A perennial herb of skeletal, well-drained soils on S.-facing slopes overlying Carboniferous limestone. It grows in open grassland, on rocky outcrops, screes, crags and limestone pavements, and occasionally also in partial shade in open limestone woodland. Lowland to 600 m on Long Fell, Warcop (Westmorland).
C. ornithopoda is still very localised, but its known range has been extended since the 1962 Atlas by discoveries in Cumberland and Yorkshire. Populations may be increasing in Westmorland, but plants are often vulnerable to intensive grazing by sheep.
European Boreal-montane element.
Light (Ellenberg): 8
Moisture (Ellenberg): 3
Reaction (Ellenberg): 9
Nitrogen (Ellenberg): 3
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): 2.1
July Mean Temperature (Celsius): 13.8
Annual Precipitation (mm): 1272
Height (cm): 15
Perennation - primary
Life Form - primary
Clonality - primary
Count of 10km squares in Great Britain: 15
Count of 10km squares in Ireland: 0
Count of 10km squares in the Channel Isles: 0
Atlas Change Index: 0.28
RDB Species Accounts
Carex ornithopoda Wild. (Cyperaceae)
Status in Britain: LOWER RISK - Near Threatened.
Status in Europe: Not threatened.
C. ornithopoda is a plant of open calcareous grasslands on Carboniferous limestone in Cumbria, Yorkshire and Derbyshire. It often grows close to exposed rocks on south-facing slopes in full sun where the soils are thin and have a tendency to become parched during the summer months. Such situations enable the species to avoid competition from bulkier associates. In Cumbria it is typically found in swards dominated by Sesleria caerulea, many of the most extensive populations being closely associated with areas of shattered limestone pavement. However, at a number of Cumbrian sites the dominant grass is Festuca ovina, and this is the case at both of the Derbyshire localities. Typical associates in the characteristically species-rich swards include Carex flacca, Helianthemum nummularium, Linum catharticum, Scabiosa columbaria and Thymus polytrichus.
C. ornithopoda is a perennial which flowers on lateral shoots. It is best identified when in fruit during May and June. Fertile seed is freely produced.
In Cumbria about 25 populations are shared between two main areas, one on the limestone scars to the north of Morecambe Bay and a second on cooler and higher exposures to the east of Shap. An outlying colony has also been detected further north in the Eden valley (Corner & Roberts 1989). Over 100 km to the south-east there are two substantial populations in Derbyshire's White Peak, and a colony of more than a hundred plants was discovered in 1992 at Twisleton Glen in Yorkshire. Confusion between C. ornithopoda and Carex digitata undoubtedly occurs, and a number of hitherto accepted records may well refer to the latter species. This is a particular problem where identification has been based on immature or non-fruiting specimens (David 1980a). Two historical records, from Mackershaw near Ripon, and Hawnby on the North Yorks Moors) are discussed in David (1981). The former is confirmed from a specimen collected in 1887, and the latter record may also be correct. However, C. ornithopoda has not been seen east of the Pennines this century.
Many populations of C. ornithopoda lie within SSSIs because of their close association with species-rich, calcareous grasslands which are of high nature conservation value. Communities on the thin parched soils which favour C. ornithopoda generally require only light grazing to maintain their open character, and for most populations the current management regimes are serving the plants well. Some of the larger populations, such as those in Derbyshire, contain many thousands of plants.
C. ornithopoda is widespread in montane areas in Europe, with outlying populations in north-east Anatolia.
Atlas text references
1989. Carex ornithopoda Willd. in Cumberland. Watsonia. 17:437-438.
1980. The distribution of Carex ornithopoda Willd. in Britain. Watsonia. 13:53-54.
1986. Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols.
1982. Sedges of the British Isles. Botanical Society of the British Isles Handbook no. 1, edn 2.
1965. Vergleichende Chorologie der zentraleuropäischen Flora. Volume 1. 2 vols.
1997. Bird’s-foot Sedge (Carex ornithopoda Willd.) in Cumbria. The Carlisle Naturalist. 5:18-23.
1999. British Red Data Books. 1. Vascular plants, edn 3.