• Scientific Name: Polygonum criopolitanum Hance
• Ref: Ann. Sci. Nat., Bot., sér. 5. 5:238. 1866
• Synonym: Persicaria criopolitana (Hance) Migo
• Chinese Common Name: 蓼子草 liǎozi∙cǎo
• Family: Polygonaceae
• Genus: Polygonum
• Distribution: In sand by riversides, wet ditches; sea level to 900 m. Anhui, Fujian, Guangdong, Guangxi, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Zhejiang.
• Photo: 12/03/2016, Lin’an, Zhejiang

Herbs annual. Stems tufted, prostrate, 10-15 cm tall, rooting from nodes, diffusely branched from base, long strigose, sparsely glandular hairy. Petiole very short or nearly absent; leaf blade narrowly lanceolate or lanceolate, 1-3 cm × 3-8 mm, both surfaces strigose, base narrowly cuneate, margin ciliate with glandular hairs, apex acute; ocrea tubular, membranous, densely strigose, apex truncate, long ciliate. Inflorescence terminal, capitate; peduncle densely glandular hairy; bracts ovate, 2-2.5 mm, densely strigose, margin long ciliate, each 1-flowered. Pedicels longer than bracts, densely glandular hairy, articulate at apex. Perianth purplish red, 5-parted; tepals ovate, 3-4 mm. Stamens 5; anthers purple. Styles 2, connate at middle. Achenes included in persistent perianth, shiny, ellipsoid, biconvex, ca. 2.5 mm. Fl. Jul-Nov, fr. Aug-Dec. (Flora of China)