A perennial herb of species-rich, locally flushed calcareous grassland, and on base-rich ledges and rocky outcrops. Montane, from 650 m (Ben Vrackie, E. Perth) to 770 m (Creig an Dail Bheag, S. Aberdeen).
A. alpinus is still extant in all four of its known localities, though populations on unstable rocks and crags are threatened by trampling and erosion, whilst colonies in grassland are suffering reduced flowering and seed set due to intensive grazing by sheep and deer.
Circumpolar Arctic-montane element.
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Light (Ellenberg): 9
Moisture (Ellenberg): 4
Reaction (Ellenberg): 6
Nitrogen (Ellenberg): 2
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): -0.9
July Mean Temperature (Celsius): 11
Annual Precipitation (mm): 1275
Height (cm): 30
Perennation - primary
Life Form - primary
Clonality - primary
Count of 10km squares in Great Britain: 4
Count of 10km squares in Ireland: 0
Count of 10km squares in the Channel Isles: 0
Plantatt Conservation Status
RDB Species Accounts
Astragalus alpinus L. (Fabaceae)
Alpine milk-vetch, Bliochd-pheasair Ailpeach
Status in Britain: VULNERABLE.
Status in Europe: Not threatened.
The largest colonies of A. alpinus occur in species-rich, locally flushed calcicolous grassland, which forms a patchy mosaic with communities of Calluna vulgaris, Erica tetralix and Vaccinium myrtillus. It also grows on the margins of flushes, but is rarely present in areas dominated by the dwarf shrubs. A wide range of associates includes Carex pulicaris, Deschampsia cespitosa, Festuca ovina, Galium verum, Persicaria vivipara, Saussurea alpina, Sibbaldia procumbens and Thymus polytrichus. It also grows on base-rich ledges and rocky outcrops with such species as Carex rupestris, Dryas octopetala, Erigeron borealis and Silene acaulis.
It is a small herbaceous perennial. Flowers normally appear between mid-June and mid-July, but like many mountain plants, flowering time is greatly influenced by climate. The number of inflorescences may also vary from year to year. For instance, in a monitored colony in Caenlochan between 1986 and 1992, numbers ranged from 29 to 120. It is not known, however, whether this is indicative of a natural cycle or merely reflects variable levels of grazing.
In Britain, A. alpinus is known from only four sites in the eastern Scottish Highlands, three of which hold several disjunct populations. In total, there are about twenty discrete colonies, most of which form patches of only 1-15 square metres. However, the largest (of more than 10,000 plants) covers some 120 x 30 metres, in which A. alpinus may attain a cover of 50% or more.
At some sites, A. alpinus grows on very unstable rocks and soil which cannot withstand much trampling. Indeed significant damage to ledges and crags has already happened in certainly one station, and plants have been lost from the eroded rocks. This damage may be partly attributed to sheep but, in at least one site, visiting botanists have added to it. Plants are grazed by sheep and deer, and this may be the main reason for the lack of flowers and seed-pods which is often reported. The survival of the whole of the smallest population may be particularly uncertain: monitoring over the past few years has shown that very few if any flowers remain ungrazed, and no seed pods are produced.
A. alpinus is widespread in northern Europe and on central European mountain ranges, including the Alps, Pyrenees and Carpathians. It ranges through temperate Asia, and occurs in North America and Greenland.
M. J. Wigginton