Show lichens of importance several species of lichens are anre ot of economic importance yielding dyes and foodstuffs iceland moss Is edible yielding a nutritious jelly reindeer moss Is the principal food of the lapland reindeer in the winter Arc archil lill a violet lye dye Is obtained from roccella torla roccella Roc colla fuci formis and le cazorla tartarea tar tarea litmus al also so a dyestuff Is obtained from these lichens by exposure to the air in the presence of ammonia potassium carbonate etc |