Perennials, 50-100+ cm. Stems (from short rhizomes, green) single, branched distally, puberulent throughout. Leaves opposite (± vertical); petiolate (petioles 10-30 mm); blades ± 3-nerved distal to bases, deltate to rhombic, 25-80 × 20-60 mm, bases broadly cuneate, margins usually serrate (teeth uneven), sometimes crenate, apices acute, faces glabrate to sparsely puberulent, gland-dotted. Heads in corymbiform arrays. Phyllaries 8-12 in 2-3 series, elliptic to oblong, 1.5-5 × 0.8-1 mm, apices acute to acuminate, abaxial faces puberulent, gland-dotted. Florets 5; corollas 3.5-4 mm. Cypselae 1.2-1.5 mm; pappi of 20-35 bristles 3.5-4.5 mm. 2n = 20. Flowering Jul-Sep. Moist or wet, low, often saline places; 0-10+ m; Fla.