Parmotrema lichexanthonicum is a species of foliose lichen in the family Parmeliaceae.

Found in Brazil, it was formally described as a new species in 1997 by Sionara Eliasaro and Mónica Adler.

The type specimen was collected by the first author from the Serra do Cipó (Santana do Riacho, Minas Gerais); here the lichen was found growing on a rock.

The specific epithet lichexanthonicum refers to the presence of the secondary compound lichexanthone in the medulla of the lichen.

[2] A close relative to this species is Parmotrema ultralucens, which contains the same cortical and medullary metabolites.