Rock tripe is the common name for various lichens of the genus Umbilicaria that grow on rocks.[1] They can be found throughout northern parts of North America such as New England and the Rocky Mountains. They are edible when properly prepared (soaking for hours to remove bitterness and purgative properties).[2] They have been used as a famine food in extreme cases when other food sources were unavailable, as by early American northern explorers.[2]

Rock tripe
Blistered Rocktripe (3560427638).jpg
Umbilicaria hyperborea
Scientific classification e
Kingdom: Fungi
Division: Ascomycota
Class: Lecanoromycetes
Order: Umbilicariales
Family: Umbilicariaceae
Genus: Umbilicaria
Hoffm. (1789)
Type species
Umbilicaria hyperborea
(Ach.) Hoffm. (1796)

Umbilicaria esculenta is commonly used as a food in Asian cuisine and a restorative medicine in traditional Chinese medicine. It is called shi'er (石耳 "rock ear") in Chinese cuisine, iwatake (岩茸 "rock mushroom") in Japanese cuisine, and seogi (석이버섯) in Korean cuisine.




  1. ^ Smith HB, Dal Grande F, Muggia L, Keuler R, Divakar PK, Grewe F, Schmitt I, Lumbsch HT, Leavitt SD. (2020). "Metagenomic data reveal diverse fungal and algal communities associated with the lichen symbiosis". Symbiosis. 82 (1–2): 133–147. doi:10.1007/s13199-020-00699-4.{{cite journal}}: CS1 maint: uses authors parameter (link)
  2. ^ a b Angier, Bradford (1974). Field Guide to Edible Wild Plants. Harrisburg, PA: Stackpole Books. p. 184. ISBN 0-8117-0616-8. OCLC 799792.
  3. ^ a b McCune, B. (2018). "Two new species in the Umbilicaria torrefacta group from Alaska and the Pacific Northwest of North America". Graphis Scripta. 30 (6): 65–77.