Perennials, 40–80(–100) cm. Stems erect, lax, minutely pilose. Leaves opposite; petioles 7–15(–22) mm; blades narrowly deltate to rhombic, 2–6(–7) × 1.5–4 cm, (usually subcoriaceous) bases usually cuneate, sometimes truncate to slightly subcordate, margins usually coarsely serrate or incised, sometimes crenate to subentire, apices acute to acuminate, abaxial faces glabrous or hairy on veins. Heads clustered. Peduncles 2–10 mm, sparsely puberulent. Involucres 2.5–4 mm. Phyllaries: apices acute, abaxial faces puberulent to villous-puberulent. Corollas white, lobes glabrous or sparsely short-hirtellous. Cypselae usually finely hirtellous-strigose on distal 1/3, sometimes glabrous. 2n = 34.
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