The lobes of the thallus are circular, elliptical, or irregularly angular, with a nearly flat top and smooth, dark olive-green upper surface.

The thallus attaches to the rock via an umbilicus and lacks both isidia and soredia, reproductive propagules found in some lichens.

[1] Reproductive features include apothecia, which are spore-producing structures, occurring one or two per squamule and immersed within the thallus.

These apothecia have a yellowish epihymenium and a hymenium that produce a wine red colour reacting to iodine staining.

[1] Peltula pseudoboletiformis typically grows on calcareous rocks that are exposed to the sun, particularly within grooves where rainwater and soil may accumulate.