Bacidiaceae Tephromela grumosa Growth type crustose Chemical results: K+ yellow, C-, KC-, P-, UV- Found on well-lit siliceous rocks with most records from upland areas. Surface of thallus is +/- completely covered with dark bluish-grey, granular soredia. Dark blue-black prothallus usually present. Rarely fertile, apothecia with sorediate margins. Pycnidia absent. Similar: Lecanora pannonica. Soredia formed in excavate soralia. K+ yellow, P+ weak yellow

Tephromela grumosa
On ironstone. Studland, Dorset. April 2013