Polygonum bistorta L., Sp. Pl. 360. 1753; Kitamura, Fl. Afghan. 89. 1960; Webb & Chater in Tutin et al., Fl. Europ. 1: 80. 1964; Cullen & Coode in Davis, Fl. Turkey 2: 272. 1966; Rech. f. & Schiman-Czeika in Rech. f., Fl. Iran. 58: 63. 1968; R.R.Stewart, Ann. Cat. Vasc. Pl. W. Pak. & Kashm. 204. 1972; Polygonum bistortoides Boiss., Diagn. Ser. 1(5): 46. 1844; Persicaria bistorta (L.) Sampaio, Herb. Portug. 41. 1913; Ronse Decr. & Akeroyd in Bot. J. Linn. Soc. 98: 367. 1988.

Perennial herb with thick, stout woody rhizome. Stem simple bearing few to several leaves. Lower leaves large, 40-80 x 10-15 mm, lanceolate, often truncate at the base, borne on winged petiole, upper leaves lax, sessile, glabrous or slightly puberulous, margin of upper and lower leaves revolute to undulate; ochrea c. 30 mm long, oblique, truncate, not fimbriate. Inflorescence terminal into a spike-like head 15-20 x 10 mm densely flowered. Ochreolae obtuse to acute, upper one long, abruptly apiculate. Flowers almost sessile. Perianth 5-partite, tepals c. 3 mm long, pink. Styles 3. Nut triquetrous, shining.

Type: Described from Switzerland, Austria and France, Linn. Herb., 510.3 (LINN).

Distribution: Europe, Siberia, Iraq, Iran and Pakistan (Kurram).

A rare or under-collected species in our area. Known from one gathering from Kurram which seems to be its eastern most limit. Rech. f. & Schiman-Czeika, l.c. rightly pointed out that our plants (including those from Iran and Iraq) differ from typical Bistorta major (Polygonum bistorta) by having smaller inflorescence and smaller perianth and might represent a separate taxon. More material is needed in order to reach any definite conclusion.