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Emery Rock Tripe

Scientific Name:

Umbilicaria Phaea




Desert and other dry climates


Native to western North America, including Nevada County, CA, Washoe County, NV, and the Sagehen Creek Basin near Truckee, CA


No listed status

This species is


to the Truckee Meadows.


Emery rock tripe is a type of common lichen. Lichens are complex organisms that arise from symbiotic relationships between fungi and a photosynthesizer, like algae. This umbilicate foliose lichen will attach itself to another surface, usually a rock, with a single anchoring stem (umbilicate) and is readily identified by its flattened leafy appearance (foliose). Emery rock tripe tends to grow, sometimes in groups or patches, in desert areas or in other arid and dry climates in western North America and South America. While typically brown, some varieties in northern California and the Pacific Northwest grow a bright red. The leaf-like cap of the lichen tends to be very smooth and is host to many small black spots.

Fast Facts:

  • “Rock tripe” is a common name for lichens that grow on rocks from the genus Umbilicaria.

  • Given that rock tripe can thrive in some of the harshest environments and “survive” volatile winters, they have long served as “emergency food” for indigenous Americans, soldiers, and expeditioners out west. The Inuit people of the Canadian arctic regions consider rock tripe a “food of last resort.” During the American Revolution, General George Washington’s troops at Valley Forge boiled and ate rock tripe during a deadly winter while waiting on more supplies.

  • Native Candians believe rock tripe possess certain medicinal properties.

  • As a native species in Canada, the emery rock tripe is commonly misidentified as the common toadskin lichen, a lichen which is native and endangered in the Northwest Territories and Saskatchewan provinces of Canada.

  • Other “rock mushrooms” are sold as culinary delicacies and even used in dyes.



Taylor Gardner (research & content)

Alex Shahbazi (edits & page design)

Last Updated:

June 16, 2021 at 9:45:23 PM

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