Conyza canadensis, (L.) Cronq.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1976, Flora Europaea. Volume 4. Plantaginaceae to Compositae (and Rubiaceae), Cambridge University Press : 120

1. C. canadensis (L.) Cronq. , Bull. Torrey Bot. Club 70: 632 (1943)

( Erigeron canadensis L. ).

Annual 10-150 cm, patenthirsute. Leaves numerous, narrow, the lower up to 10 x 1 cm, oblanceolate, petiolate, often deciduous, the others linear, at least the upper sessile. Capitula less than 1 cm wide, generally numerous, in a long, paniculate inflorescence with a single axis. Involucre 3-4 mm, glabrous or nearly so. Female florets usually 25-45; ligules 0-5-1 mm, equalling or slightly exceeding the style and pappus. 2« =18. Cultivated ground and waste places. Naturalized almost throughout Europe. [All except Fa Hb Is Rs (N) Sb.] (North America.)