416. Chromolaena de Candolle in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 5: 133. 1836.
[Greek chroma, color, and laina, cloak, evidently alluding to the colored phyllaries of some species, including the type]
Guy L. Nesom
Perennials or shrubs (sometimes scandent), 20–250 cm (fibrous-rooted). Stems erect or clambering, sparsely to densely branched. Leaves cauline; opposite [alternate, verticillate]; petiolate or sessile; blades usually 3-nerved from bases, mostly deltate to ovate or elliptic, sometimes linear, margins dentate or lobed, faces glabrous or puberulent to tomentose, sometimes gland-dotted. Heads discoid, in corymbiform to thyrsiform arrays. Involucres cylindric [campanulate to hemispheric], 2–7 mm diam. Phyllaries usually readily falling (at least in fruit), 18–65+ in 4–6+ series, 3–5-nerved, ovate to oblong or lanceolate, unequal (papery or herbaceous). Florets [6–]15–40[–75]; corollas white or purple to blue, lavender, or reddish, throats cylindric (lengths 3–4 times diams.); styles: bases not enlarged, glabrous, branches linear to linear-clavate. Receptacles flat to convex, paleate or epaleate. Cypselae prismatic, (3–)5-ribbed, scabrellous, usually gland-dotted as well; pappi persistent, of ca. 40 barbellate bristles in 1 series. x = 10.
Species ca. 165 (4 in the flora): se, sc United States, Mexico, Central America, South America (especially Brazil).
