Physcia millegrana, commonly known as the mealy rosette lichen,[1] is a species of corticolous (bark-dwelling), foliose lichen in the family Physciaceae.

It is common in the eastern United States.

[1] It was formally described as a new species in 1940 by the lichenologist Gunnar Degelius.

[2] This gray lichen with a pale underside is characterized by its coarse soredia (granular vegetative propagules) that are densely distributed the margins of lobes, giving them a somewhat ruffled appearance.

[3] Secondary metabolites (lichen products) found in Physcia millegrana include atraric acid, methyl 3-hydroxy orsellinate, and divaricatic acid.