Plants perennial, 3-20 dm; roots also sometimes arising from proximal nodes; rhizomes present, stolons sometimes present. Stems ascending, usually branched proximally, scarcely ribbed, glabrous, glandular-punctate; branches sometimes creeping and rooting at nodes. Leaves: ocrea light brown, cylindric, 10-15 mm, chartaceous, base inflated, margins truncate, ciliate with bristles 3-12 mm, surface strigose, glandular-punctate; petiole 0.2-2 cm, glandular-punctate; blade without dark triangular or lunate blotch adaxially, lanceolate to elliptic-lanceolate, 4-20 × 2-4.5 cm, base tapered, margins antrorsely strigose, apex acute to acuminate, faces glabrous or main veins scabrous, glandular-punctate. Inflorescences terminal and axillary, erect, uninterrupted, 20-80 × 5-10 mm; peduncle 5-40 mm, glandular-punctate; ocreolae usually overlapping, margins eciliate or proximal ones sometimes ciliate with bristles to 1 mm. Pedicels ascending to spreading, 2-5 mm. Flowers 2-4 per ocreate fascicle, homostylous; perianth greenish proximally, white distally, glandular-punctate with punctae ± uniformly distributed, slightly accrescent; tepals 5, connate ca. 3 their length, obovate, 3.2-4.2 mm, veins prominent or not, not anchor-shaped, margins entire, apex obtuse to rounded; stamens 6-8, included; anthers pink or red, elliptic; styles 3, connate proximally. Achenes included or apex exserted, dark brown to brownish black, 3-gonous, 2.7-3.6 × 2-2.5 mm, shiny, smooth. Flowering Jul-Oct. Peaty shores, often in water on coastal plain or near coast; 0-1500 m; N.S., Ont., Que.; Conn., Del., Fla., Ind., Ky., Maine, Md., Mass., Mich., Mo., N.H., N.J., N.Y., Ohio, Pa., R.I., Tex., Va.; West Indies; Central America; South America. Persicaria robustior often is synonymized with P. punctata.