Plants of South Eastern New South Wales
Ambrosia artemisiifolia
Common name
Annual ragweed, Common ragweed
Family
Asteraceae
Where found
Woodland, pastures, roadsides, wasteland and cultivation, and along streams. Coastal north from near Batemans Bay. Sydney region as far inland as Richmond.
Notes
Introduced annual herb to 2 m high. Stems cylindrical, almost hairless to rough hairy, reddish or brownish-green. Leaves initially forming a basal rosette, then opposite each other near the plant base and sometimes alternating up the stems higher up the stems, 1–16 cm long, 10–70 mm wide, green to grey-green, hairy with fine hairs to more or less hairless, fern-like, deeply lobed or compound. Male and female flowers on the same plant. Male flower heads 2–3 mm in diameter, cream, yellowish, yellow-green or pale green to white, hemispherical, with 10-100 florets in each head. Male flower heads in spike-like clusters up to 20 cm long. Female flower heads with 1 tiny floret, in clusters of 1-7 flower heads. Flowering: summer to early winter.
General Biosecurity Duty all NSW.
PlantNET description: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Ambrosia~artemisiifolia (accessed 3 January, 2021)
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