Platismatia herrei is a species of corticolous (bark-dwelling), foliose lichen in the family Parmeliaceae.

The lichen is found in western North America, ranging from southern Alaska to central California.

Its thallus is whitish or pale, often splotched with black, with flat to curled inwards lobes that are narrow and linear.

Ancestral state reconstruction suggests that P. herrei, an asexual species, likely evolved from a sexually reproducing ancestor.

Further research with increased sampling and additional genetic loci is needed to fully resolve the relationship between P. herrei and P. stenophylla.