What Lichens Are Edible?

What Lichens Are Edible? Cetraria islandica — Iceland moss (Alaska, Canada, Iceland, British Isles, Appalachian Mountains) Bryoria fremontii — wila. Parmelia perlata — kalpasi or black stone flower (throughout temperate Northern and Southern hemispheres) Are any lichens poisonous? Only a few lichens are truly poisonous, with species of Letharia and Vulpicida being the primary examples.