Annuals (sometimes persisting), (5-)20-50(-100+) cm. Stems usually branching from bases and/or distally, rarely scapiform, usually glabrous proximally, sometimes pilosulous. Cauline leaves (1-)3-9+, proximal mostly lanceolate, margins usually dentate, sometimes pinnately lobed, distal narrowly lanceolate to lance-attenuate, margins entire or with 1-2 lobes near bases. Heads (1-)3-5+ in loose, corymbiform arrays. Calyculi: bractlets 13-16+ in 2-3 series, subulate to filiform, 8-12+ mm. Involucres ± cylindric to campanulate, 17-24+ mm. Phyllaries 16-21+. Florets 50-150+; anthers 2.5-3.5 mm (pollen equatorial diameters mostly 43-47 µm). Cypselae: bodies reddish brown, 4-6 mm, beaks 8-10 mm; pappi 7-10+ mm. 2n = 12.
Caulescent annual or biennial 2-10 dm, commonly minutely hirtellous-puberulent under the heads, otherwise generally glabrous or nearly so; lvs entire to pinnatisect, the basal sometimes much the largest and persistent, to 25 נ6 cm, sometimes deciduous and scarcely larger than the well developed cauline ones; heads several or occasionally solitary; invol 1-2 cm at anthesis; body of the achene 4-5 mm, the filiform, subapically very fragile beak longer, often twice as long; 2n=12. Fields, dry woods, bottomlands, and waste places; Del. and Md. to Ill. and Kans., s. to Fla. and Tex. June-Sept. (Sitilias c.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
My only specimens are from a low, flat fallow field along Big Creek about one and three fourths miles south of Wadesville, Posey County. In this field are small areas where there is no vegetation, called by the land owner salt spots. In this hard, white clay soil several specimens were collected. This species was reported from White County by Heimlich. Since White County has no habitats similar to the one in which I found my specimen, I question the identification. White County is far north of the known range of the species. If Heimlich found it, I believe it must have been introduced. Andrews reported it from Monroe County, but since he preserved no specimen, and since the habitat is lacking and the place is north of the range of the plant, the report is disregarded.