Biennials, 40-150 cm. Leaves: basal simple (5-20 mm wide) or 1(-2)-pinnate, 5-25 cm, lobes (3-)5-20+ × (1-)2-8+ mm; cauline 15-50. Heads (20-)40-100 per stem. Peduncles 1-5 cm. Phyllaries white to yellowish, 5-15 × 2-8 mm. Ray florets 0. Disc florets 20-80; corollas whitish, 3-5.5 mm, tubes 2-3 mm, throats funnelform, 1-3 mm, lengths ± 1 times lobes. Cypselae 3-5 mm, ± hirtellous; pappi of 14-18 scales 0.1-1 mm. Morphologic distinctions between varieties of Hymenopappus scabiosaeus as treated by B. L. Turner (1956) fail for some specimens.
Taprooted biennial 3-7 dm, floccose-tomentose and partly glabrate, becoming more villous-puberulent above; lvs pinnatifid or the larger bipinnatifid, the lower 8-25 cm including the short petiole, 3-12 cm wide, or occasionally narrower and entire, the middle and upper generally smaller, often scattered and progressively reduced, at least some always pinnatifid; heads in an open-corymbiform infl, the disk 7-12 mm wide at anthesis; invol 7-10 mm; lobes of the disk- cor ca as long as the throat; pappus-scales hyaline, 1 mm or less; 2n=34. Prairies and dry, open woods; Tex. to s. Neb., e. irregularly to n. Ind., S.C., and Fla. May. (H. carolinensis) Ours is var. scabiosaeus.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.