18. Persicaria nepalensis (Meisn.) H. Gross in Bot. Jahrb. 49: 277. 1913; Hara in Fl. East. Himal. 72. 1966, in Hara et al. l.c. 177; Grierson & D.G.Long, Fl. Bhutan 1: 164. 1983; Munshi & Javeid, Syst. Stud.Polygon. Kashm. Himal. 77. 1986. (Fig.7, A-D).
Polygonum nepalense Meisn., Monog. Polyg. 84, pl. 7, f. 2. 1826; Hook.f., Fl. Brit. Ind. 5: 41. 1886; Rech.f. & Schiman-Czeika in Rech.f., Fl. Iran. 56: 55. 1968; R. R. Stewart, Ann. Cat. Vasc. Pl. W. Pak. & Kashm. 207. 1972; Bhopal & Chaudhri in Pak. Syst. 1: 72. 1977; Polygonum punctatum Buch.-Ham. ex D. Don, Prodr. Fl. Nep. 73. 1825 non Elliot 1817, nec Raffin. 1820; ; Polygonum alatum Buch.-Ham. ex Spreng. Syst. Veg. Cur. Post 154. 1827; P. perforatum Meisn., l.c. 83; Persicaria alata (Buch.-Ham. ex D. Don) Nakai, Fl. Qualpaert Isl. 40. 1914; Polygonum alatum var. nepalense (Meisn.) Hook. f., l.c. 42; P. perforatum var. laevigatum Meisn. in Wall. Pl. As. Rar. 3: 59. 1832.
Ascending-erect, 20-30 (-50) cm high, glabrous - glandular hairy, annual herb. Stem simple or branched with striate internodes. Leaves 1.8-5 x 0.5-3 cm, lower ones often ± rhomboid with a rotundate base, upper ones petiolate, cordate to amplexicaul with a auricled base, petiole 1 cm long, slightly to moderately winged. Ochrea tubular-truncate, glabrous - glandular or hairy at base 4-5 mm long, brownish. Inflorescence terminal corymbose head, head 6-7 mm in diameter, substanded by an involucral leaf. Involucral leaf sessile, subamplexicaul, ovate to lanceolate, 6.5-12.5 x 2.5-5 mm. Ochreolae 4-5 x 2-3 mm, ovate, acute. Flowers 2.0-2.5 (-3) mm across shortly pedicellate. Tepals 4-5, obovate, obtuse, light pink-blue, 2.0-2.5 x 1.0-1.5 mm. Stamens 5-6, filaments short, fused at the base. Ovary biconvex or trigonous, with 2-3 unequal styles, styles united at base; stigma rounded or capitate. Nuts biconvex or trigonous, shining, 1.75-2.0 x 1.75-2.0 mm, black, enclosed within slightly accrescent ± papery perianth.
Fl. Per.: June-September.
Type: Hab. in Nepalia, Wallich. (K!).
One of the most common species of Persicaria in our region, grows along water canals, in moist shady places, among rocks and stones from 1200-3500 m; Distribution: Tropical Africa, Afghanistan, Himalaya, Pakistan, India, China extending to Japan.
A highly variable species particularly in the indumentum, size of the heads, involucral leaves and biconvex or trigonous nuts. Usually winged petiole and trigonous nuts are said to be present in P. alatum Buch.-Ham. ex Spreng. However,these characters seem to form a continuum and we failed to distinguish between P. alatum and P. nepalense. Clarke's 30902 (K) from Sonamarg, Kashmir has trigonous nut but petiole is slightly winged.