Carex magellanica (Tall Bog-sedge)


Summary Information


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).



World Distribution

Circumpolar Boreal-montane element.


Photos Information


Habitats Information

Broad Habitats


Light (Ellenberg): 9 Information

Moisture (Ellenberg): 9 Information

Reaction (Ellenberg): 2 Information

Nitrogen (Ellenberg): 1 Information

Salt Tolerance (Ellenberg): 0 Information

January Mean Temperature (Celsius): 1.7 Information

July Mean Temperature (Celsius): 12.8 Information

Annual Precipitation (mm): 1808 Information

Life Form

Life Form Information

Height (cm): 40

Perennation - primary


Perennation - secondary

Life Form - primary


Life Form - secondary



Clonality - primary

Rhizome shortly creeping

Clonality - secondary


Distribution Information

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

Conservation Status

Conservation Status Information

Plantatt Conservation Status

Other Accounts

Other Accounts Information

Scarce Atlas Account

Carex magellanica Lam.               

Tall bog-sedge

Status: scarce


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


References Information

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

Atlas (360c)
Curtis TGF, McGough HN.  1988.  The Irish Red Data Book. 1. Vascular Plants.
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.
Stewart A, Pearman DA, Preston CD.  1994.  Scarce plants in Britain.