Xanthoparmelia rubromedulla
Xanthoparmelia rubromedulla is a species of saxicolous, foliose lichen in the family Parmeliaceae. Found in South Africa, it was formally described as a new species in 1986 by the American lichenologist Mason Hale. The type specimen was collected from Waaihoek Peak at an elevation of, where it was found growing on a sandy rock face above a stream. The lichen thallus, which is loosely attached to its rock, is light yellowish green and measures in diameter. It contains salazinic acid, usnic acid, and skyrin.