Genus Cladonia, commonly referred to as reindeer lichens, is a group of lichens found predominantly in arctic and alpine regions. Though the term Genus Cladonia pertains to a specific type of lichen, there are several synonyms that can be used to describe this plant. Some commonly used synonyms for Genus Cladonia are Cladina, Cladocollema, Cladinia, and Pycnothelia. Each of these synonyms pertains to lichen species that belong to the same family as the Genus Cladonia. While these synonyms may be used interchangeably, it's important to note that the biological characteristics of each species differ slightly, making them unique in their own way.