in T. Mori, Enum. Pl. Corea, 131. 1922.
Plants annual, 3–8 dm; roots not also arising from proximal nodes. Stems ascending to erect, ribbed or obscurely so, glabrous or glandular-pubescent distally; prickles 1–1.5 mm. Leaves: ocrea brownish, cylindric, 8–14 mm, chartaceous, base inflated or not, without prickles, margins truncate, ciliate with bristles 2–4 mm, surface with appressed bristles along veins; petiole 0.5–1.5 cm; blade lanceolate to narrowly elliptic, 5–12.5 × 1.5–3.5 cm, base acute, margins entire, antrorsely ciliate, apex acute-acuminate, rarely obtuse, faces glabrous or pubescent and, usually, with antrorse prickles along midvein abaxially and adaxially. Inflorescences racemelike, uninterrupted or interrupted proximally, 20–45 × 5–10 mm; peduncle 20–40 mm, usually stipitate-glandular at least proximally; ocreolae usually overlapping, sometimes not overlapping proximally, margins eciliate. Pedicels mostly ascending, 2–3 mm. Flowers 2–4 per ocreate fascicle; perianth pale green, often tinged red, glabrous, accrescent, not becoming blue and fleshy in fruit; tepals 5, connate 1/4–1/3 their length, petaloid, elliptic to broadly elliptic, 3–4 mm, apex obtuse; stamens 8, filaments distinct, free; anthers pink, ovate; styles 2, connate to middle. Achenes included, black, biconvex, 2.5–3 × 2.3–2.8 mm, dull, rugose.
Phenology: Flowering Jul–Sep.
Habitat: Cultivated fields
Elevation: 300-400 m
Introduced; Ill., Iowa, Minn., e Asia (n China), e Asia (Japan), e Asia (Korea), e Asia (Manchuria)
Persicaria bungeana is a weed of soybean fields (R. N. Andersen et al. 1985). It is not known how or when it was introduced into the midwestern United States.
"/2" is not declared as a valid unit of measurement for this property.