Pilosella peleteriana

Pilosella peleteriana (Mérat) F. Schultz & Schultz Bip. (Asteraceae)

Shaggy mouse-ear hawkweed

Status in Britain: VULNERABLE. (all subspecies)

Status in Europe: Not threatened. Endemic.

This perennial hawkweed is known in few locations in Britain, with recent records from Dorset, the Isle of Wight and Montgomeryshire. It is, however, generally the commonest Pilosella in the Channel Islands. Three sub-taxa are distinguished, currently at subspecies level, though varietal status might be more appropriate (Stace 1991).

P. peleteriana ssp. peleteriana occurs only in Dorset and the Isle of Wight, though was formerly also in Kent. It is a plant of chalk soils, with one known locality on limestone on Portland. It occurs on south-facing, steep, and thus well-drained slopes with undistinguished calcicolous associates including Carex flacca, Helianthemum nummularium, Leontodon hispidus, Plantago media, Sanguisorba minor and Thymus polytrichus. It often grows on the edges of paths or terracettes, where drainage is at its sharpest. In the Channel Islands it is far more widespread, and grows on soils overlying granite, particularly on coastal cliffs.

P. peleteriana ssp. subpeleteriana is known only from Craig Breidden in Montgomeryshire, growing there on shallow, drought-prone basic soils overlying dolerite. Populations occur mainly on the dry rock shelves at the south-western end of the hill, with smaller colonies on the northern part. It also grows freely on quarry waste, spreading by rooting stolons. In cultivation, it is attractive to slugs which, in spring, keep the plants well in check and might destroy them entirely if not controlled (R. Woods, pers. comm.). It is possible that in natural habitats such predation could be a factor controlling its spread to moister habitats from the dry outcrops where slugs are scarce.

P. peleteriana ssp. tenuiscapa, characterised by its narrower leaves and smaller flowering heads, seems more elusive and has been much neglected by botanists in recent years. It has been recorded, and may still occur, on the borders of Derbyshire and Staffordshire (in both counties) and perhaps in Yorkshire, but is likely to have gone from Devon (L.Spalton, pers. comm.). Pugsley (1948) considered this plant much more common than ssp. peleteriana in Jersey, though Le Sueur (1984) has not differentiated them.

Like P. officinarum, the single head of yellow flowers is borne on a stem arising from a rosette of lanceolate leaves, but the rare species is more robust, with larger flower heads, short thick stolons often ending in a rosette of large crowded leaves, which themselves are often notably shaggy with long hairs. It is an altogether more striking plant. It spreads by stolons from a thick long-lasting rootstock. In garden conditions the stolons (of ssp. peleteriana) can elongate by up to 10 cm a year (D.Pearman, pers. obs.), but probably spread less rapidly in the wild. Its main threat on the south coast is from the spread of Brachypodium pinnatum, which now covers vast areas of ungrazed turf, restricting P. peleteriana to areas grazed by rabbits or kept short by human activities, such as trampling on path edges. The main populations on Craig Breidden seem reasonably secure, providing quarrying does not encroach. 

P. peleteriana occurs on the western and southern coasts of Europe. Its ecology relative to that of P. officinarum is not clearly understood, but the two species are known to hybridise.

D. A. Pearman and M. J. Wigginton