Ambrosia artemisiifolia L.

Common Ragweed

Sp. Pl. 988 (1753) APNI

Taxonomic status:Accepted

Occurrence status:Extinct

Establishment means:Introduced

Erect annual herb to 2 m high, shallow-rooted, non-stoloniferous; stems usually simple, with long spreading hairs. Leaves alternate, sometimes opposite above, lanceolate to ovate in outline, mostly 1–16 cm long and 1–5 cm wide, bipinnate to bipinnatisect with lanceolate or oblong segments mostly 2–4 mm wide, surfaces finely hairy to glabrescent; petiole to 2 cm long. Inflorescences often several together, 3–10 cm long. Male capitula numerous, 2–3 mm diam., yellow-green or white; peduncles c. 1 mm long; florets many, slightly exceeding involucral bracts. Female capitula in small clusters in upper axils; fruiting capitula obovoid, c. 3 mm long, with 4–14 spines with erect or recurved apices, apex with a central beak. Flowers summer and autumn.

Also naturalised WA, Qld, NSW. Native to North America. In Victoria known only by an old collection from Cape Paterson but probably more widespread than this.

Source: Jeanes, J.A. (1999). Asteraceae. In: Walsh, N.G.; Entwisle, T.J. (eds), Flora of Victoria Vol. 4, Cornaceae to Asteraceae. Inkata Press, Melbourne.
Updated by: Val Stajsic, 2018-01-08
Hero image
Distribution map
life Life
kingdom Plantae
phylum Tracheophyta
superorder Asteranae
order Asterales
family Asteraceae
genus Ambrosia
Higher taxa


Source: AVH (2014). Australia's Virtual Herbarium, Council of Heads of Australasian Herbaria, <>. Find Ambrosia artemisiifolia in AVH ; Victorian Biodiversity Atlas, © The State of Victoria, Department of Environment and Primary Industries (published Dec. 2014) Find Ambrosia artemisiifolia in Victorian Biodiversity Atlas
  Bioregion Occurrence status Establishment means
Gippsland Plain extinct introduced

State distribution

Distribution map
Western Australia
South Australia
New South Wales