Lecanora muralis (Protoparmeliopsis muralis) is a waxy looking, pale yellowish green crustose lichen that usually grows in rosettes radiating from a center filled with disc-like yellowish-tan fruiting bodies (apothecia). It grows all over the world. It is extremely variable in its characteristics as a single taxon, and may represent a complex of species. The fruiting body parts have rims of tissue similar to that of the main nonfruiting body (thallus), which is called being lecanorine. It is paler and greener than L. mellea, and more yellow than . In California, it may be the most common member of the Lecanora genus found growing on rocks (saxicolous).