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

Known predominantly from western North America, it reproduces primarily through sexual means, which is uncommon in the genus.

The species is distinguished by its ridged surface and large, folded apothecia (fruiting bodies).

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

[3] Platismatia lacunosa is found in Asia, Europe, and western North America.