Rinodina sophodes (Ach.) A. Massal.
A pioneer species on twigs. Usually on smooth-barked trees, particularly Fraxinus. Pale greyish to olive brown thallus occurs in small patches. Apothecia usually densely clustered, margins thick, conspicuous, pale grey (greener when damp), discs dark brown to black.
Smith, C.W. et al. editors (2009) The Lichens of Great Britain and Irelandd
Dobson, F.S. (2018) Lichens: an Illustrated Guide to the British and Irish Species
Ahti et al. editors (2002) Nordic Lichen Flora, Volume 2: Phyciaceae