A much-branched perennial herb growing from the cracks and mortar crevices of brick and stone walls, on building rubble, rocks, cliffs and steep-sided hedge banks. It prefers dry, sunny, sheltered spots, and is often found in built-up areas or not far from habitation. Lowland.
There appears to have been little change in distribution since the 1962 Atlas, where it was mapped as `all records`. Its frequent occurrence on the walls of abbeys and priories is possibly connected to its use by medieval herbalists as a remedy for urinary disorders.
Submediterranean-Subatlantic element; also in C. Asia.
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.