 Parmeliaceae thalli are most often foliose, fruticose or subfruticose, but can be umblicate, peltate, caespitose, crustose, or subcrustose.One genus, "Nesolechia", is even a lichenicolous fungus.They can be a variety of colours, from whitish to grey, green to yellow, or brown to blackish (or any combination therein).