Editing Lichen (section)

=== Food ===
{{Main|Edible lichen}}
Lichens are eaten by many different cultures across the world. Although some lichens are only eaten in times of [[famine]], others are a [[staple food]] or even a [[delicacy]]. Two obstacles are often encountered when eating lichens: lichen [[polysaccharide]]s are generally indigestible to humans, and lichens usually contain mildly toxic [[secondary compound]]s that should be removed before eating. Very few lichens are poisonous, but those high in [[vulpinic acid]] or [[usnic acid]] are toxic.<ref name="Emmerich1993"/> Most poisonous lichens are yellow.{{citation needed|date=February 2024}}

In the past, [[Iceland moss]] (''Cetraria islandica'') was an important source of food for humans in northern Europe, and was cooked as a bread, porridge, pudding, soup, or salad. It is also fed to cattle, pigs and ponies. ''[[Bryoria fremontii]]'' (edible horsehair lichen) was an important food in parts of North America, where it was usually [[Pit barbecue|pitcooked]]. Northern peoples in North America and Siberia traditionally eat the partially digested [[Cladonia rangiferina|reindeer lichen]] (''Cladina'' spp.) after they remove it from the [[rumen]] of caribou or reindeer that have been killed. [[Rock tripe]] (''Umbilicaria'' spp. and ''Lasalia'' spp.) is a lichen that has frequently been used as an emergency food in North America, and one species, ''[[Umbilicaria esculenta]]'', (''iwatake'' in Japanese) is used in a variety of traditional Korean and Japanese foods.<ref>{{Cite journal |last=Llano |first=George A. |date=1948 |title=Economic uses of lichens |url=http://link.springer.com/10.1007/BF02907917 |journal=Economic Botany |language=en |volume=2 |issue=1 |pages=15–45 |doi=10.1007/BF02907917 |issn=0013-0001}}</ref>