Polygonum nepalense Meisner, Monogr. Polyg., 84, plate 7, fig. 2. 1826

Plants annual, 3-5 dm; roots also often arising from proximal nodes. Stems decumbent to as-cending, glabrous except for fleshy, retrorse, whitish hairs at nodes. Leaves: ocrea brownish or hyaline, cylindric to funnelform, 4-10 mm, chartaceous, base inflated or not, margins oblique, eciliate, surface glabrous or with bristlelike hairs proximally; petiole 0.1-3 cm, winged to base, leaves sometimes sessile; blade ovate-deltate, 1.5-5 × 1-4 cm, base rounded to truncate, margins glabrous or scabrous, apex acute, faces pilose and glandular-punctate abaxially, glabrous adaxially. Inflorescences terminal and axillary, 5-10 × 5-10 mm; peduncle 2-20 mm, apex stipitate-glandular; ocreolae overlapping, margins eciliate. Pedicels mostly ascending, 0.1-1 mm, flowers sometimes sessile. Flowers 1-2 per ocreate fascicle; perianth white to pink or lavender, urceolate, glabrous, scarcely accrescent; tepals 4(-5), oblong to broadly elliptic, 2.5-3 mm, apex acute to obtuse; stamens (5-)8, filaments distinct, free; anthers purplish black, elliptic; styles 2, connate proximally. Achenes included, dark brown to black, biconvex, 1.5-2 × 1-1.5 mm, dull, minutely punctate.

Flowering Jul-Oct. Disturbed sites, gravel bars in lowland zone; 0-900 m; introduced; B.C.; Conn., Fla., Mass., N.Y., Pa.; Asia; introduced also in Europe, Africa.