_Radix Graminis_; _Couch Grass_, _Quitch Grass_, _Dog’s Grass_; F.
_Chiendent commun ou Petit Chiendent_; G. _Queckenwurzel_, _Graswurzel_.
=Botanical Origin=—_Agropyrum repens_ P. Beauv. (_Triticum repens_ L.),
a widely diffused weed, growing in fields and waste places in all parts
of Europe, in Northern Asia down to the region south of the Caspian,
also in North America; and in South America to Patagonia and Tierra del
Fuego.
=History=—The ancients were familiar with a grass termed [Greek
Agrôstis] and _Gramen_, having a creeping rootstock like that under
notice. It is impossible to determine to what species the plant is
referable, though it is probable that the grass _Cynodon Dactylon_
Pers., as well as _Agropyrum repens_, was included under these names.
Dioscorides asserts that its root taken in the form of decoction, is
a useful remedy in suppression of urine and vesical calculus. The
same statements are made by Pliny; and again occur in the writings
of Oribasius[2717] and Marcellus Empiricus[2718] in the 4th, and of
Aëtius[2719] in the 6th century, and are repeated in the mediæval
herbals,[2720] where also figures of the plant may be found, as
for instance in Dodonæus. The drug is also met with in the German
pharmaceutical tariffs of the 16th century. Turner[2721] and Gerarde
both ascribe to a decoction of grass root diuretic and lithontriptic
virtues. The drug is still a domestic remedy in great repute in France,
being taken as a demulcent and sudorific in the form of _tisane_.
[2717] _De virtute simplicium_, cap. i. (Agrostis).
[2718] _De medicamentis_, cap. xxvi.
[2719] Tetrabibli primæ, sermo i.
[2720] As in the _Herbarius Pataviæ_ printed in 1485, in which it is
said of _Gramen_—“aqua decoctionis ejus ... valet contra dissuriam ...
et frangit lapidem et curat vulnera vesicæ et provocat urinam....”
[2721] _Herball_, part 2, 1568. 13.
=Description=—Couch-grass has a long, stiff, pale yellow, smooth
rhizome, ⅒ of an inch in diameter, creeping close under the surface of
the ground, occasionally branching, marked at intervals of about an
inch by nodes, which bear slender branching roots and the remains of
sheathing rudimentary leaves.
As found in the shops, the rhizome is always free from rootlets, cut
into short lengths of ⅛ to ¼ of an inch, and dried. It is thus in the
form of little, shining, straw-coloured, many-edged, tubular pieces,
which are without odour, but have a slightly sweet taste.
=Microscopic Structure=—A transverse section of this rhizome shows
two different portions of tissue, separated by the so-called
nucleus-sheath. The latter consists of an unbroken ring of prismatic
cells, analogous to those occurring in sarsaparilla. In _Rhizoma
Graminis_, the outer part of the tissue exhibits a diffuse circle of
about 20 liber bundles, and the interior part about the same number
of fibro-vascular bundles more 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. Müller[2722] about 3 per cent. of sugar, and
7 to 8 per cent. of _Triticin_, C₁₂H₂₂O₁₁, a tasteless, amorphous,
gummy substance, 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 present as in taraxacum (p. 394), for such is the
inference we draw from the opposite results obtained by Stenhouse and
by Völcker. Starch, pectin and resin are wanting. The rhizome leaves 4½
per cent. of ash.
=Uses=—A decoction of the rhizome has of late been recommended in
mucous discharge from the bladder.
=Substitutes=—_Agropyrum acutum_ R. et S., _A. pungens_ R. et S., and
_A. junceum_ 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 _Gros Chiendent_ or
_Chiendent pied-de-poule_ 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 _Cynodin_ of
Semmola[2723]), or a substance similar to it.
[2722] _Archiv der Pharm._ 203. (1873) 17.
[2723] Della Cinodina, nuovo prodotto organico, trovato nella gramigna
officinale, _Cynodon Dactylon_.—_Opere minori di Giovanni Semmola_,
Napoli, 1841.—Abstracted in the _Jahresbericht_ of Berzelius, Tübingen,
1845. 535.
_II.—CRYPTOGAMOUS_ OR _FLOWERLESS PLANTS._
=_Vascular Cryptogams._=