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/ 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. Flowering Jul-Sep. Cultivated fields; 300-400 m; introduced; Ill., Iowa, Minn.; e Asia (n China, Japan, Korea, Manchuria). Persicariabungeana 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.
Erect, taprooted annual to 7 dm, with the aspect of sect. Persicaria; stem beset with scattered short, stout, recurved prickles, otherwise largely glabrous except for the conspicuously stipitate-glandular branches of the infl; lvs lanceolate or narrowly elliptic, 5-15 נ1-2.5 cm, tapering to the short petiole, rough-strigose along the midrib and main veins at least beneath, otherwise largely glabrous; ocrea coarsely antrorse-strigose, but with few or no cilia around the top; racemes lax, rather short; mature perianth 3.5-4 mm, constricted at the base; achenes plump, dark, dull, 2.5-3 mm long and wide. Native of e. Asia, locally intr. as a weed in Minn., and to be expected elsewhere.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.