Pilosella flagellaris subsp. bicapitata
An endemic perennial herb of grassy limestone rocky outcrops, heathy granulitic gneiss and feldspathic rocky sea-banks in three localities in Shetland, where it was first described in 1962. Lowland.
There has been no change in the distribution of this subspecies at the 10-km scale. However, two of its three localities are accessible to sheep, and the increased grazing in recent years has suppressed flowering and might have reduced the populations. The occurrence of this endemic subspecies in Shetland at such a distance from native populations of subsp. flagellaris in C. & S. Europe presents a fascinating problem in plant distribution.
RDB Species Accounts
NOTE: The account below is for the sub-species. Closely related species and sub-species may have separate accounts listed elsewhere in the Online New Atlas
Pilosella flagellaris (Willd.) P.D.Sell & C.West ssp. bicapitata P.D.Sell & C.West (Asteraceae)
Shetland mouse-ear hawkweed
Status in Britain: VULNERABLE. ENDEMIC.
This plant of rocky slopes, pastures and outcrops is endemic to Shetland, and was first described in 1962. It is very localised, being known from only three sites (Scott 1968) despite its ability to grow in a variety of habitats. It grows amongst limestone rocks in rocky pastures in many discontinuous occurrences along 3 km of the White Ness peninsula, particularly on the west side, where it is associated with such species as Anthyllis vulneraria, Polygala vulgaris and Primula vulgaris (W.Scott, pers. comm.). It is, however, rarely able to flower there in the heavily grazed sward, except in one or two rocky places inaccessible to sheep. At West Burrafirth, it occurs on a large heathy rocky knoll of granulitic gneiss with Calluna vulgaris and Solidago virgaurea. Flowering was formerly more frequent there, but is now very limited because of increased grazing. The other known site, at Ronas Voe, is on feldspathic rock adjoining granite on steep rocky sea-banks, where it grows with rare Hieracium species (Scott & Palmer 1987). There are at least 120 plants at Ronas Voe, in three colonies, and flowering is more likely at this site because of the lack of grazing.
Where allowed to flower, P. flagellaris ssp. bicapitata will produce flowers and achenes abundantly. This is the only Pilosella known on Shetland: P. officinarum, common on Orkney, appears to be entirely absent.
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.