Lecanoraceae Lecanora praepostera Growth type crustose Chemical results: K+ yellow > red, C-, P+ orange-red, UV- A coastal species found on +/- sheltered vertical, siliceous sea cliffs on south-west and western coasts Areolate creamy-grey or pale creamy-greenish thallus with a zoned, bluish-tinged prothallus. Apothecia are in small groups or dispersed, discs pale brown or greyish-brown, becoming dark blackish-brown when old. Spores simple, 11-15 x 6-8 µm. Could be confused with Tephromela atra or Lecanora gangaleoides

Lecanora praepostera
On chert, Portland, Dorset. February 2016