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..
[Brickellia Ell. Bot. S. C. & Ga. 2: 200. 1824.] Herbs or shrubs, with opposite or alternate leaves, and discoid heads of white yellowish or pink flowers, in panicles or cymes, or rarely solitary. Involucre campanulate or oblong, its bracts striate, imbricated in several series, the exterior ones successively smaller. Receptacle flat or convex, naked. Corolla regular. 5-lobed. Anthers obtuse at the base. Style-branches long, obtuse. Achenes 10-striate or 10-ribbed. Pappus a single row of numerous rough or serrate bristles. [Greek, sheath-flower.]
A genus of about 70 species. Besides the following, some 45 others occur in the southern and western United States. Type species: Coleosanthus Cavanillesii Cass.
Eupatorium grandiflorum Hook. Fl. Bor.
Phil. Soc. (II.) 7: 287. 1841. Coleosanthus grandiflorus Kuntze, Rev.
Erect, glabrous or puberulent, much branched, 2°'-3° high. Leaves slender-petioled, deltoid-ovate, cordate at the base, acuminate at the apex, coarsely crenate-dentate, 2-4' long, 1-2' wide; petioles shorter than the leaves; inflorescence cymose-paniculate; heads short-peduncled, 6"-7" long; peduncles pubescent; involucre campanulate, 30-45-flowered, the outer bracts ovate, pubescent, usually abruptly acuminate or subulate-tipped, the inner linear, glabrous, striate, obtuse or acute; pappus bristles scabrous.
Montana to Wyoming, Missouri, New Mexico, Washington and Arizona. Aug-Sept. Tassel-flower.