A tall perennial of ledges inaccessible to grazing animals on moist, predominantly N.-facing acidic rocks, often where there is late snow-lie. From 700 m in Glen Doll (Angus) to 1090 m on Lochnagar (S. Aberdeen), but formerly at 530 m in Glen Canness (Angus).
This is one of our rarest mountain plants and only four sites are extant. The perennial threat is from trampling or grazing by deer and other animals. It is an outbreeding species with several colonies perhaps comprising single clones with poor seed production.
European Boreal-montane element; a woodland and sub-montane meadow species across much of its European range.
Light (Ellenberg): 7
Moisture (Ellenberg): 6
Reaction (Ellenberg): 6
Nitrogen (Ellenberg): 6
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): -1.3
July Mean Temperature (Celsius): 10.5
Annual Precipitation (mm): 1375
Height (cm): 130
Perennation - primary
Life Form - primary
Clonality - primary
Comment on Clonality
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
Cicerbita alpina (L.) Wallroth (Asteraceae)
Alpine Blue sow-thistle, Bliochdan Gorm Ailpeach
Status in Britain: VULNERABLE. WCA Schedule 8.
Status in Europe: Not threatened.
C. alpina is one of the largest and leafiest mountain plants in Britain. When in fresh flower it is a stately, attractive plant but, despite predominantly occurring in humid sites sheltered from strong winds, often soon succumbs to the mountain weather and wears a scorched and battered look. Most of its colonies lie on broad ledges or sloping rocky gullies with a good depth of soil at altitudes between 530 and 1,090 metres. The parent rock is always acidic, but there is probably some base-enrichment from irrigation which brings the soil pH to 4.8-5.9 (McVean and Ratcliffe 1962). These ledges often carry snow well into early summer. A characteristic associate is Athyrium distentifolium, and other frequent associates in what is usually a fairly lush ledge flora are Alchemilla glabra, Deschampsia cespitosa, Dryopteris species, Luzula sylvatica, Rumex acetosa and Solidago virgaurea.
This tall, rhizomatous perennial usually grows in clumps of several square metres, with hollow reddish, erect flowering stems about a metre high rising above a 'mattress' of succulent, broadly sagittate leaves. Because of its general appearance, one colony was known to climbers as 'the potato patch'. The deep blue-violet racemes of flowers appear in late July and last until early September, with bumble-bees the chief pollinators. Seed-set appears to be very irregular, and seed often inviable. Some, possibly all, populations may be clones, with outbreeding prevented by the isolation of one population from the next..
This species was first discovered by George Don in 1801, on one of his many ascents of Lochnagar. Later in the century it was found in Glen Callater, Caenlochan, Glen Canness and Glen Clova, and this portion of the eastern Highlands in Aberdeenshire and Angus remains its known range. About fifteen locations have been identified since first recorded, but it has been lost from many, leaving only four extant. The four colonies produced a total of about 600 flowering spikes in 1995, compared with about 500 in 1979-1983.
In living memory, C. alpina has been confined to steep corries and cliffs out of reach of sheep and deer. Early Floras indicate that the plant once grew by the side of burns on more accessible ground, which suggests that its present isolation was caused by overgrazing. Suitably large, moist, sheltered ledges are few and far between, and this limitation of habitat may alone explain the rarity of the plant in the eastern Highlands. It seems poorly adapted to mountain conditions and may be an example of a former sub-montane species surviving only in sub-optimal habitats at atypical elevations.
The Scottish populations appear to have long-term stability, though undergo short-term change. They also sometimes suffer temporary damage from rock falls, drought and from occasional deliberate cutting. The seldom visited and declining population in Glen Canness succumbed to drought and overgrazing in 1976, but a healthy population was rediscovered in Glen Clova by A.G.Payne in 1979 after a 30-year interval. It has been suggested that 'lost vitality' may threaten the survival of the species, but this is not certain.
Outside Britain, C. alpina is a common submontane plant in Scandinavia and in the main central European mountain ranges. Here it occurs most typically in moist conditions near the tree line as a member of a tall-herb flora with Trollius europaeus and Geranium sylvaticum in birch and pine forest on the more basic soils. In Scandinavia it also occurs in submontane meadows and on roadsides.
Marren, et al. (1986) provide further details of the ecology and distribution of C. alpina.
B. G. Hogarth and P. R. Marren.
Atlas text references
1986. Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols.
1986. The past and present status of Cicerbita alpina (L.) Wallr. in Britain. Watsonia. 16:131-142.
1992. Vergleichende Chorologie der zentraleuropäischen Flora. Volume 3. 2 vols.
1999. British Red Data Books. 1. Vascular plants, edn 3.