Helianthus annuus

Scabrous to hispid, erect annual or biennial herb 0.5–2 m high, taprooted. Leaves opposite below, alternate above, ovate to triangular, mostly 3–20 cm long and 2–12 cm wide, apex apiculate, base cordate or truncate, margins entire to serrate; petiole 1–10 cm long. Capitula 1–few, 3–20 cm diam., turned to one side or nodding; involucral bracts 3-seriate, ovate to lanceolate, 15–25 mm long, acuminate, scabrous, ciliate; receptacle scales 3-lobed, 8–12 mm long, membranous. Ray florets numerous, bright yellow, ligules mostly 2–3 cm long; disc florets numerous, brownish. Cypselas obovate, 5–10 mm long, broad-cuneate, 4-angled, black with grey streaks, finely appressed-pubescent; pappus of 2 minute, early-caducous scales. Flowers mostly Nov.–Jun.