64. Polygonum capitatum Buchanan-Hamilton ex D. Don, Prodr. Fl. Nepal. 73. 1825.
头花蓼 tou hua liao
Cephalophilon capitatum (Buchanan-Hamilton ex D. Don) Tzvelev; Persicaria capitata (Buchanan-Hamilton ex D. Don) H. Gross.
Herbs perennial. Stems creeping, tufted, ligneous at base, sparsely glandular hairy or nearly glabrous, much branched, rooting from nodes, internodes shorter than leaf blades; branchlet suberect, angulate, sparsely glandular hairy. Petiole 2-3 mm, sometimes auriculate at base; leaf blade sometimes with a large blackish spot adaxially, ovate or elliptic, 1.5-3 × 1-2.5 cm, both surfaces glandular hairy, base cuneate, margin entire and glandular hairy, apex acute; ocrea tubular, 5-8 mm, membranous, sparsely glandular hairy, apex truncate, ciliate. Inflorescence terminal, capitate, solitary or geminate, 6-10 mm in diam.; peduncle glandular hairy; bracts narrowly ovate, membranous. Pedicel very short. Perianth pinkish, 5-parted; tepals elliptic, 2-3 mm. Stamens 8, included. Styles 3, connate to below middle, equaling perianth; stigmas capitate. Achenes included in persistent perianth, black-brown, slightly shiny, narrowly ovoid, trigonous, 1.5-2 mm, densely punctate. Fl. Jun-Sep, fr. Aug-Oct.
Mountain slopes, shaded places in valleys; 600-3500 m. Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangxi, Sichuan, Taiwan, Xizang, Yunnan [Bhutan, N India, Malaysia, Myanmar, Nepal, Sikkim, Sri Lanka, Thailand, Vietnam].
This species is used medicinally, and is cultivated as an ornamental in other parts of the world (e.g., in Australia).
Newly naturalized in Taiwan (see Hsu, T. W., S. M. Ku & C. I. Peng. Taiwania 49(3): 183. 2004).