LICHENS possess two distinct characters ; several are nutritious, some bitter, and some. yield to ammoniacal solutions a variety of bril liant colours, and are much used as dye-stuffs.
Lichen bread is used in Finland in times of scarcity. They are perennials, spreading in the form of a crust over rocks, trees, or the surface of the earth. On the Kumla Hills of the Neil gherry Hills, all the rocks are covered by lichens. Of lichens, the Stricta orygonosse and several other species give a beautiful pink dye ; Parmelia periolata and P. Nepalense yield a yellow dye ; P. borreri, a deep brown dye.
Ramalina farinacea is used for food. R. vul pina yields a fine deep yellow dye; and the follow ing are plentiful on the Kundas, viz. Cetraria glauca,, Cetraria, sp., Parmelia periolata, Lecanora tartarea, Gyrophora deusta, Cladonia rangiferina.
Rocella fusiformis, a dye lichen of Ceylon, was sent to the 1851 Exhibition, and there valued at £380 the ton. Parmelia periolata, a dye lichen of Ceylon and the Neilgherry Hills, was sent to the Exhibition of 1851, and was valued then at £195 to £225 per ton. Other dye plants are Lecanora atra, L. hmmatomma, L. parella, Ach., and L. tartarea, Ach.
Alectoria jubata, the Keh-Kieo of Ramrce, is a gelatinous lichen, and is eaten with rice by the natives.
Several lichens grow on the top of the Donkia pass, as Cladonia verinicularis, the yellow Lecidea geographica, and the orange L. miniata, also some barren mosses. At 18,300 feet, Dr. Hooker found on one stone only, a fine Scotch lichen, a species of Gyrophora, the 'tripe de roche' of arctic voyagers, and the food of the Canadian hunters ; it is also abundant on the SCotch,alps. Parmelia Kamtschadrdis, Esch., occurs in the Panjab bazars. It is used as a dye and as a stimulant to digestion in disorders of the stomach and womb, and in cases of calculus. Its vernacular name is chalcha
lira, also ashneh. The chief lichens employed in the manufacture of orchil and cudbear are the Angola weed, Ramalina furfuracea, and Mauritius weed, Rocella fusiformis, which, however, comes also from Madagascar, Lima, and Valparaiso, and I then bears the distinctive commercial name of the port of shipment.
Boccila tinctoria, from Tenasserim and other parts of India, had been introduced by the E.I. Company. R. tinctoria. and R. fusifonnia furnish the orchil or orchilla weed of commerce, which is sometimes sold as a moist pulp, but usually in the form of dry cakes, known under the name of litmus ; it produces a finepurple colour. The English imports aro derived chiefly from the Canary, Azores, and Cape de Verd Islands. Rock orchilla was shown at the Exhibition of 1851 ; from the Berlingen Isles, from Angola, Madeira, and the Cape de Verds. Orchilla weed is very plentiful about the shores of the islands of New Zealand, sonic was sent from thence to that Exhibition ; but from a want of knowledge as to the time at which it should be gathered, and the mode of preparing it for the market, it had not yet become a saleable commodity. The rich varieties of lichens on the rocks and plains of Australia have not been tested as they ought to be. Iceland moss (Cetraria Islandica, Hof.) is chemically allied to starch; it swells in water, and when boiled gelatinizes on cooling. It is used by invalids.
The Cladonia rangiferina, Hoff, is the reindeer moss, that animal using it as its winter food.— Hooker, Him. Jour. ii. p. 130; O'Sh. p. 671 ; Dr. J. L. Stewart, p. 269.