An annual or biennial herb of damp, often winter-wet soils, occurring on cultivated and waste ground, and frequently found in gardens and lawns, by paths and roadsides and on rubbish tips. Lowland.
C. didymus reached Britain in the early 18th century, being recorded from the wild by 1778. It is now frequent in urban and industrial areas, and is still spreading into rural areas where it is widespread but scattered.
A widespread alien in W. Europe, N. America and the S. hemisphere; origin uncertain, often cited as S. America.
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.
Atlas text references
1986. Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols.
Jalas & Suominen (1996)
1991. Crucifers of Great Britain and Ireland. Botanical Society of the British Isles Handbook no. 6.