Scientific Name:
Erigeron canadensis L.
  • Conyza canadensis (L.) Cronquist (1943)
  • = Erigeron pusillus Nutt. – as pusillum
  • Conyza canadensis var. pusilla (Nutt.) Cronquist
  • = Conyza parva Cronquist (1943)

Erect annual to biennial herb, up to c. 1 m tall. Stems ridged, sparsely to moderately hispid, becoming less hairy below. Cauline lvs oblanceolate, flat, apetiolate and cuneate, acute, mostly remotely serrate, rarely entire, sparsely to moderately hispid on both surfaces, usually prominently and densely ciliate, 30–70 × 3–8 mm; uppermost lvs smaller, often linear. Infl. a leafy panicle with dominant main axis. Capitula 1–3 mm diam.; receptacle usually smooth, rarely with short flanges between pits. Inner involucral bracts linear, green, glabrous or with 1–2 hairs on midrib, 2.5–4 mm long; outer bracts glabrous, or with a few hairs on midrib. Outer florets with evident ligules 0.5–1 mm long, white. Achenes obovoid-cylindric, sparsely hairy, 1–1.3 mm long; pappus hairs cream to fawn.

[From: Webb et al. (1988) Flora of New Zealand. Volume 4. as Conyza canadensis (L.) Cronquist]


Flowering: Dec.–Mar.

2006: Asteridae (in part): Asteraceae, part 2. Flora of North America Editorial Committee (ed.) Flora of North America. Vol. 20. Oxford University Press, New York. [as Conyza canadensis (L.) Cronquist; Conyza canadensis var. pusilla (Nutt.) Cronquist; Conyza parva Cronquist]
Flora of North America Editorial Committee (ed.) 1993: Flora of North America. New York and Oxford. [as Conyza canadensis (L.) Cronquist; Conyza canadensis var. pusilla (Nutt.) Cronquist; Conyza parva Cronquist; Erigeron pusillus Nutt.]
Nesom, G.L. 2008: Classification of subtribe Conyzinae (Asteraceae: Astereae). Lundellia 11: 8–38.
Shi Zhu; Chen Yilin; Chen Yousheng; Lin Yourun; Liu Shangwu; Ge Xuejun; Gao Tiangang; Zhu Shixin; Liu Ying; Yang Qiner; Humphries, C.J.; von Raab-Straube, E.; Gilbert, M.G.; Nordenstam, B.; Kilian, N.; Brouillet, L.; Illarionova, I.D.; Hind, D.J.N.; Jeffrey, C.; Bayer, R.J.; Kirschner, J.; Greuter, W.; Anderberg, A.A.; Semple, J.C.; Štěpánek, J.; Freire, S.E.; Martins, L.; Koyama, H.; Kawahara, T.; Vincent, L.; Sukhorukov, A.P.; Mavrodiev, E.V.; Gottschlich, G. 2011: Asteraceae. Wu, C.Y.; Raven, P.H.; Hong, D.Y. (ed.) Flora of China. Vol. 20-21. Science Press, Beijing, and Missouri Botanical Garden Press, St. Louis.