How are vestibular disorders diagnosed? The inner earâs vestibular organs and the associated nerves and brain centers form a complex system that serves many functions and can be affected by a number of outside systems. A thorough evaluation of the inner ear may therefore require several different kinds of tests.
Birch and tea-leaved willow are the main species of tree found in Icelandic woodlands and shrublands. Birch is the only species of tree to form continuous natural woodlands in Iceland, although the occasional rowan or aspen can be found growing in among the birch trees. Mosses and lichens often abound in forests, both as undergrowth and epiphytes growing on trees.
Although it is not a vascular plant, the structure of Iceland moss can be mistaken for stems and leaves, which makes it look like a moss; the likeness in appearance may have been the reason for its name. Cetraria islandica is a fruticose, or shrub-like and bushy, lichen growing loosely on the soil to a height of 3-4 inches.