This annual or biennial herb occurs on freely-draining skeletal or sandy soils on waste ground by the sea, including dockyards, roadsides and car parks. Lowland.
An annual of saltmarshes, sea-walls, muddy shingle, brackish grazing pastures and the base of coastal cliffs. Inland, it is a local colonist of the margins of saline sludge lagoons, and also occurs beside salt-treated roads. Generally lowland, but reaching 520 m on a roadside at Holme Moss (Cheshire).
The natural habitats of this perennial herb are strictly maritime. It is found in saltmarshes, on muddy beaches, banks and low cliffs, in tidally inundated dune-slacks, and on the margins of saline ditches in coastal grazing marshes. In saltmarshes, it is generally found at lower elevations than S. marina. Inland, it occurs very occasionally as a colonist of salt-treated roadsides. Lowland.
An annual or biennial herb, typically occurring in open habitats on free-draining acidic sands and gravels. Habitats include heaths, commons, tracks (particularly forestry tracks in W. Scotland), quarries, gravel- and sand-pits, railway yards and waste ground. It occasionally grows on stabilised shingle and sand dunes. It is tolerant of trampling. Generally lowland, but recorded at over 560 m on Deadwater Fell (S. Northumb.).
A perennial herb of maritime rocks and cliffs, growing in crevices, on ledges and on friable rock surfaces, sometimes in guano-enriched sites near sea-bird colonies. It also grows in short cliff-top grassland and on the masonry of piers and walls near the sea. It is indifferent to soil reaction. Lowland.