of Montgomery and Merioneth and in Cardiganshire. Several sites have been destroyed by forestry operations and the plant is at risk from moor draining. It is probably still present in most of the 10 km squares for which only pre-1970 records are available.
This sedge is widespread in northern Europe from Iceland (where it is found at sea level) to Finland and northern Russia, but further south occurs only on the higher mountains. In Asia it is found in Siberia and Japan. In North America it is again frequent from Greenland to British Columbia, and locally as far south as Utah and Pennsylvania. The plant of the northern hemisphere is subspecies irrigua (Wahlenb.) Subsp. magellanica occurs in Chile and Patagonia near the Straits of Magellan.
R. W. David