This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
[Actinomeris Nutt. Gen. 2: 181. 1818.] Rough-pubescent, rather coarse, herbs with alternate or opposite, simple, more or less toothed leaves, usually decurrent on the stem and branches, and corymbose, radiate or discoid heads. Involucre small, flattish, of few spreading or recurved narrow bracts. Receptacle convex or conic, becoming globose, chaffy. Ray-flowers neutral, yellow or white, sometimes wanting. Disk-flowers perfect, fertile, embraced by the chaff. Anthers entire at the base. Style-branches of the disk with acute appendages. Achenes flattened, more or less winged, spreading in all directions on the globose receptacle. Pappus of 2 or 3 finally spreading smooth awns, sometimes with 2-3 smaller awns or scales. [Name unexplained.]
Two species, of eastern North America, the following typical.
Coreopsis allemifolia L. Sp. Pl. 909. 1753. Ac inomeris squarrosa Nutt. Gen. 2: 181. 1818. Actinomeris altemifolia DC. Prodr. 5: 575. 1836. Verbesina altemifolia Britton; Kearney, Bull. Torr. Club 20: 485. 1893.
Perennial; stem puberulent or glabrous, narrowly winged, or wingless, simple, or branched near the summit, leafy, 4°-9° high. Leaves oblong-lanceolate or lanceolate, acuminate, serrate, serrulate or entire, rough or roughish on both sides, gradually narrowed to the sessile base, or short-petioled, 4'-12' long, i'-2i' wide, alternate, or the lower opposite and slender-petioled; heads numerous, l'-2' broad, corymbose-paniculate; rays 2-10, yellow; involucre of few lanceolate, at length deflexed bracts; disk globose, yellow; achenes broadly winged or nearly wingless, sparingly pubescent; pappus 2 divergent awns.
In rich soil, New Jersey to Iowa, Kansas, Florida and Louisiana. Winged ironweed. Aug.-Sept.