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..
Perennial hirsute herbs, with alternate pinnatifid leaves, and corymbose slender-peduncled rather large heads of both tubular and radiate yellow flowers. Involucre hemispheric, its bracts imbricated in 2 or 3 series, the outer linear, loose, hirsute, ciliate, the inner oval or obovate, concave, appressed, subtending the ray-flowers. Receptacle flat, chaffy, the chaff subtending and partly enclosing the disk-flowers. Rays 8-10, pistillate, fertile. Disk-flowers about as many, tubular, perfect, sterile, the corolla 5-toothed. Anthers minutely 2-dentate at the base. Style of the tubular flowers undivided. Achenes obovate, compressed, not winged, 1-ribbed on each face. Pappus a persistent irregularly cleft crown. [Named for Dr. Geo. Engelmann, 1809-1884, botanist, of St. Louis.]
A monotypic genus of the south-central United States.
E. pinnatifida T. & G. Fl. N. A. 2: 283. 1841.
Stem usually branched above, 1°-3° high. Basal leaves slender-petioled, 4'-8' long, their lobes lanceolate or oblong, dentate or entire, obtuse or acutish; upper leaves smaller, sessile, less divided, the uppermost sometimes entire, or with a pair of basal lobes; heads usually numerous, about 1' broad; peduncles 1'-5' long; outer bracts of the involucre somewhat in 2 series, the first linear, the second broadened at the base.
In dry soil, Kansas to Colorado, Louisiana, Arizona and North Mexico. Reported as found along railroads in western Missouri. May-Aug.