Common name: Annual Ragweed
Ambrosia artemisiifolia L. APNI*
Description: Annual, shallow-rooted herb to 2 m high.
Leaves lanceolate to ovate, 1–16 cm long, 1–5 cm wide, bipinnately divided, lobes lanceolate to oblong; alternate at base and sometimes opposite above, green to grey-green, finely hairy to ± glabrous.
Male heads yellow-green; female heads few in clusters, with 1 floret. Bracts forming the fruit c. 3 mm long, with a single row of 4–6 spines or teeth, sometimes less or inconspicuous, and a central beak.
Flowering: summer to autumn.
Distribution and occurrence: A weed of roadsides, wasteland and cultivation, occasionally pastures, north from Sydney. Native of N Amer.
NSW subdivisions: *NC, *CC, *SC, *CT
Other Australian states: *Qld *S.A.
Declared Noxious Weed
Text by L. Murray
Taxon concept: Flora of NSW 3 (1992)
APNI* Provides a link to the Australian Plant Name Index (hosted by the Australian National Botanic Gardens) for comprehensive bibliographic data
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