Common name: Mexican Sunflower
Tithonia diversifolia (Hemsl.) A.Gray APNI*
Description: Perennial herb, 2.5–5 m high; stem strongly striate, hairy at first then glabrescent.
Leaves ovate in outline, 7–33 cm long, 7–22 cm wide, unlobed to 3–5-lobed, margins toothed, apex acuminate, base decurrent on petiole; petiole to 6 cm long, auriculate at base.
Peduncles up to 24 cm long; heads 3–5 cm diam.; receptacle scales 1–2 cm long; involucral bracts graduated, oblong to ovate, 3- or 4-seriate. Ligules yellow, linear, 5–7 cm long, apex 3-toothed; ray achenes in 1 row, white to yellow. Disc achenes black or mottled, 4-angled, 5–6 mm long; pappus of fused scales and 2 ± equal awns, 5 mm long.
Distribution and occurrence: Common weed of roadsides, embankments and wasteland, north from Coffs Harbour district. Native of C Amer.
NSW subdivisions: *NC
Other Australian states: *Qld
Text by L. Murray
Taxon concept: Flora of NSW 3 (1992)
APNI* Provides a link to the Australian Plant Name Index (hosted by the Australian National Botanic Gardens) for comprehensive bibliographic data
***The AVH map option provides a detailed interactive Australia wide distribution map drawn from collections held by all major Australian herbaria participating in the Australian Virtual Herbarium project.