Why this Arctic lichen is a hidden powerhouse of nutrition and traditional medicine

Gardening · Published 3 October 2026 Swipe more like this →

In short: Iceland moss is not a moss at all, but a resilient lichen that has sustained humans and animals for centuries. From the lava fields of the North to the Rocky Mountains, this bitter, starch-rich organism has served as everything from a survival food to a specialized ingredient in traditional medicine.

Cetraria islandica, commonly known as Iceland moss, is an Arctic-alpine lichen characterized by its upright, leaflike growth. Despite its name, it is a fruticose lichen that typically reaches heights of 7 to 10.2 centimetres. Its appearance varies from pale chestnut to grayish-white, featuring branches that fork into flattened, fringed lobes. It thrives in mountainous regions across the Northern Hemisphere, particularly on the lava slopes of Iceland and throughout North America, ranging from Alaska to the Appalachian Mountains.

The lichen is chemically complex, containing about 70% lichenin, a polymeric carbohydrate often called lichen-starch. It also yields various acids, including fumaric, lichenostearic, and cetraric acid, the latter of which provides its signature bitter taste. Beyond its nutritional profile, the lichen serves as a host to the fungus Lichenopeltella cetrariicola and acts as an essential food source for reindeer, caribou, musk-oxen, and moose. Its utility extends to industry, where it is used in soap and cold cream manufacturing due to its glycerol content.

Historically, Iceland moss was a vital human food source, often incorporated into breads, soups, and porridges. While its modern use is limited, it remains a traditional remedy for chest ailments and dry coughs, often prepared as a bitter tonic. Because it is naturally bitter, preparation typically involves soaking and boiling to improve palatability. Though once a staple in northern diets, it is now primarily used as a niche ingredient or in alternative medicine, where it is sometimes recommended in small doses to soothe oral and pharyngeal irritation.

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