Helianthus annuus L.

Erect annual herb, with stout taproot. Stems scabrid, not branched, 0.4- c. 2 m tall. Lower and mid cauline lvs hispidulous, petiolate, ovate- elliptic to ovate-triangular, acute to acuminate, obtuse or truncate to cordate at base, serrate, 6–20–(30) cm long; upper cauline lvs similar to lower, but uppermost alternate, smaller and narrower. Capitula (8)–10–20–(30) cm diam., solitary. Involucral bracts in 2–3 rows, moderately to densely scabrescent, ciliate, ovate to ovate-triangular, aristate, c. 3–6 × (0.8)–1.5–2 cm. Receptacle ± flat; scales membranous, the larger with dark ciliate apices. Ray florets (15)–20–50; disc florets numerous, brownish yellow. Achenes oblong-obovoid, narrowed to base, hairy, 10–15 mm long; pappus 0.

[From: Webb et al. (1988) Flora of New Zealand. Volume 4.]

Flowering: Jan.–Mar.