Heliopsis

Perennials [annuals], 30–150 cm. Stems erect or trailing, branched from bases or ± throughout. Leaves cauline; opposite; petiolate; blades ± 3-nerved from bases, deltate or ovate to lanceolate, bases ± cuneate to subtruncate, margins serrate or coarsely toothed, faces glabrous or hairy. Heads radiate [discoid], borne singly. Involucres turbinate to hemispheric, 8–14 mm diam. Phyllaries persistent, 12–20 in 2–3 series (ovate or oblong, ± equal, outer more foliaceous than inner). Receptacles convex to conic, paleate (paleae tardily falling, yellowish, conduplicate, becoming chartaceous). Ray florets [0] 5–20, pistillate, fertile; corollas yellow to orange (laminae persistent, sessile, becoming papery). Disc florets 30–150+, bisexual, fertile; corollas yellow or brown to purple, tubes much shorter than narrowly cylindric throats, lobes 5, deltate. Cypselae (brown to black-brown) subterete or obscurely 3(ray)- or 4(disc)-angled (not winged); pappi 0, or persistent, coroniform (each a laciniate crown plus 1–3 toothlike scales). x = 14.

Distribution

North America, Mexico, Central America, South America (to Bolivia).

Discussion

Species ca. 18 (3 in the flora).

Most species of Heliopsis are known only from Mexico.

Selected References

Fisher, T. R. 1957. Taxonomy of the genus Heliopsis (Compositae). Ohio J. Sci. 57: 171–191.

Lower Taxa

Heliopsis gracilis, Heliopsis helianthoides, Heliopsis parvifolia

Key

1	Aerial stems 1–2+ (from creeping rhizomes 4–10+ cm × 1–2 mm, rhizome internodes ca. 20+ mm); heads 1–3(–5); rays 6–8(–13)	Heliopsis gracilis
1	Aerial stems 1–10+ (from ± erect caudices, or from creeping rhizomes to 4 cm × 2–6 mm, rhizome internodes 2–10 mm); heads 1–15+; rays 9–18	> 2
2	Leaf blades (1.5–)3–6 × 0.8–3 cm, faces sparsely pubescent to glabrescent; peduncles (6–)15–30 cm; cypselae rugulose to subtuberculate	Heliopsis parvifolia
2	Leaf blades 6–12(–15) × 2.5–6(–12) cm, faces glabrous, pubescent, or scabrous; peduncles 9–25 cm; cypselae smooth	Heliopsis helianthoides