Heterodermia hypoleuca
DIAGNOSTIC FEATURES: Gray, fibrous, hard cortex; white, fibrous, soft undersurface at tips; NIS; cortex and medulla K+ yellow; compare with Physcia spp., cortical undersurface and H. squamulosa which is usually densely squamulose.
ECOLOGY: Widespread but not abundant on trees in the eastern US; scattered in Ohio, more common in the southeastern counties; on bark and rock.