Persicaria lapathifolia (L.) Delarbre

Plants annual, (0.5-)1-10 dm; roots also sometimes arising from proximal nodes; rhizomes and stolons absent. Stems ascending to erect, simple or branched, scarcely ribbed, glabrous or, rarely, appressed-pubescent distally, sometimes glandular-punctate or stipitate-glandular distally. Leaves: ocrea brownish, cylindric, 4-24(-35) mm, chartaceous, base inflated, margins truncate, eciliate or ciliate with bristles to 1 mm, surface glabrous, rarely strigose, eglandular; petiole 0.1-1.6 cm, usually strigose, sometimes glabrous; blade sometimes with dark triangular or lunate blotch adaxially, narrowly to broadly lanceolate, 4-12(-22) × (0.3-)0.5-4(-6) cm, base tapering to cuneate, margins antrorsely scabrous, apex acuminate, faces strigose on main veins, glabrous or tomentose abaxially, glandular-punctate abaxially. Inflorescences mostly terminal, sometimes also axillary, mostly arching or nodding, usually uninterrupted, 30-80 × 5-12 mm; peduncle 2-25 mm, often stipitate-glandular; ocreolae usually overlapping, margins eciliate or ciliate with bristles to 0.4 mm. Pedicels ascending, 0.5-2.3 mm. Flowers 4-14 per ocreate fascicle, homostylous; perianth greenish white to pink, glabrous, not glandular-punctate or glandular-punctate with punctae mostly on tubes and inner tepals, scarcely accrescent; tepals 4(-5), connate ca. 4-3 their length, obovate to elliptic, 2.5-3 mm, veins prominent, those of 2 or 3 outer tepals prominently bifurcate distally, anchor-shaped, margins entire, apex obtuse to rounded; stamens 5-6, included; anthers pink or red, elliptic; styles 2(-3), connate at bases. Achenes included or apex exserted, brown to black, discoid or, rarely, 3-gonous, 1.5-3.2 × 1.6-3 mm, shiny or dull, smooth. 2n = 22.

It is a temperate and subtropical plant. It grows in wet areas above 1500 m altitude in Papua New Guinea. It grows in wetlands. It grows in Inner Mongolia in China. In Argentina it grows from sea level to 1,000 m above sea level. In Sichuan and Yunnan.

CAUTION: It can damage the skin and is suspected of causing death in cattle. (Often animals forget to cook their food!) The shoots are scalded and then fried with butter, cream, flour or eggs. The seeds can be ground and used to thicken soups. The leaves are slightly sour and chewed as a snack.

Can be grown by seedlings.