Caloplaca marina (Wedd.) Zahlbr.
Orange Sea Lichen
Very common all round Britain on coastal rocks. A component the yellow Xanthoria/Caloplaca zone above the black Hydropunctarai maura zone on rocky shores. The bright yellow -orange thallus is often fragmented and may have a lobed margin and dark orange apothecia
Smith et al. editors (2009) The Lichens of Great Britain and Ireland
Dobson (2018) Lichens: an Illustrated Guide to the British and Irish Species