ICELAND MOSS, Cetra•ia islandica, a lichen found in all the northern parts of the world, and valuable on account of its nutritious and medicinal properties. It is col lected as an article of commerce in Norway and Iceland. -In very northern regions it grows even near the level of the sea; in more southern countries, it is found on moun tains. It is not uncommon in the mountainous parts of Britain, although not turned to any economic account. In Carniola it is used for fattening cattle and pigs. It grows in extreme abundance in Iceland on tracts otherwise desert; and numerous parties migrate from great distances with horses, tents, and provisions, in the summer months, for the sole purpose of gathering it, as an article of and for food. In many places, this lichen thickly covers the whole surface of the ground, growing about 11 to 4 in. high, and consisting of an almost erect tha//ns (q.v.). It is of a
leathery and somewhat cartilaginous snbstance. When Iceland moss is used as an article of food, its bitterness is first partially removed by steeping in water, after which, in Iceland and other northern countries, it is sometimes pounded and made into bread; or it is prepared by boilime the first water being rejected. It is often boiled with milk, making a kind of jelly, either with milk or water. It is an agreeable article of food, and very suitable for invalids. It contains about SO per cent of a kind of starch called lichen starch, or lichcnin, and owes its bitterness to an acid principle, cetrarie acid. — Au allied species, cetraria niccdis, growing fir northern countries, possesses similar properties. It is very abundant in some parts of Iceland, is much used for food, and is called Mary's grass by the Icelanders.