Coastal lichen with lirellae

Coastal lichen with lirellae

Observation - Coastal lichen with lirellae - UK and Ireland. Description: Grey, indistinct, crustose thallus growing on slatey, siliceous rocks near high tide mark. Lichen has black lirellae. Chemical tests: C-, K-. Possibly Opegrapha cesareensis. Growing on same rocks: Ochrolechia parella (I think) and a lichen with distinct

Grey, indistinct, crustose thallus growing on slatey, siliceous rocks near high tide mark. Lichen has black lirellae. Chemical tests: C-, K-. Possibly Opegrapha cesareensis. Growing on same rocks: Ochrolechia parella (I think) and a lichen with distinct light grey thallus and lecideine apothecia.