A densely tufted perennial herb of open situations, occurring in stony flushes, base-rich mires and wet, grassy or sedge-rich turf on limestone or calcareous mica-schist. Generally montane, occurring as low as 360 m in Teesdale (N.W. Yorks.) but reaching 1065 m on Meall Garbh (Mid Perth).
The distribution of K. simpliciuscula is stable. Even when common, however, it is easy to overlook and it probably still occurs in most sites for which there are only pre-1987 records. Some populations are very extensive with tens of thousands of plants.
Circumpolar Arctic-montane element.
Light (Ellenberg): 8
Moisture (Ellenberg): 8
Reaction (Ellenberg): 8
Nitrogen (Ellenberg): 1
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): -0.1
July Mean Temperature (Celsius): 11.5
Annual Precipitation (mm): 2044
Height (cm): 20
Perennation - primary
Life Form - primary
Clonality - primary
Count of 10km squares in Great Britain: 18
Count of 10km squares in Ireland: 0
Count of 10km squares in the Channel Isles: 0
Atlas Change Index: 0.58
RDB Species Accounts
Kobresia simpliciuscula (Wahlenb.) Mackenzie (Cyperaceae)
Status in Britain: LOWER RISK - Near Threatened.
Status in Europe: Not threatened.
This is a montane plant of calcareous stony and grassy flushes, small-sedge mires and, in Teesdale, sugar limestone grassland. In Scotland, the populations are centred on the Breadalbane mountains and on the limestones of Perthshire, the plant mainly occurring in mid- and east Perth, with outposts in Argyll. It ascends to over 1,000 metres. In northern England, it occurs chiefly in Upper Teesdale, where it was first recorded in Britain in 1797. The underlying geology is invariably calcareous, the base-rock either limestone or calcareous mica-schist. Its communities are typically open and sedge-dominated, and grazed to a varying extent by sheep and/or red deer, leading to variable flowering. It grows in pure mats, or in herb-rich swards in flushed ground and mires with Carex capillaris, C. dioica, C. hostiana, C. viridula ssp. brachyrrhyncha, C. panicea, C. pulicaris, Juncus articulatus, J. triglumis, Molinia caerulea, Pinguicula vulgaris, Primula farinosa, Saxifraga aizoides, Selaginella selaginoides, Thalictrum alpinum and Tofieldia pusilla. In Teesdale, it also occurs as isolated clumps with Carex viridula ssp. brachyrrhyncha, Juncus articulatus and Minuartia verna in open gravel flushes of sugar limestone (Pigott 1956).
K. simpliciuscula is a perennial which grows in rather dense tufts 5-20 cm in height bearing an inflorescence of 3-10 crowded spikes. It is wind-pollinated and flowers in June and July. Patches extend through vegetative growth, and individual plants are relatively long-lived. However, reproduction by seed can take place, germination occurring where the vegetation is open.
In Upper Teesdale, populations are large and extensive, comprising many thousands of plants, though a significant portion of the British population was drowned by the Cow Green reservoir. In Perthshire, most populations are small, but in the area south of the River Tilt, there are several flush systems with hundreds of plants, and more than 10,000 at one site. There is a surprising lack of recent records from the central Breadalbanes, perhaps because it is generally assumed not to be threatened there. It is quite likely that K. simpliciuscula still occurs at most or all of its known sites, and that the map does not fully represent its current status.
A few populations of K. simpliciuscula are subject to heavy grazing which can, however, be tolerated for many years, the plants reproducing vegetatively and producing few, if any, flowers. Its range appears not to have altered in recent years, and it is not regarded as seriously under threat. Sites are generally too high for afforestation and agricultural land claim, and most of its locations lie within SSSIs.
K. simpliciuscula also occurs in the Pyrenees, Alps, Caucasus and Altai mountains, in Scandinavia, Greenland and North America.
R. A. H. Smith