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..
Erect or diffuse, branching, annual, or perennial, strong-scented, more or less glandular herbs, with opposite, mostly finely dissected leaves, and small peduncled heads of both tubular and radiate yellow flowers. Involucre campanulate or nearly hemispheric, its bracts in I series, united into a cup, with small additional outer ones. Receptacle flat, pubescent. Ray-flowers pistillate, the rays short. Disk-flowers perfect, their corollas 5-toothed. Anthers entire or minutely 2-toothed at the base. Style-branches of the disk-flowers hirsute, apiculate. Achenes narrowly obpyramidal, 3-5-angled, striate. Pappus of about 10 scales, parted to beyond the middle into numerous capillary, bristle-like segments. [In honor of J. von Boeber, a Russian botanist, died 1820.]
About 3 species, natives of the central United States and of Mexico, the following typical.
Tagetes papposa Vent. Hort. Cels. pl. 36. 1800. Boebera chrysanthemoides Willd. Sp. Pl. 3: 2125. 1804. Dysodia chrysanthemoides Lag. Gen. et Sp. Nov. 29. 1816. D. papposa Hitchc. Trans. St. Louis Acad. 5: 503. 1891. B. papposa Rydb.; Britton, Manual 1012. 1901.
Annual, very leafy, glabrous or finely pubescent, gland-dotted, much branched, 6'- 18' high, the branches diffuse or erect. Leaves sessile, or short-petioled, 1/2' - 1 1/2' long, pinnately parted into linear or slightly spatulate, sharply serrate or incised segments; heads numerous, short-peduncled, 3"- 5" broad; involucre campanulate, of 8-10 appressed, oblong, obtuse, green or purplish, glabrous or ciliate bracts, with several narrow shorter outer ones; rays few, not longer than the width of the disk; receptacle and achenes pubescent.
Along streams and roadsides, Ohio to Minnesota, Montana, Louisiana, Mexico and Arizona. Occasionally found as a weed in waste places in the Eastern and Middle States, and in Ontario. Prairie-dogweed. July-Oct.