Cladonia rangiferina, also known as Reindeer lichen (c.p. Sw. renlav), lat., is a light-colored, fruticose lichen belonging to the family Cladoniaceae. It grows in both hot and cold climates in well-drained, open environments. Found primarily in areas of alpine tundra, it is extremely cold-hardy.
Other common names include Reindeer moss and Caribou moss. As the common names suggest, Reindeer lichen is an important food for reindeer (caribou), and has economic importance as a result.
This lichen can be used in the making of aquavit, and is sometimes used as decoration in glass windows. The Inland Dena'ina used reindeer lichen for food by crushing the dry plant and then boiling it or soaking it in hot water until it becomes soft. They eat it plain or, preferably, mixed with berries, fish eggs, or lard. The Inland Dena'ina also boil Reindeer lichen and drink the juice as a medicine for diarrhea. Due to acids in the plants, lichens may cause an upset stomach, especially if not well cooked.
A similar-looking species also known by the common name Reindeer lichen is Cladonia portentosa.