Cyclachaena

Fresenius

Index Seminum (Frankfurt) 1836: 4. 1838.

Etymology: Greek cyclo -, circular, and Latin achenium, achene allusion uncertain, perhaps to the ring of cypselae in each fruiting head
Treatment appears in FNA Volume 21. Treatment on page 28. Mentioned on page 9, 25.

Annuals, 30–120(–200) cm. Stems erect, strictly, if at all, branched. Leaves cauline; mostly opposite (distal sometimes alternate); petiolate; blades (3–5-nerved) ± deltate, ovate, or rhombic (proximal 1–3 pairs, often 3–5-lobed), margins usually toothed, faces densely to sparsely scabrellous to strigillose (abaxial often canescent), both usually gland-dotted. Heads ± disciform, in (± ebracteate) paniculiform arrays. Involucres turbinate to hemispheric, 3–5+ mm diam. Phyllaries persistent, 10–12+ in 2+ series, distinct, outer 5 herbaceous, inner scarious to membranous. Receptacles convex to conic; paleae spatulate to linear, ± membranous, sometimes 0. Pistillate florets 5; corollas whitish, tubular, or 0. Functionally staminate florets 5–10(–20+); corollas whitish, funnelform, lobes 5, erect (filaments connate, anthers distinct). Cypselae plumply obovoid to obcompressed, finely striate, sparsely strigillose or hispidulous distally, little, if at all, gland-dotted; pappi 0. x = 18.

Distribution

North America, introduced in Europe.

Discussion

Species 1.

Selected References

None.

... more about "Cyclachaena"
John L. Strother +
Fresenius +
North America +  and introduced in Europe. +
Greek cyclo -, circular, and Latin achenium, achene +  and allusion uncertain, perhaps to the ring of cypselae in each fruiting head +
Index Seminum (Frankfurt) +
Undefined (tribe Undefined) subtribe Ambrosieae +  and Undefined (tribe Undefined) subtribe Iveae +
Cyclachaena +
Asteraceae (tribe Heliantheae) subtribe Ambrosiinae +