Parmeliaceae Melanohalea exasperata Growth type foliose Chemical reactions negative. Found on the well-lit twigs and branches of acid-barked deciduous trees but rarely occurs on trunks. The olive-green, wrinkled and adpressed lobes are covered with numerous warts with pale craters. Usually fertile, the reddish-brown apothecia with thick, warted margins and simple spores, 9-12 x 5-6 µm. Isidia are absent. Microscope photograph below. Sometimes host to Abrothallus bertianus

Microscope photograph

Melanohalea exasperata
Holton Lee and Studland, Dorset. December 2012 and 2013