''Cladonia borealis'', commonly known as the boreal cup lichen, is a species of
lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.genus '' Cladonia''.
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Description
Cladonia borealis is yellowish green to brown in color. It occurs in North and South America, Antarctica, Eurasia and many on islands. The ascoma, when present is apothecial.
barbatic acid
Barbatic acid is an organic compound that is made by some lichens. It is in the structural class known as depsides. It is particularly common in the genera ''Usnea'' (the beard lichens) and ''Cladonia''.
History
The compound was first isolated ...
usnic acid
Usnic acid is a naturally occurring dibenzofuran derivative found in several lichen species with the formula C18H16O7. It was first isolated by German scientist W. Knop in 1844 and first synthesized between 1933-1937 by Curd and Robertson. Usnic a ...