Polygonum lapathifolium

Species: Polygonum lapathifolium

English Name: White Smartweed

Chinese Name: 大馬蓼

Family: Polygonaceae

Description:
Herbs annual. Stems erect, 40-90 cm tall, branched, glabrous, subglabrous, or lanose, swollen at nodes. Petiole 2-5 mm, appressed hispidulous; leaf blade with large blackish spot adaxially, lanceolate or broadly lanceolate, 5-15 × 1-3 cm, abaxially nearly glabrous or densely lanose, adaxially nearly glabrous, sometimes densely lanose on both surfaces, base cuneate, margin ciliate, apex acuminate or acute; ocrea brownish, tubular, 1.5-3 cm, membranous, glabrous, apex truncate, not ciliate or rarely shortly ciliate. Inflorescence terminal or axillary, spicate, erect or nodding, 3-8 cm, densely flowered, several spikes aggregated and panicle-like; peduncles glandular; bracts funnel-shaped, margin sparsely shortly ciliate. Perianth pink or white, 4(or 5)-parted; tepals 2.5-3 mm, veins strongly forked, curved downward near apex. Stamens usually 6. Styles 2, connate at base. Achenes included in persistent perianth, black-brown, shiny, broadly ovoid, biconcave, 2-3 mm. Fl. May-Jul, fr. Jun-Oct. 2n = 22.

Photos used under a Creative Commons license

References:

– Wu ZY, Raven PH, Hong DY (eds) (2003). Flora of China, Volume 5: Ulmaceae through Basellaceae. Science Press, Beijing, and Missouri Bot Garden Press, St. Louis