Carex microglochin (Bristle Sedge)
A shortly-rhizomatous perennial herb of base-rich flushes on gently sloping or `stepped` ground on micaceous silt or gravel. Also, occasionally, on steep burn-sides downstream of large colonies. Reproduction appears to be mainly vegetative. Between 610 m and 975 m on Ben Lawers (Mid Perth).
Regular monitoring since the 1980s has shown little change in the distribution of the many colonies of C. microglochin within the only 10-km square from which it is recorded.
European Arctic-montane element; also in C. Asia and N. & S. America.
Count of 10km squares in Great Britain: 1
Count of 10km squares in Ireland: 0
Count of 10km squares in the Channel Isles: 0
RDB Species Accounts
Carex microglochin Wahlenb. (Cyperaceae)
Bristle sedge, Seisg Chalgach
Status in Britain: VULNERABLE.
Status in Europe: Not threatened.
Before C. microglochin was first found in Britain, the possibility that it grew here had long haunted the botanist G.C.Druce. He searched for it in vain for many years in the Highlands of Scotland and also as far north as Shetland. It was eventually found in 1923, not by Druce, but by two ladies who had become separated from the main body of an expedition paying its respects to Carex atrofusca (Payne & Geddes 1980). It is a plant of moderately high-level base-enriched flushes ranging from 580 to 975 metres altitude, but usually between 700 and 900 metres. The flushes are mostly gently sloping, sometimes with steeper 'steps', and with a small to moderate water flow over the weakly acidic to weakly alkaline micaceous silt or gravelly substrate (Raven & Walters 1956, Evans 1982, Boddington 1995). The sites are rich in calcium, and the plant can tolerate high levels of magnesium, though is not dependent on it (Boddington 1995). The cover of vascular plants varies from less than 50% to nearly 100%, and bryophytes are usually abundant. Associates usually include Carex dioica, C. panicea, C. viridula ssp. brachyrrhyncha, Eleocharis quinqueflora, Juncus alpinus, Pinguicula vulgaris, Saxifraga aizoides, Blindia acuta, Calliergon trifarium and Scorpidium scorpioides. The flushes are mostly surrounded by Nardus stricta-dominated grassland. It has also been found in small quantities on steep ground beside burns downstream of large colonies, and in marshes with much Equisetum palustre.
This species is a perennial with a short, creeping, slender rhizome, and normally single shoots (Jermy, et al. 1982). Flowering is usually in early July, but may often be delayed by late snow-lie until late July or early August. Utricles mature and become reflexed by late July to mid-August, and then are gradually shed. Large fluctuations occur in the numbers of stems grown from year to year.
C. microglochin is recorded only from the Ben Lawers range, Perthshire, the whole population encompassed within a single hectad. It is distributed over a sizeable complex of flush systems on the slopes of two mountains, mostly in three corries and on an adjacent col, but with smaller, scattered, outlying colonies. It is very abundant in some flush systems. A reliable estimate of population size has not been possible since only flowering or fruiting stems are conspicuous and distinctive enough to be counted, and these may be grazed. However, regular monitoring between the 1980s and 1996 has shown little change in its distribution.
The whole known range is subject to intensive sheep-grazing and a much lower intensity of deer-grazing. C. microglochin is grazed by sheep, and colonies are damaged by poaching of the soft substrate. There is some indication of a population increase where sheep-grazing is prevented (D.Mardon, pers. obs.).
Despite the whole population being geographically remote and lying within an NNR, C. microglochin is threatened in a number of ways. The most serious stems from proposed major changes in grazing regimes, including the erection of permanent stock fencing, which is considered likely to have an adverse effect on both the plant and its habitat. Walkers are a threat locally, and all-terrain vehicles and mountain bikes (increasingly used) have also caused habitat damage in the same area.
C. microglochin has an arctic-alpine circumpolar distribution, including Iceland, Scandinavia, the mountains of central and eastern Europe to the Caucasus, the mountains of Asia and Siberia, in North America from Alaska and British Columbia to Labrador and Newfoundland, and in Greenland (Benum 1958). In Scandinavia it also grows within submontane woodland.
D. K. Mardon
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 of north European vascular plants north of the Tropic of Cancer. 3 vols,
, Königstein, (1986)
Sedges of the British Isles. Botanical Society of the British Isles Handbook no. 1, edn 2,
, London, (1982)
Vergleichende Chorologie der zentraleuropäischen Flora. Volume 1. 2 vols,
, Jena, (1965)
British Red Data Books. 1. Vascular plants, edn 3,
, Peterborough, (1999)