ICELAND MOSS, a lichen (Cetraria islandica) whose erect or ascending foliaceous habit gives it something of the appear ance of a moss, whence probably the name. It is often of a pale chestnut colour, but varies considerably, being sometimes almost entirely greyish white ; and grows to a height of from 3 to 4 in., the branches being channelled or rolled into tubes, which ter minate in flattened lobes with fringed edges. It grows abundantly in the mountainous regions of northern countries, and it is specially characteristic of the lava slopes and plains of the west and north of Iceland. It is found on the mountains of north Wales, north England, Scotland and south-west Ireland. As met with in commerce it is a light-grey harsh cartilaginous body, almost destitute of colour, and having a slightly bitter taste. It contains about 7o% of lichenin or lichen-starch, a body isomeric with common starch, but wanting any appearance of structure. It forms a nutritious and easily digested carbohydrate food; it is not, however, in great request.