A perennial herb of shallow soil in open, grassy habitats on limestone sea-cliffs and rocky slopes, cliff-top grassland and wind-pruned heath overlying limestone. It is a poor competitor, and is usually intolerant of heavy grazing, although in Pembrokeshire it is found in low-growing, sheep-grazed, cliff-top grassland and heath. It seems to be self-incompatible and some small populations appear to represent single, self-sterile clones. Lowland.
Native (change -0.10). The distribution is of A. linosyris stable, but some populations are very small.
European Temperate element, with a continental distribution in W. Europe; it reaches its northern limit on Öland and Gotland.
RDB Species Accounts
Aster linosyris (L.) Bernh. (Asteraceae)
Linosyris vulgaris DC., Crinitaria linosyris (L.) Less.
Goldilocks aster, Gold y Môr
Status in Britain: LOWER RISK - Near Threatened.
Status in Europe: Not threatened.
A. linosyris is restricted to a few coastal localities in western Britain, where it occurs on limestone sea-cliffs and rocky slopes, and in cliff-top grassland and heath overlying limestone. It is confined to more or less open communities, typically in a discontinuous tussocky turf on shallow soil, or as isolated clumps. A wide variety of associated maritime and limestone herbs include Anthyllis vulneraria, Crithmum maritimum, Daucus carota, Festuca rubra, Plantago coronopus and Scabiosa columbaria. At some sites it occurs with other rare species, including Helianthemum apenninum and H. canum. Many of its populations are on inaccessible cliff ledges. In Pembrokeshire, colonies occur in low-growing sheep-grazed grassland and maritime heath on cliff-tops, with Calluna vulgaris, Danthonia decumbens, Erica cinerea and Succisa pratensis.
It is a woody, long-lived perennial, and appears to be a sexually-outcrossing species. Flowers appear in late summer and are usually at their best in September. Seed is freely produced, but the production of fertile seed may sometimes be sparse or absent in some colonies (Jones 1994). The relative importance of sexual and vegetative reproduction, conditions of seedling establishment, and genetic exchange between colonies are unknown. It is a poor competitor, unable to compete successfully in closed turf, and is intolerant of heavy grazing by sheep or rabbits.
There are about eight localities in Devon, Somerset, Glamorgan, Pembrokeshire, Caernarvonshire and Westmorland. Pembrokeshire holds much the largest populations, large stands several metres across occurring in two main areas of cliff-top between Stackpole and Linney Head. In 1988, the population there was estimated to be about 7,000 plants (Morgan 1989e). By contrast, some colonies are small and vulnerable: for example, at Humphrey Head only a single clump survives (I.Slater, pers. comm. 1997). Casual occurrences, for instance on ballast tips and railways, have been only rarely reported.
At some sites, colonies are under threat from overgrowth of scrub, usually Prunus spinosa, but locally also by bramble or bracken. In these areas, some grazing is desirable to check the growth of these invasive species. Local disturbance of the vegetation may be beneficial in providing open areas in the turf; indeed at one locality the plant appears to grow preferentially along cliff-top sheep-walks. Excessive trampling is damaging, however, and because of it some populations have declined. Other potential local threats include quarrying.
The species has a continental distribution in Europe, being common in the south and east and becoming rarer in the north and west, but reaching southern Sweden. Though normally occurring on steep limestone slopes or outcrops, it is also found on the chalk in north-western France, and its absence from the English chalk is, therefore, noteworthy. It may be that it failed to find suitable habitats on this soft limestone during the post-glacial forest maximum (Pigott & Walters 1954).
M. J. Wigginton