Description: Annual and perennial herbs; stems erect.
Leaves opposite below, often alternate above, sessile or petiolate, simple, entire to lobed.
Heads large, terminal and solitary or few in a cyme, pedunculate; involucral bracts herbaceous, 3-seriate; receptacle flat or convex, with non-persistent scales. Ray florets in 1 row, female, fertile or sterile, ligulate, yellow. Disc florets bisexual, fertile, tubular, 5-toothed, brownish, purple, or yellowish.
Achenes compressed; pappus absent or of 2 or more non-persistent scale-like awns, rarely small persistent scales also present.
Distribution and occurrence: World: c. 67 species, North & South America. Australia: 3 species (naturalized), all mainland States. Sunflowers
Text by L. Murray
| ||Key to the species|| |
|1||Leaves scabrous or hispid, ligules more than 12 mm long||2|
|Leaves glabrous, ligules c. 10 mm long||Helianthus ciliaris|
|2||Leaves alternate||Helianthus annuus|
|Midstem leaves opposite|
Back to 1