A foliose species that has an orbicular thallus that is grey to glaucous white with brownish tips. The lobes are overlapping, to 5 mm wide and ridged with a faint, coarse, network of white pseudocyphellae along which soralia develop. These soralia may spread and cover the centre of the thallus.
Cortex: K+ yellow turning red. Medulla and soralia: C-, K+ orange-red, UV-
Parmelia sulcata is very common throughout Scotland, and can be found on trees and rocks, especially in lowland areas. BLS distribution map
Parmelia sulcata is distinguished from Parmelia saxatilis by the presence of soralia rather than isidia.
scottishlichens.co.uk 