Whitish crustose lichen

Whitish crustose lichen

Observation - Whitish crustose lichen - UK and Ireland. Description: Whitish crustose thallus growing on ash tree. Lots of lecanorine apothecia with light brown discs but most covered with thick pruinose coating . No apothecia in wide outer band of the thallus. Thallus: K+ yellow. Apothecia: C+ yellow. Possibly Lecanora

Whitish crustose thallus growing on ash tree. Lots of lecanorine apothecia with light brown discs but most covered with thick pruinose coating . No apothecia in wide outer band of the thallus. Thallus: K+ yellow. Apothecia: C+ yellow. Possibly Lecanora carpinea.