A hemiparasitic annual of damp, open grassy places on sandy soils, often by tracks. It normally occurs in drier dune-slacks and in reclaimed heath-pasture, but is also found on pathsides, rough and scrubby grassland and field-borders, and increasingly in re-seeded amenity grasslands and waste places. It thrives on disturbance. Lowland.
This species has increased northwards and eastwards in Britain, largely through introductions from seed mixtures. Conversely, the re-seeding of old pasture has led to some decline over the same period at inland sites in S.W. England. In Ireland, it appears to be relatively stable in the north, but it has declined significantly in the south-west.
Mediterranean-Atlantic element; widely naturalised outside its native range.
Light (Ellenberg): 7
Moisture (Ellenberg): 7
Reaction (Ellenberg): 7
Nitrogen (Ellenberg): 5
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): 5.1
July Mean Temperature (Celsius): 15.4
Annual Precipitation (mm): 1129
Height (cm): 50
Perennation - primary
Life Form - primary
Clonality - primary
Count of 10km squares in Great Britain: 165
Count of 10km squares in Ireland: 101
Count of 10km squares in the Channel Isles: 11
Atlas Change Index: 0.64
Scarce Atlas Account
Parentucellia viscosa (L.) Caruel
Status: not scarce
A hemiparasitic annual of damp grassy places, this plant usually grows on sandy soils, often along tracksides or in ground which is patchily grazed. Fixed dune grassland in dryish dune slacks is one characteristic habitat; poor pasture reclaimed from dampish heath is another. It sometimes occurs in abundance after disturbance, such as the felling of coniferous forests planted on sand dunes. Associated species include Aira caryophyllea, Carex flacca, Centaurium erythraea, Leontodon saxatilis, Lotus corniculatus, Plantago coronopus, Rhinanthus minor, Vulpia bromoides and Salix repens. It is confined to the lowlands.
It is an annual, reproducing entirely by seed. The British distribution, bounded roughly by the 5°C mean January isotherm, suggests that this species requires a mild winter growing season.
P. viscosa appears to colonise new sites readily, and over much of its British range it is probably more widespread and frequent than formerly. The records suggest some decline in the south-west, particularly inland, perhaps due to re-seeding of old pastures.
It is widespread around the Mediterranean basin, and occurs in the Iberian Peninsula and western France; it reaches its northern limit in Scotland. It is also found in Macaronesia.
M. C. F. Proctor