CLADO'NIA, a genus of Planta belonging to tho natural oral Licheues. It has a thalins somewhat shrubby, branched, rarely sitnple, may, with scales, which are often evanescent ; branches cartilaginous.
rigid, fiatuloee, all attenuated and subulate, divided, fertile, generally i)erforated in the axils. Shields sessile, orbicular, convex, capituli rorm, not bordered, fixed by the circumference, free beneath in the :..entre, the sides reflexed, uniform within. The genus Cladonia thus :defined, with Seyphophores and Pyrnothelia, are included by Achariue end Delisle in the genus Crnomyce. Sir W. Hooker observes of this genus, that " the determination of the species is attended with the greateat difficulty, on account of their variable character; and in the present state of my knowledge I dare not venture upon introducing others than those published in English Botany. Much attention has been given to this genus by Delisle in the ' Botanicum Gallimn,' who, with Acharins, unites this and the two following genera into one, Cenomyee, and enumerates fifty-threo species, benides many marked varieties, as natives of France ; all of which are most probably natives also of Britain. Ito would render an acceptable service to British Botany who should undertake a monograph of the British Cladonietr." Hooker enumerates only five British species.
C. rangiferina, Rein-Deer Moss, has erect, elongated, roughish, cylindrical, greenish-white, very much branched podetia, the axils perforated, the branches scattered, often intricate divaricated, the alter ate ones drooping, apothecia subglobose, brown, on small erect branchlets. This is a frequent plant in Great Britain, on moors, heaths, and mountains. Its botanical characters are very variable, more especially the colour and the length of the ramifications. This may be accounted for by the wide range of latitude in which it is found, extending from the arctic regions, where it is most abundant, to the tropics. This plant is the principal support of the rein-deer in its native countries, and hence its common name. In Lapland there is no plant so abundant RS this, especially in the pine forests, where it covers the surface of the soil for many miles together like snow. On the destruction of the forests by fire this plant continues to grow, and then matches its greatest luxuriance. In such districts the rein-deer are principally pastured iu the winter; and whatever may be the depth of snow, these animals are enabled to obtain their food by grubbing with their noses through the snow. It would be quite impossible that the rein-deer should exist in these climates during the winter were it not for this apparently insignificant plant. The Laplanders aro also in the habit of collecting this lichen with rakes in the rainy season, when it is flexible, and readily separates from the ground where it has grown ; they then lay it up in heaps to serve as fodder for their cows. Dr. Clarke and his companions, during his travels in Laplandy were tempted to eat some of this lichen. " To our surprise," he says.
" we found that we might eat of it with ns much ease as of the heart of n fine lettuce. It tasted like wheat bran. But after swallowing it there remained in the throat and upon the palate a gentle heat or sense of burning, as if a small quantity of pepper had been mixed with the lichen. We had no doubt that if we could have procured oil and vinegar it would have made a grateful salad. Cooling and juicy as it was to the palate, it nevertheless warmed the stomach when swallowed, and cannot fail of proving .a gratifying article of food to man or beast during the dry winter of the frigid zone. Yet neither Laplanders nor Swedes eat of this lichen." Tide might arise from the fact which Dr. Clarke relates shortly after, namely, "that when Gustavus III. succeeded to the throne an edict was published and sent all over Sweden, recommending the use of this lichen to the peasants in time of dearth, and they were advised to boil it in Such an edict would be likely to have the effect of preventing people from eating it, as it would from that time forth be only looked upon as a last resource. Dillenius however states that when in water it yields no jelly, its substance is very little diminished, and becomes drier than before; and the dcooction evaporated yields only a small quantity of an acerb and austere extract The alimentary secretion of this plant appears to be similar to that of other lichens. It is called Lichenin, or Lichen Starch, and contains the same elements as starch. No nitrogen has been detected. It is however probable that nitrogen will be found to exist in this lichen, as during the winter it sup plies the rein-deer with food which must require a nitrogenous com pound in order to maintain its muscular power, unless we have recourse to the supposition that starch or lichenin, by union with free nitr Ten in the system, can be converted into fibrin° or other proteinamona compounds.
C. rcrmicularis, Vermicelli Lichen, has its podetia spreading horizon tally, pure white, nubulate, simple or slightly branched, branches tapering at each end. It has been found not infrequent on the loftiest mountains of the north of England and Scotland. The shape of its branches give it the appearance of a bundle of small worms or of vermicelli. It is a native of South America, where it is used as a stomachic under the name of Contrayrrba !dance.
C. sanguinea has a leafy very thick imbricated that's, scarlet, and frosted with white beneath ; above, green and somewhat gelatinous ; the lobes ercaulated, ascending ; podetia nearly solid, cavernous, split into fingered lobes, either wholly or at their apex only ; tho shields marginal, confluent, scarlet. This pretty form is a native of the Brazils, where it is rubbed down with sugar and water, and Is found to be an excellent remedy for aphtice in children. The remaining described British species are C uncle/is, a pungens, C. furcate.
(Lindley, Flora Medica ; Burnett, Outlines of Botany; Hooker, BMW Flora, vol. ii.)