Perennials, (10–)20–120 cm, colonial or cespitose; usually long-rhizomatous, sometimes with branched caudices. Stems 1–3+, erect (straight to ± flexuous), glabrate to sparsely hirsute or strigillose, especially distally. Leaves thin, margins coarsely, sharply serrate to crenate-serrate or serrulate, ciliate to scabrous, apices acute or acuminate, mucronulate, abaxial faces glabrate to sparsely hirsute, midveins usually densely hirsute, sometimes glabrous, adaxial glabrous or glabrate to scabrellous; basal usually withering by flowering (sometimes persistent on small plants), long-petiolate (petioles slightly winged, sheathing, ciliate), blades ovate, (24–)40–120(–270) × 15–70 mm, bases usually shallowly cordate, sometimes rounded; proximal cauline often withering by flowering, winged-petiolate, blades ovate to oblanceolate or lanceolate, (24–)60–150 × (10–)20–60 mm, reduced distally, bases subcordate to cuneate; distal sessile or sometimes subsessile (petioles widely-winged), blades lance-ovate to linear-lanceolate or linear, 18–75 × (2–)5–25 mm, bases cuneate, sometimes ± clasping, margins serrulate or entire. Heads [(6–)13–50(–100+)] in open, paniculiform arrays, branches ascending. Peduncles 0.2–1.5+ cm, unequal, reduced distally, ± hirsutulous, bracts 0–4, subulate or linear. Involucres campanulate, (4–)5–6.5 mm. Phyllaries in 4–5 series, narrowly oblong-lanceolate to oblong-oblanceolate or linear-oblanceolate (innermost), ± unequal, bases indurate 1/3–2/3, margins narrowly scarious, erose, hyaline or infrequently purplish, sparsely ciliolate, green zones lanceolate to linear-lanceolate or linear, apices acuminate to long-acuminate, faces glabrous. Ray florets (12–)14–20; corollas pale to deep blue or bluish purple, laminae (8.3–)10–15 × 1–2.3 mm. Disc florets 14–25(–29); corollas yellow becoming reddish purple, 4.3–6.4 mm, tubes shorter than funnelform throats, lobes narrowly triangular, 0.5–1.1 mm. Cypselae yellowish white, obovoid, compressed, 1–2 mm, 5–6-nerved, faces glabrate to sparsely strigillose; pappi white to pinkish, 3–6 mm. 2n = 48.
