A densely tufted perennial herb occurring on dry, rabbit-grazed heaths, sandy roadside banks and, in S. Devon and the Channel Islands, on maritime cliff-tops and ledges. Lowland.
Past confusion between F. longifolia and other glaucous taxa of Festuca, and a consequent lack of reliable historical data, means that changes in distribution remain unclear. Several colonies in Breckland have been lost since the early 1980s. Most surviving populations there, and in Nottinghamshire and Lincolnshire, are small and at risk of being ousted by rank grass or shaded out by trees. Coastal populations are less threatened.
Oceanic Temperate element.
Light (Ellenberg): 8
Moisture (Ellenberg): 3
Reaction (Ellenberg): 5
Nitrogen (Ellenberg): 2
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): 4.8
July Mean Temperature (Celsius): 16.2
Annual Precipitation (mm): 751
Count of 10km squares in Great Britain: 15
Count of 10km squares in Ireland: 0
Count of 10km squares in the Channel Isles: 6
RDB Species Accounts
Festuca longifolia Thuill. (Poaceae)
F. glauca var. caesia (Smith) Howarth
Status in Britain: VULNERABLE.
Status in Europe: Vulnerable? Endemic.
F. longifolia is one of our rarest grasses, found at only a few sites in eastern England. In Breckland, it was formerly a plant of large expanses of open heathland which found space between Calluna vulgaris. In its remaining open areas, its close associates are mostly small and non-aggressive, and it will not tolerate enclosure by tall grasses such as Arrhenatherum elatius. Its most frequent associates include Achillea millefolium, Anthoxanthum odoratum, Carex arenaria, Festuca ovina, Galium verum, Koeleria macrantha, Rumex acetosella and Teesdalia nudicaulis; others include Agrostis capillaris, Allium vineale, Festuca rubra, Holcus mollis and Sedum acre. The soil in Breckland is a coarse sand often with small stones over varying depths of chalk. It is loose, subject to erosion, acid and very low in mineral nutrients. On the borders of Lincolnshire and Nottinghamshire, it grows on sandy soils on roadside verges and adjacent acid heath, in some sites with F. brevipila. In the Channel Islands, F. longifolia is found in crevices and on ledges of cliff-faces and on acid rocks.
F. longifolia is a perennial, densely tufted and entirely glaucous with a blue 'bloom'. To the eye it is entirely glabrous but a lens will sometimes reveal some scabridity below the culm and minute cilia on the auricles. It is grazed by rabbits but is resistant, and in young plants the first growth remains stunted with a culm of less than 6 cm. This plant probably has a long life as old plants expand and coalesce into clumps, especially where it has been grazed.
In Britain, it has been recorded since 1987 from seven sites in the West Suffolk Breckland, two in Lincolnshire, and one in Nottinghamshire. In Breckland, three sites have populations of 20-30 plants, a further three sites hold 100-200 and the largest site (Foxhold Heath), holds more than 2,000 plants. At its largest Lincolnshire site, near Torksey, more than 500 clumps were counted in 1981, but the present size of the population is not known. The Nottinghamshire populations, near Spalford Warren, are very small and vulnerable (D.A.Wood, pers. comm. 1997). At three sites in Breckland there are restrictions of road verge space, another site is shaded by Corylus avellana and, at two others, conifers shade within ten metres of the colonies (they are also subject to human disturbance). With the exception of the largest site, all others in Breckland are at risk. In addition, three have been lost in the past ten years: one from a roadside verge; one from a tumulus where the plants succumbed to rank grass growth in the absence of rabbit-grazing; one ousted by rank grass, and shade cast by an adjacent maturing pine plantation.
The Breckland scene is altering and vast maturing conifer plantations are occupying former heathland which are frequently planted to the road boundary causing a reduction of sunlight to road verges. Rabbit-grazing which formerly maintained the balance of plant competition is now considerably reduced, and many types of Breckland habitats are being overrun by coarse grasses. Populations on road verges are ever vulnerable to damaging activities. British populations, especially perhaps the outlying ones, should be carefully monitored and special conservation measures considered.
This species is endemic to Europe, where it has a very limited distribution, occurring only in England, the Channel Islands (nine sites on Guernsey and one on Sark), and northern and north-central France. Its status in continental Europe seems uncertain, perhaps because of past confusion with other glaucous taxa of Festuca, and it is not listed as a threatened species in Olivier, et al. (1995).
Further information on the taxonomy and morphological characters of F. longifolia is given in Wilkinson & Stace (1991).
P. J. O. Trist and M. J. Wigginton
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
1965. Vergleichende Chorologie der zentraleuropäischen Flora. Volume 1. 2 vols.
1973. Festuca glauca Lam. and its var. caesia (Sm.) K. Richt. Watsonia. 9:257-262.
1999. British Red Data Books. 1. Vascular plants, edn 3.
1989. The taxonomic relationships and typification of Festuca brevipila Tracey and F. lemanii Bastard (Poaceae). Watsonia. 17:289-299.