Oe ——— 
CHARACEA. 763 
and cudbear. (See Roccella.) It is also reputed to possess diuretic pro- 
perties. 
Peltigera.—Peltigera (Peltidea) canina and P. rufescens are known in the 
herb shops of this country under the name of Ground Liverwort. This 
was at one time official in the London Pharmacopeeia, and regarded as a 
specific in hydrophobia. 
Roceella, Orchella Weeds.—R. tinctoria, R. fuciformis, and R. hypomecha, 
under the common name of Orchella Weed, are the species usually met with 
in this country. They are imported from various parts of the world, as the 
Canary and Cape de Verd Islands, the Azores, Angola, Madagascar, Mauri- 
tius, Madeira, South America, Cape of Good Hope, &c. In commerce they 
receive the name of the country from whence they have been derived. 
Orchella weed is extensively used in the manufacture of the purple and red 
eolours called orchil and cudbear. In Holland, the blue colour called litmus 
is also prepared from the same Lichens; but the best kind is said to be made 
from &. tinctoria. Other Lichens, as species of Lecanora, Gyrophora, Par- 
melia, Variolaria, &c., are also sometimes employed in Britain and elsewhere 
for the preparation of orchil, &c. (See these species.) Orchil and cudbear 
are used for staining and dyeing purple and red colours, and also occasionally 
as tests for acids and alkalies. Litmus is employed as a test for alkalies, 
acids, and some salts with a basic reaction. It is official for this purpose in 
the british Pharmacopeia. A decoction of Orchella weed possesses muci- 
laginous, emollient, and demulcent properties, and has been used in coughs, 
eatarrhs, &c. 
Sticta pulmonaria, Tree Lungwort, Oak-lungs.—This lichen possesses 
tonic and nutritious ‘properties, somewhat resembling in these respects 
Cetraria islandica. In Siberia it is said to be used instead of hops for impart- 
ing bitterness to beer. It is also employed in France, &c., for the production 
of a brown dye. 
Variolaria.— V, dealbata and V. orcina are used for the preparation of 
Orchil in France. 
Order 3. CHARACE®, the Chara Order.—Diaqnosis.— Water 
plants, with a distinct axis branching in a whorled manner (jig. 
Fig. 1124. 
Fig. 1124. A small portion of a 
species of Nitella, magnified. 
The branches are arranged 
in a whorled manner. The 
contents of each cell exhibit 
a kind of circulation. The 
direction of this circulation 
is indicated by the arrows. 
The circulating matter does 
not pass from cell to cell, but 
is confined to that in which 
it originates. 
1124), and either transparent or coated with calcium carbonate. 
Reproductive organs of two kinds arising at the base of the 
