SWEET FLAG 395 



they require further investigation. The drug contains an abundance 

 of starch and a little tannin. 



Uses. The drug has stimulant and tonic properties ; it has been 

 used for ague and for atonic dyspepsia. 



COUCH GRASS RHIZOME 



(Rhizoma Tritici, Radiz Graminis) 



Source, &C. The couch grass, Agropyron repens, Beauvais (Tri- 

 ticum repens, Linne, N.O. Graminece), is abundant in this country, 

 being often a troublesome weed. It produces a slender rhizome, 

 running for a considerable distance just below the surface of the 

 ground, giving off lateral branches, and at the nodes, which are 2 

 to 3 cm. apart, small fibrous, roots. The rhizome, which appears 

 to have been used by the Greeks and Romans for certain affections 

 of the bladder, is collected, cut into pieces about 1 cm. long, and dried. 



FIG. 214. Couch Grass rhizome and transverse section ;' the 

 latter magnified 3 diam. (Maisch.) > g^ 



Description. Couch grass is generally met with in commerce 

 cut into short pieces. The rhizome is very slender, averaging about 

 2 mm. in diameter, and of a dark straw-yellow colour. The sur- 

 face is quite glabrous, hard and shining and usually bears five or 

 six rather prominent longitudinal ridges. Some of the pieces bear 

 the nodes, at which there may be found the persistent fibrous 

 remains of a sheathing leaf -basis, and either a few threadlike paler 

 roots or the scars left by them. The transverse section exhibits, 

 under a lens, a narrow pale inner ring (the stele), hollow in the centre, 

 surrounded by a darker translucent cortex. 



The drug has but little odour, and a sweetish, mucilaginous taste. 



The student should observe 



(a) The slender hollow rhizome, 



(b) The translucent (not starchy) cortex. 



Constituents. Couch grass contains a carbohydrate, triticin (5 per 

 cent.), which is not very soluble in water, and yields by hydrolysis 

 levulose ; it appears to occur in the rhizomes of other Graminaceous 

 plants, and possibly is widely diffused in the vegetable kingdom. 



