Rhynchospora fusca

Ecology

A rhizomatous perennial of wet heaths, and the margins of acidic mires, favouring bare peat where competition is limited but preferring somewhat drier sites than R. alba in the south of its range. It spreads vegetatively, and may reproduce by seed. Lowland.

Status

Native

World Distribution

Suboceanic Boreo-temperate element; also in N. America.

© K.J. Walker, BSBI

Broad Habitats

Bog

Light (Ellenberg): 9

Moisture (Ellenberg): 9

Reaction (Ellenberg): 3

Nitrogen (Ellenberg): 1

0

Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 4.4

July Mean Temperature (Celsius): 14.7

Annual Precipitation (mm): 1205

Life form information

Height (cm): 30

Perennation - primary

Perennial

Life Form - primary

Hemicryptophyte

Woodiness

Herbaceous

Clonality - primary

Rhizome far-creeping

Count of 10km squares in Great Britain: 46

Count of 10km squares in Ireland: 94

Count of 10km squares in the Channel Isles: 0

Atlas Change Index: 0.02

Distribution information

JNCC Designations

NHMSYS0000462390

Scarce Atlas Account

Scarce Atlas Account: 

Rhynchospora fusca (L.) Alton f.

Brown beak-sedge

Status: scarce

 

This is a perennial found on wet heaths and the margins of acid bogs, often on bare peat. It usually avoids the very wettest areas. It can be found with Eleocharis multicaulis, Eriophorum angustifolium, Juncus bulbosus, Narthecium ossifragum, Rhynchospora alba and Sphagnum species, and occasionally with Lycopodiella inundata, but on bare peat it is often the only species present. It will gradually give way to other plants, particularly Molinia caerulea, as the habitat dries out. It is confined to the lowlands.

R. fusca actively spreads by rhizomes. It will readily colonise bare peat, and has re-established itself in sites where the invading vegetation and top 2 cm of peat has been removed. This suggests reproduction by seed, but further work is necessary to establish this. Colonies are usually small, but can occasionally be very large indeed. Dead flowering stems persist through the winter and can be identified as late as March.

The species is certainly declining in southern Britain. It has not been seen in Somerset since 1970, when the site was destroyed by peat cutting. In areas where it has survived habitat destruction, cessation of grazing is a much greater threat now than drainage or improvement. In Dorset, 17 of the 27 sites in which it was recorded in a survey made in 1932-38 are now lost, almost entirely to invading carr. It is holding its own in Wales and it has been discovered at several Scottish localities in recent years: it is currently known in five Scottish vice-counties, compared to two in 1962. 

It is widespread in western Ireland, but its current status in central Ireland is unknown. It also occurs in north-western and central Europe, being commoner in the north and west, and in north-eastern America.

 

D. A. Pearman

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 (353a)
Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols,
Hultén, E., and Fries M.
, Königstein, (1986)

Vergleichende Chorologie der zentraleuropäischen Flora. Volume 1. 2 vols,
Meusel, H., Jäger E., and Weinert E.
, Jena, (1965)

Scarce plants in Britain,
Stewart, A., Pearman D. A., and Preston C. D.
, Peterborough, (1994)