A foliose species with a yellow-grey to greenish thallus that consists of flat lobes that are closely adpressed and rather palmately divided. The lobe tips have discrete soralia and the centre of the thallus becomes covered with concolorous powdery soredia.
Cortex: K+ faintly yellow. Medulla: C-, K-, UV+ glaucous white
In Scotland, Parmeliopsis ambigua occurs mainly in central and eastern regions where it grows on acid-barked broadleaved and coniferous trees and wood. BLS distribution map
scottishlichens.co.uk 