A tall, rhizomatous perennial herb naturalised on roadsides, by railways and on river banks, waste ground and spoil heaps on a wide range of soil types. Garden throw-outs can be very persistent; the plants are fertile and spread by seed. Lowland.
S. canadensis was introduced into cultivation in Britain in 1648, and it is now very popular in gardens. It was recorded in the wild in 1888 in Oxfordshire, but did not become widespread until 1930. Although formerly confused with S. gigantea, the maps are probably reliable in indicating that S. canadensis is the commoner of the two in S. Britain. It is likely to be increasing.
Native of N. America; widely naturalised in Europe.
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.