Polygonum chinense

Species: Polygonum chinense

English Name: Chinese Knotweed

Chinese Name: 火炭母

Family: Polygonaceae

Herbs perennial. Rhizomes stout. Stems erect, 70-100 cm tall, ligneous at base, much branched, striate, glabrous or retrorsely hispid. Petiole 1-2 cm, usually auriculate at base, upper leaves subsessile; leaf blade ovate, elliptic, or lanceolate, 4-16 × 1.5-8 cm, both surfaces glabrous or hispid, abaxially sometimes pubescent along veins, base truncate or broadly cordate, margin entire, apex shortly acuminate; ocrea tubular, 1.5-2.5 cm, membranous, glabrous, much veined, apex oblique, not ciliate. Inflorescence terminal or axillary, capitate, 3-5 mm, usually several capitula aggregated and panicle-like; peduncle densely glandular hairy; bracts broadly ovate, each 1-3-flowered. Perianth white or pinkish, 5-parted; tepals ovate, accrescent in fruit, becoming blue-black, fleshy. Stamens 8, included. Styles 3, connate to below middle. Achenes included in persistent perianth, black, opaque, broadly ovoid, trigonous, 3-4 mm. Fl. Jul-Nov, fr. Jul-Dec. 2n = 22*.

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– 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