This annual of disturbed, usually fertile ground is found on roadsides, waste ground, tracks and in field gateways, and in arable crops. Generally lowland, but reaching 845 m on Great Dun Fell (Westmorland).
Although cultivated in 1781, this species was first recorded in the wild in Britain as an escape from Kew Gardens in 1871 and in Ireland in 1894, and it became one of the fastest spreading plants in the 20th century. Its spread was aided by the transport of seeds on tyres and footwear. The distribution is now stable.
Probably native of N. & S. Asia and perhaps adjacent parts of N. America; in the 19th and 20th centuries it spread to boreal and temperate zones throughout the N. hemisphere.
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
1988. Comparative Plant Ecology.
1986. Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols.
1992. Vergleichende Chorologie der zentraleuropäischen Flora. Volume 3. 2 vols.
1964. Weeds & Aliens, edn 2.