Gallowayella weberi

Gallowayella weberi is a species of corticolous and saxicolous (bark- and rock-dwelling), foliose lichen in the family Teloschistaceae. Recorded from the eastern and central United States, it is a small lichen with a smooth yellow to orange upper surface and a contrasting white lower surface. It was previously placed in the genus Xanthomendoza and appears in older literature as Xanthomendoza weberi. Herbarium records indicate that it is widespread across the eastern and central United States, with its centre of distribution in the coastal plain of the Southeast, where it grows on bark, rock, and even concrete and other man-made surfaces....read more on Wikipedia.