A foliose species with blue-grey to brownish, smooth to slightly pruinose, adpressed lobes with ascending margins. The lobe edges are usually covered in a bluish grey soredia and marginal soralia. The lower surface is almost white with light tan veins and simple rhizines.
Peltigera collina is mainly found in central and western Scotland where it grows on mossy tree trunks and rocks in sheltered woodland. BLS distribution map
Peltigera collina is distinguished from Nephroma parile on basis of the presence of veins and rhizines. It is distinguished from Sticta limbata on basis of the lack of cyphellae on the lower surface.
scottishlichens.co.uk 