Genus Cetraria is a type of lichen that is commonly known by several synonyms. Some of the commonly used synonyms for this genus include Iceland moss, sea moss, and Rock tripe. These synonyms generally come about as a result of the varied geographical locations where the lichen is found as well as its physical appearance. Iceland moss, for example, is found in Iceland and has a moss-like physical appearance. Similarly, sea moss is found near coastal regions, hence the name being derived from its proximity to the sea. Regardless of the name it is called, Genus Cetraria is widely used for medicinal purposes and is an important food source in some regions.