Cetraria islandica

Iceland Moss


Flora, fauna, earth, and sky...
The natural history of the northwoods


  • Cetraria, perhaps from the Latin caetra, a short Spanish shield
  • islandica, from the Latin, "of Iceland"
  • Common Name, from
  • Other common names include Iceland Lichen, Eryngo-leaved liverwort, Islaendisch Moos (Ger), Islandslav (Swe), Mousse d'Islande, Lichen d'Islande (Fr), Líquén de Islandia (Sp), Puklérka Islandská (Czech), Islanninjäkälä (Fin), Erba rissa, Lichene islandico (It)


  • Kingdom Fungi, the Fungi
    • Division Ascomycota, the Sac Fungi
      • Class Ascomycetes
        • Order Lecanorales
          • Family Parmeliaceae
            • Genus Cetraria
  • Taxonomic Serial Number: 190618
  • Also known as


  • A fruticose lichen with a small to medium brown thallus growing loosely on the soil. Usually tufted, many lobed, and irregularly branched. Colonies 2"-8" across.
  • Cushionlike growth, well suited to high winds in harsh environments. Imbibes water slowly and can endure prolonged wet periods.
  • Its plant half is of the genus Aspicilia which has optimum photosynthetic rates at the low temperatures of alpine environments.
  • Leaves
  • Stem
  • Roots
  • Fruit
  • Seed


  • Identifiable as
  • Distinguished from
  • Field Marks


  • Canada to Alaska; south to the Pacific Northwest, Colorado, the Great Lakes states, New England, and in alpine regions in the Appalachians to Tennessee.


  • As a lichen, very dependent on air humidity, and abundance is generally in direct relation to the relative humidity of the climate. Better adapted to cold climates than any other life form. Grows best in direct sun, and can grow on shallow, sterile soils. Because able to take up moisture from the air, the underlying soil is not as important a source of moisture as it is to vascular plants.
  • Most often found in sandy soil in exposed areas at high elevations. It commonly grows on moist or dry tundra among mosses or in the open. Also found on forested sites and rock crevices.
  • Lichens in general decline in productivity in older stands.
  • Lichens may be pioneer plants on some sites because they are dependent on air moisture rather than soil moisture and can tolerate shallow substratums. They can persist in environments too harsh for higher plants, provided humidity is sufficiently high for growth and temperature is sufficiently low to inhibit competitors. Northern boreal forests offer climatically optimal conditions for lichen growth because of slow plant succession and little competition from other plant forms.
  • Occurs in various habitats including heaths, dunes, coastal plains, lichen woodlands, bogs, meadows, and tundra. A widely distributed species, but generally does not reach ground cover dominance.
  • Mats of C. islandica may diminish seedling establishment
  • "Because it is able to draw moisture from the air, the underlying soil is not as important a source of moisture as it is to vascular plants."
  • "Lichens quite often serve as the flash point of ignition in woodlands and tundra and have an essential role in the spread of fire. Dry lichens resemble dead litter more than live tissue in their susceptibility to fire. Continuous lichen mats present an uninterrupted surface along which fire spreads. Lichen mats typically accumulate tree and shrub litter which adds to flammability."



  • Used in Scandinavia as a famine food and bread additive.
  • Has been used to treat coughs, tuberculosis, fevers, and scurvy.
  • It has traditionally held an important place in Chinese medicine.
  • Has also been used as a source of antibiotics.


  • Used widely in herbal medicine for various ailments and as a tonic.
  • One of the few lichens consumed by humans. A powder made from dried C.islandica can be boiled to yield a jelly used in soups in northern Europe. The powder is also used in breads and cereals.
  • Astringent qualities make it useful in tanning leather.
  • Yields a brown dye.
  • Lichens widely used as indicators of air pollution or air quality. Cetraria islandica exhibits an intermediate sensitivity to sulfur dioxide and to fluoride, and may be useful as an indicator of high concentrations of these chemicals. Lichens, including C. islandica, also absorb radioactive fallout.
  • Iceland moss came into its own at the height of the world-wide incidence of tuberculosis when it was believed that this lichen killed or, at any rate, inhibited the development of the tubercle bacillus. Today it is still taken as a remedy for a range of bronchial conditions including respiratory catarrh, bronchitis and asthma, as well as being used as an agent in the battle against the debilitating gastro-enteritis.
  • The plant makes a nourishing food but must be boiled for a long time to rid it of its bitterness. As a food it is a particularly helpful boost to people suffering from malnourishment and debility. A note of warning. In excessive doses or with prolonged use, Iceland moss can cause gastric irritation and liver problems.


  • Produces spores, but sexual reproduction is infrequent.
  • Reproduction mainly occurs by means of thallus fragmentation or the dispersal of isidia and soredia. Wind or animals may play an important role in the dispersal of these vegetative propagules.


  • By rhizome division,


  • Hardy to USDA Zone 3 (average minimum annual temperature -40ºF)
  • Cultural Requirements
    • Sun
    • Soil
    • Water
    • Spacing
    • Fertilization
  • Size 12"-18"W x 12"-18"H
  • Growth rate
  • Good for
  • Cultivars include
    • variety 'Alba', with
  • Cultivars and species available by mail order from specialty suppliers or at local nurseries



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Last updated on 19 April, 2004