7. Bistorta Adans., Fam. 2: 277. 1763; Hara in Hara et al., Enum. Fl. Pl. Nepal 3: 173. 1982; Grierson & D.G.Long, Fl. Bhutan 1 (1): 166. 1983; Munshi & Javeid, Syst. Stud. Polygon. Kashm. Himal. 58. 1986.
Polygonum sect. Bistorta (Adans.) D. Don, Fl. Nepal. 69. 1825; Hook. f., Fl. Brit. Ind. 1: 31. 1886; Kom., Fl. URSS 5: 672. 1936; Schiman-Czeika & Rech. f. in Rech.f., Fl. Iran. 56: 62. 1968; Bhopal & Chaudhri in Pak. Syst. 1: 79. 1977; Polygonum L. sect. Persicaria subsect. Bistorta (Adans.) Benth. & Hook. Gen. Pl. 3: 98. 1880.
Perennial rhizomatous herbs, ± shrubby at the base with thick root stocks, stem simple or branched, branches erect or prostrate with erect leafy scapes. Leaves broad or narrow, usually with narrow revolute margin, sometimes ± undulate or crisp-crenate; ochrea tubular, thin, membranous, brownish, without cilia. Inflorescence spiciform racemes, spikes compact, uninterrupted, eglandular. Bract scarious, oval or lanceolate thin, membranaceous, open, neither tubular nor truncate, never ciliate. Perianth 4-5-parted, not enlarged in fruit. Stamens (4-) 5-8 (-10). Ovary usually trigonous; styles 2-3, long, free or connate at the base; stigma simple, very small. Nuts trigonous or biconvex.
A genus with c. 50 species, distributed in North America, Europe and Asia. Represented in Pakistan by 7 or 8 species.
