Helianthus tuberosus L.

Erect perennial herb, with short rhizomes and well developed tubers. Stems hispid, not or sparingly branched, up to c. 3 m tall, dying back to tubers in winter. Lower and mid cauline lvs hispidulous, petiolate, narrow-ovate to deltoid or rhomboid, acuminate, obtuse at base, irregularly serrate, (8)–20–25 cm long, often with short shoots and reduced lvs in axils; upper cauline lvs similar to lower but alternate and uppermost shortly petiolate, smaller and narrower. Capitula 5–8 cm diam., in loose corymbs of 2–6. Involucral bracts in 2–3 rows, sparsely hairy and ciliate, narrow-lanceolate, acute, 8–15 × 2–4 mm. Receptacle convex; scales membranous, the larger with darker ciliate apices. Ray florets 10–15; disc florets numerous, yellow or tinged brown. Achenes narrow-obovoid, hairy toward apex, 4–6 mm long; pappus of 2–5 laciniate scales.

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

Flowering: Apr.