Polygonum plebeium

Species: Polygonum plebeium

English Name: Axil-flowered Knotweed

Chinese Name: 腋花蓼

Family: Polygonaceae

Description:
Herbs annual. Stems prostrate, 10-40 cm tall, much branched from base, usually internodes shorter than leaves. Petiole very short or nearly absent; leaf blade narrowly elliptic or oblanceolate, 5-15 × 2-4 mm, both surfaces with conspicuous midvein and inconspicuous lateral veins, base narrowly cuneate, margin entire, apex obtuse or acute; ocrea white, 2.5-3 mm, membranous, apex lacerate. Flowers 3-6, in axillary fascicles; bracts membranous. Pedicels shorter than bracts, articulate at middle. Perianth green, margin white or pinkish, 5-parted; tepals narrowly elliptic, 1-1.5 mm, abaxially with prominent veins. Stamens 5; filaments included, slightly dilated at base. Styles 3, rarely 2, very short; stigmas capitate. Achenes included in persistent perianth, black-brown, shiny, broadly ovoid, trigonous or biconvex, 1.5-2 mm, smooth. Fl. May-Aug, fr. Jun-Sep. 2n = 20.

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