Common name: Common Sunflower
Helianthus annuus L. APNI*
Description: Annual or biennial herb with taproot, 1–2 m high; stems often branching towards apex.
Leaves ovate to ± cordate, 3–20 cm long, 1–10 cm wide, margins entire to toothed, surfaces hispid to scabrous; upper leaves alternate, smaller and narrower.
Heads 1 or few per plant, solitary and nodding, on hairy peduncles; heads usually 3–10 cm diam.; involucral bracts ovate to lanceolate, acuminate, scabrous, ciliate; receptacle scales 3-toothed, membranous. Ray florets bright yellow; ligules 2–3 c. or more long. Disc florets numerous, brownish.
Achenes broad-cuneate, flattened, 5–10 mm long, black with grey streaks, finely pubescent; pappus absent.
Flowering: throughout year.
Distribution and occurrence: Grows on roadsides and disturbed sites, widespread. Native of N Amer.
NSW subdivisions: *NC, *CC, *ST, *NWS, *CWS, *NWP, *SWP, *NFWP, *SFWP
Other Australian states: *Qld *Vic. *W.A. *S.A. *N.T.
Widely cultivated for the oil extracted from the seeds, and sometimes grown as an ornamental. The cultivated forms have much larger heads than the naturalized plants.
Text by L. Murray
Taxon concept: Flora of NSW 3 (1992)
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