The humble Icelandic Moss or Fjallagrös (Cetraria islandica) is a peculiar life form that is actually neiter moss nor grass (as its English or Icelandic name would suggest). Fjallagrös are in fact the result of the existence of a fungus and a type of algea! It has long been used as an alternative medicine in Iceland. The taste is uniquely bitter and tonic-y and is very popular in artisan cocktails of late. Grind, soak or boil to use.