Parmeliaceae Parmelia sulcata Chemical results: Medulla, soredia K+ orange-red, C-, P+ orange, UV- Very common on both trees and rocks Overlapping bluish-grey lobes covered with a network of white reticulation. Greyish soredia can spread and completely cover the centre of the thallus. Underside black with simple/squarrose rhizines. Apothecia are most frequent in the North and West. Isidia are absent. Similar: Parmelia saxatilis. Isidiate, soredia are absent. Lichenicolous fungi on Parmelia's include Marchandiomyces corallinus, Abrothallus parmeliarum and Homostegia piggotii

Parmelia sulcata
October 2012, fertile specimen January 2013