730 GEAMINEiE. 



densely packed. The pith is reduced to a few rows of cells, the rhizome 

 being always hollow, except at the nodes. No solid contents are to be 

 met with in the tissue. 



Chemical Composition — The constituents of couch-grass include 

 no substance to which medicinal powers can be ascribed. The juice 

 of the rhizome afforded to H. Miiller^ about 3 per cent, of sugar, and 7 

 to 8 per cent, of Triticin, C^^H^^O^^ a tasteless, amorphous, gummy sub- 

 stance, easily transformed into sugar if its concentrated solution is kept 

 for a short time at 110° C. When treated with nitric acid, it yields 

 oxalic acid. The rhizome affords also another gummy matter containing 

 nitrogen, and quickly undergoing decomposition ; the drug moreover is 

 somewhat rich in acid malates. Mannite is probably occasionally pre- 

 sent as in taraxacum (p. 394), for such is the inference we draw from 

 the opposite results obtained by Stenhouse and by Volcker. Starch, 

 pectin and resin are wanting. The rhizome leaves 4| per cent, of ash. 



Uses — A decoction of the rhizome has of late been recommended in 

 mucous discharge from the bladder. 



Substitutes — Agropyrwm acutum R, et S., A. pungens R. et S., and 

 A. junceuTYi P. Beauv., by some botanists regarded as mere maritime 

 varieties of A. repens, have rootstocks perfectly similar to this latter. 



Cynodon Dactylon Pers., a grass very common in the South of 

 Europe and the warmer parts of Western Europe, also indigenous to 

 Northern Africa as far as Sennaar and Abyssinia, affords the Gi'os Chien- 

 dent or Chiendent pied-de-2)oule of the French. It is a rhizome differing 

 from that of couch-grass in being a little stouter. Under the microscope 

 it displays an entirely different structure, inasmuch as it contains a 

 large number of much stronger fibro-vascular bundles, and a cellular 

 tissue loaded with starch, and is therefore in appearance much more 

 woody. It thus approximates to the rhizome of Carex arenaria L., 

 which is as much used in Germany as that of Cynodon in Southern 

 Europe. The latter appears to contain Asparagin (the Gynodin of 

 Semmola'^), or a substance similar to it. 



^ Archivder Pharm. 2J03. (1873) n. mola, Napoli, 1841.— Abstracted in the 



2 DellaCirtocZijia, nuovoprodottoorganico, Jahresbericht of Berzelius, Tubingen, 1845. 



trovato nella gramigna officinale, Cynodon 535. 



Dactylon. — Opere minori di Giovanni Sem- 



