Xanthoparmelia denudata is a species of saxicolous (rock-dwelling), foliose lichen in the family Parmeliaceae. Found in Southern Africa, it was formally described as a new species in 1986 by the American lichenologist Mason Hale. The type specimen was collected in Cape Province, at an elevation of about ; there, it was found in a pasture growing on large exposed sandstone ledges. The dark yellowish-green thallus of the lichen reaches in diameter, although neighbouring thalli can coalesce to form larger units up to . The comprising the thallus are more or less linear in form, and measure 0.6âÂÂ1.3 mm wide. Three secondary metabolites (lichen products) have been found in Xanthoparmelia denudata: salazinic acid, usnic acid, and skyrin.