Conyza sumatrensis is an annual herb probably native to South America, but widely naturalised in tropical and subtropical regions, and regarded as an invasive weed in many places. In the British Isles it is known as Guernsey fleabane. In certain countries the plant has started to exhibit resistance to herbicides. In Britain, of the alien British Conyza species, this is the second most abundant (after C. canadensis) and is typically found in London and the South East of England.It was first recorded in London by Brian Wurzell in 1984,and noted in France at Saint-Sozy (Dordogne) in 2006.