This procumbent low shrub is found on upland heaths and moorlands, often over well-drained gravelly or rocky ground, and on ravine sides. It sometimes grows in heathy grasslands on limestone, as in the Burren. From sea level in W. Ireland and Ardtoe (Westerness) to c. 710 m (Rannoch Moor, Mid Perth) and reportedly at 915 m in Inverness-shire.
A procumbent perennial herb found as a well-naturalised garden escape on walls, buildings and stony banks, often in damp, shaded sites. Lowland.
This low-growing perennial calcicole is found in open mountain grassland and on N.-facing Carboniferous limestone cliffs in the Ben Bulben range in Co. Sligo, at altitudes of 400-600 m.
A rhizomatous perennial herb which persisted for several years on Wimbledon Common (Surrey) and grows amongst Pteridium aquilinum on Guernsey. Lowland.
An annual or biennial herb which usually grows in sparsely vegetated, well-drained sites associated with Carboniferous limestone, including peaty depressions on flat slabs, peat in cracks and hollows in limestone pavement, and in open, bryophyte-rich tufaceous flushes. Its seed appears to have considerable longevity. Found only at moderate altitudes between 295 m at Selside and 410 m at Dawson Close (both Mid-W. Yorks.).
This annual, biennial or perennial herb grows on base-rich substrates over limestone, serpentine and other basic rocks, occurring on rocky knolls, screes, river gravels, fell-field, and occasionally on exposed summit ridges. From c. 15 m on Unst (Shetland) to 650 m on Beinn Sgulaird (Main Argyll).
A winter- or rarely summer-annual of dry, usually shallow, neutral to basic soils. It is found in a wide range of open habitats, including rock outcrops, cliffs, screes, walls, spoil heaps from mines and in quarries, railway ballast, waysides and arable field margins. Generally lowland, but reaching at least 610 m at Melmerby Fell (Cumberland).
A winter- or rarely summer-annual of dry, open sites in similar habitats to those of subsp. serpyllifolia and sometimes growing with it. However, there may be a stronger preference for cultivated and waste ground, old walls and quarries (Grose, 1957). It is also found in bare places in calcareous grassland, on roadsides and railway tracks. 0?500 m (Teesdale, N.W. Yorks.).
A winter- or rarely summer-annual of dry, open sites, such as disturbed ground and ant-hills on chalk and limestone downs, sand dunes and other sandy and gravelly places, rabbit warrens, arable fields, roadsides, railways, quarries, rock ledges, walls, spoil-tips and waste ground. 0?610 m (Melmerby Fell, Cumberland).
A well-branched, slightly spiny annual, occasionally grown in gardens and found as a casual on rubbish tips and waste ground. It also occurs as a grain and wool alien. Lowland.