CLASS VI. ORDER I.] ACORUS. 491 



quently by cultivation expands its stamens into petals and becomes 

 double, and it also varies in colour from dark reddish purple to pink 

 and white. 



GENUS XVIII. ACO'RUS.— Linn. Sweet Sedge. 



Nat. Ord. Aroi'de^. Juss. 



Gen. Char. Flowers arranged upon a spadix. Spatha wanting. 

 Perianth of six persistent pieces or scales. Stamens opposite the 

 divisions of the perianth. Stigmas obtuse, sessile Fruit a dry 

 three celled, three valved, many seeded capsule. — " Named from a, 

 without ; and ^to^tov, or yio^n, the pupil of the eye, the diseases of 

 which it was supposed to remove." — Hooker. 

 1. A. Ca'lamus, Linn. (Fig. 558.) Common Sweet Sedge, or Flag. 

 End of the scape rising much above the spadix, long and leafy. 



English Botany, t. 356.— English Flora, vol. ii. p. 157.— Hooker, 

 British Flora, vol. i. p. 163. — Lindley, Synopsis, p. 146. 



Rhizoma thick, large, fleshy, or somewhat spongy, putting out nu- 

 merous long branched fibres, strongly aromatic, much more so than 

 the stems and leaves. Scape compressed, striated, from two to three 

 feet long, bearing the spadix of flowers about the middle or below that ; 

 about the spadix it is similar to the leaves. Leaves linear lanceolate, 

 about as long as the scape, sword-shaped, smooth, finely striated, of a 

 bright green colour. Spadix generally about three inches long, cylin- 

 drical, tapering at the point, thickly crowded with sessile deciduous 

 flowers. Perianth of six obtuse or acutely pointed pieces, concave, 

 keeled at the back, somewhat thickened at the base. Stamens with 

 thick equal filaments, as long as the perianth. Anther small, yellow, 

 of two lobes, bursting laterally. Stigmas sessile, of three lobes. Cap- 

 sule obtusely triangular, membranous, of three cells, or one by abortion. 

 Seeds mostly several, ovate oblong. 



Habitat. — Banks of rivers and watery places, in the Middle and 

 Southern Counties of England; abundant in Norfolk and Suffolk. 

 Rare in Scotland, Ayrshire, Loch Winnoch, Renfrewshire.— Mr. 

 Paterson. Castle Semple Loch.— Z>r. Logan. 

 Perennial ; flowering in May and June. 



The Sweet Smelling Flag has been long used as a medicine. The 

 root has a moderately strong aromatic smell, is bitter, and forms an 

 agreeable tonic, which has been exhibited beneficially in cases where 

 a warm stomachic is wanted, and also in chronic catarrh and some of 

 the forms of asthma. The odour of the plant depends upon an essen- 

 tial oil, which is more abundant in the fleshy rhizoma than any other 

 part of the plant, and is in combination with the bitter principle and 

 farinaceous matter ; by drying it loses in a greater part its bitterness, 



