396 



SUBTERRANEAN ORGANS 



Mucilage, inosite, and levulose are also constituents of the rhizome, 

 but starch is not present. 



Substitutes. Most of the commercial drug is imported from the 

 Continent and frequently consists of the rhizome of Cynodon Dactylon, 

 Persoon. This contains abundance of starch which affords a ready 

 means of distinguishing it ; the section is white 

 and is blackened by solution of iodine. 



5. Couch grass has been employed as a 

 diuretic in certain affections of the bladder. 



MALE FERN RHIZOME 



(Rhizoma Filicis Maris, Filix Mas) 



Source, &C. The male fern, Dryopteris 

 Filix-mas, Schott (N.O. Filicinece), is abundant 

 in Great Britain, and one of the commonest of 

 our indigenous ferns. It produces a circular 

 tuft of fronds attaining a metre in height and 

 arising from a stout rhizome. The lamina is 

 divided pinnately, and bears on its under 

 surface, when in fruit, kidney-shaped or some- 

 times nearly peltate sori. The petiole bears 

 numerous brown, scarious scales, especially in 

 the lower part. 



The rhizome is collected in the autumn ; 

 the fronds are cut off, leaving the lower swollen 

 portion, about 3 cm. in length, attached to the 

 rhizome, the roots are removed, and the 

 drug is then dried. Sometimes the rhizome 

 is cut longitudinally to facilitate the drying. 



Much is imported from Germany, large quantities being collected 



in the Harz and Thuringian Mountains. 



Description. The drug occurs in pieces up to about 12 or 15 cm. 

 in length, but usually shorter, and 4 cm. in thickness ; only about 

 one-half of this is due to the rhizome itself, the rest being formed 

 by the bases of the petioles that have been left attached to it. These, 

 which constitute the major part of the drug, are usually from 2 to 

 3 cm. in length, from 5 to 15 mm. in thickness, and enlarged near the 

 middle. They are curved, bluntly angular or longitudinally furrowed, 

 and of a dark brown or nearly black colour externally. They are 

 more or less densely covered with dry, brown membranous scales. 

 Examined under the microscope the marginal cells of these scales will 

 be seen to be prolonged at intervals into simple hairlike processes 



FIG. 215. a, transverse 

 section of base of 

 petiole of Aspidium 

 Filix-mas. b, trans- 

 verse section of petiole 

 of A. Filix-fo?mina ; 

 c, the same just below 

 the lamina. Slightly 

 magnified. (Luerssen.) 



