DESCRIPTION: Foliose.  The thallus of this frequently encountred lichen is made up of spreading lobes that are up to 7mm in diameter.  The upper surface is grey to grey-green, smooth and scattered with spots of powdery soredia. The lower surface is light brown becoming darker towards the centre. Chemical results:- Cortex K+ yellow, medulla and soredia C+ carmine-red, KC+ red, UV-. DISTRIBUTION: Well distributed throughout Britain and Ireland but becoming rarer in the north. HABITAT: Found on well-lit trees and rocky surfaces.