About Physcia millegrana Degel.
Physcia millegrana, commonly called the mealy rosette lichen, is a species of corticolous (bark-dwelling), foliose lichen that belongs to the family Physciaceae. It is common in the eastern United States. Lichenologist Gunnar Degelius formally described it as a new species in 1940. This gray lichen has a pale underside, and is defined by its coarse soredia, which are granular vegetative propagules. These soredia are densely distributed along the margins of the lichen's lobes, giving the margins a somewhat ruffled look. Secondary lichen metabolites that have been found in Physcia millegrana include atraric acid, methyl 3-hydroxy orsellinate, and divaricatic acid.
