Perennials, 10-100(-120) cm, cespitose; with short, thick, woody caudices, tangled or sometimes cormoid, and long rhizomes. Stems 1-5+, ascending to erect (often stout, light to dark brown), sparsely to densely scabroso-hirsute to cinereo-puberulent, or villous distally. Leaves (light to dark green) thick and often stiff (margins flat, sometimes undulate), scabrous; basal early deciduous, subpetiolate (petioles winged, sheathing), blades spatulate to obovate, 30-70 × 10-30 mm, bases cuneate, margins entire to ± serrulate, scabrous, apices acute to rounded, faces scabroso-hirsute; proximal cauline sessile, blades usually ovate to lanceolate, rarely spatulate, (20-)30-70(-100) × 10-30(-40) mm, reduced distally, bases strongly cordate-clasping to auriculate-amplexicaul (broadened below constriction), apices acute, faces (grayish green) rugulose, hairy (abaxial inconspicuously veined, adaxial reticulately veined, hairier along veins); distal sessile, blades narrowly to broadly ovate, 15-35 × 4-13 mm, much reduced on branches, bases strongly cordate-clasping to auriculate-amplexicaul, apices usually acute, sometimes obtuse, mucronate to white-spinulose, faces scabrous, sometimes sparsely to moderately stipitate-glandular. Heads in paniculiform arrays, branches divaricate (heads 1-5+ per branch), terminal shoot often not flowering. Peduncles stiffly ascending, slender, 2-10(-15) cm, scabroso-hirsute to cinereo-puberulent, bracts appressed to spreading, linear, 1-5 mm, grading into phyllaries. Involucres campanulate, 5.5-12 mm. Phyllaries in 4-7(-8) series, appressed or often slightly recurved-spreading or squarrose, ovate-lanceolate to linear, strongly unequal, bases (tan) ± indurate in proximal 1 / 3 - 1 / 2 , margins hyaline, erose, distally scabroso-ciliolate to ciliolate, green zones diamond-shaped, in distal 1 / 5 - 1 / 3 , apices (outer) obtuse to acute, appressed to squarrose, (inner) acuminate, often purplish red, faces strigillose or cinereo-puberulent abaxially and near tip adaxially, sometimes moderately stipitate-glandular distally. Ray florets 12-24+; corollas light lavender-violet to mauve, rarely white to pinkish, laminae 10-18(-20) × 1-3 mm. Disc florets 20-50; corollas yellow, cream, or white turning purple, (4.5-)5.5-7.5 mm, tubes shorter than narrowly funnelform throats, lobes triangular, 0.5-1 mm (glabrous or lobes thinly puberulent).
Plants with a short caudex, sometimes with creeping rhizomes as well; stems rather slender and brittle, 2-15 dm, shortly and loosely hairy; lvs ±hairy or scabrous, at least beneath, sessile and conspicuously cordate-clasping, broadly ovate to oblong, entire, 2.5-15 נ0.8-4.5 cm, the lower soon deciduous; heads few to rather numerous in an open, divaricately branched infl; invol 5-9 mm, its bracts well imbricate, mostly acute, ±glandular or short-hairy or both; rays 15-25 (-30), blue (pink), 8-15 mm; achenes shortly sericeous; 2n=10, 20. Woods and dry, open places; Mass. and s. N.H. to s. Mich. and Kans., s. to Fla. and Tex. Four vars.:
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.