Rock tripe (Umbilicaria species)
Edible Parts: The entire plant is edible. Scrape it off the rock and wash it to remove grit. The plant may be dry and crunchy; soak it in water until it becomes soft. Rock Tripes may contain large quantities of bitter substances; soaking or boiling the plant in several changes of water will remove the bitterness. The plant has a bland taste, much like pasta or dumplings.
Note: Some lichens do contain toxic substances and even Rock Tripe can cause stomach cramps. The bitter substances may cause stomach aches if too much is consumed. Leach Rock Tripe over night and boil it thoroughly to remove the bitter substances.