Perennials, to 125+ cm; fibrous rooted (arising from stout rhizomes or woody caudices). Leaves 5-40 × 3-15+ cm, pinnatifid to pinnate, lobes 3-9, narrowly lanceolate to ovate, 1-15 × 0.2-3.5 cm, faces strigose, gland-dotted. Heads mostly 1-12, held well beyond leaves. Peduncles 3-27+ cm (ribs tan, prominent). Phyllaries 10-15, outer linear, 3-15 × 1-3 mm, inner lanceolate-ovate, 3-6 × 0.7-3 mm. Paleae 1.2-5 × 1-1.8 mm, resin glands linear to oblanceolate, 2-3.3 mm. Ray florets 6-15; corollas yellow, 2.5-3.8 mm, tubes ca. 1-3 mm, hirsute, laminae linear-elliptic to oblong-oblanceolate, 16-60 × 4-15 mm. Discs ellipsoid to globular or ovoid, 10-25 × 10-18 mm. Disc florets 100-200+; corollas greenish yellow, often purplish distally, 2.5-3.8 mm; style branches ca. 1.8 mm, proximal 1/2 stigmatic, apices subulate. Cypselae linear-oblanceoloid, 2-4 × 1-2.3 mm, margins usually glabrous, sometimes adaxial ciliate; pappi 0 or of 1-2 toothlike projections. 2n = 28. Flowering May-Oct. Prairies, woodland openings and borders, limestone outcrops; 10-300 m; Ont.; Ala., Ark., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Mass., Mich., Minn., Miss., Mo., Nebr., N.Y., Ohio, Okla., S.Dak., Tenn., Vt., Wis.
From Flora of Indiana (1940) by Charles C. Deam
Infrequent to frequent in all parts of the state, although it may be rare in the Lower Wabash Bottoms. It is generally found in dry or gravelly soil along streams and roadsides and in prairie habitats, where it is rarely absent. It usually forms large colonies and sometimes becomes a weed.
Fibrous-rooted from a stout, woody rhizome or sometimes a short caudex, 4-12 dm, ±hirsute, or the stem strigose above; lower lvs long-petioled, the upper short-petioled or sessile; lf-segments lanceolate, acute, coarsely toothed or entire; heads usually several, naked-pedunculate; disk ellipsoid-globular, 1-2 cm, 1-1.6 times as long as thick, much shorter than the rays, these pale yellow, (2.5-)3-6 cm, spreading or often reflexed; style-appendages elongate, acuminate; achenes smooth; pappus none; 2n=28. Prairies, old fields, and dry woods, often on limestone; s. Ont. to Minn. and S.D., s. to Tenn., Ga., w. Fla., La., and Okla., and adventive e. to Vt. and Mass. June-Aug.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.