Conyza sumatrensis

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 the United Kingdom, among the non-native species of Conyza found in Britain, this species ranks as the second most prevalent, following C. canadensis. It is predominantly observed in London and the South East of England. The species was first documented in London by Brian Wurzell in 1984. Additionally, it was recorded in Saint-Sozy, Dordogne, France, in 2006.