Fringed rosette lichen has apothecia that are common on upper surface, black discs on short stalks or without stalks. Its thallus is foliose and dichotomously branched. The upper surface is white to grey-green, often with tiny blocks spots. Branches are linear with long-ciliate tips, cilia grade from translucent to white to black. Rhizines on lower surface.
It can be distinguished from P ascendens, by its flat and narrow branch tips (vs ones that curl in toward each other, forming tube-like hoods). It can be distinguished from Hypogymnia physodes by its long-ciliate margins (vs none).