Argentine fleabane

Erigeron bonariensis, the Argentine or hairy fleabane, is an annual to short-lived perennial herb of the Asteraceae family, most likely native to South America and now naturalised as a cosmopolitan weed across the warm-temperate and subtropical world. It grows erect to about seventy-five centimetres, with a stout, hairy, branching stem that often forks above the middle into several long, ascending flowering branches. The alternate leaves are blue-green to grey-green, lanceolate, with wavy margins and stiff hairs concentrated at the tips and along the midrib. From summer into autumn the plant bears numerous small, cylindrical flowerheads about a centimetre long in open, leafy panicles, each head with a few short, inconspicuous whitish ray florets and a centre of yellow disc florets. The achenes are tipped with a tawny pappus and are easily borne on the wind.