Acorus calamus Linn., Sp. Pl. 324. 1753. Boiss., Fl. Or. 5: 44. 1884; Hook. f., 1. c.; Collett, Fl. Siml. 544. 1902; Kanjilal, For. Fl. Siw. & Jaun. 414. 1911; Bailey, l.c.; Kuzeneva, l.c. 480; Mitra, l.c.; H. Riedl in Rech. f., Fl. Iran. 1: 8. 1963.
Vern.: Bach, Kull.
Perennial herb up to 80 cm tall. Rootstock stout, 1-1.5 cm broad, creeping, with long fibrous roots from the lower surface. Stem erect, glabrous, grooved at one side, and ribbed at the opposite. Leaves ensiform or linear, 55-100 x 8-1.5 cm. Spathe leaf-like, up to 46 cm long, not enclosing the spadix. Spadix 5-6.5 cm long, cylindrical, obtuse, 1-1.4 cm broad. Tepals c. 2 mm long, oblong-obovate, slightly curved, margin membranous, surface with embedded raphides. Filaments 2 mm long, flat, anthers less than 1 mm long, ± orbicular. Ovary 3 mm long, obconical; seeds obconical, 2 mm long,
Fl. Per.: June July.
Type: ‘Habitat var. a. in Europae and var. b. in Indiae fossis paludosis’.
Distribution: N. and C. America, Europe, Asia.
‘Sweet flag’ is found in marshy places and along river banks from (600-) 1000-2000 m. The rootstock is medicinal and yields an oil used in the manufacture of soap, cosmetics and in the liquor industry; it is also medicinal, being used in stomach complaints, snake bite, as an insect repellant, and for remittent fevers.