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

[2] It can be identified by its thin, leaf-like thallus, few (or sometimes no) tiny hair-like structures (cilia) on the edges, short lobes with powdery edges, and a black underside with few root-like structures (rhizines), along with a wide brown area without these structures.

[3] The species was first scientifically described by the Swedish lichenologist Gunnar Degelius in 1941.

Mason Hale transferred it to the then newly circumscribed genus Parmotrema in 1974.

[5] Parmotrema robustum has a widespread distribution, with reports from Europe, eastern Australia, New Zealand, India, Thailand, Papua New Guinea, Macaronesia, and the Neotropics, including Bolivia, Brazil, Colombia, Costa Rica, Ecuador, and Venezuela.