Verrucariaceae Verrucaria muralis Growth type crustose Chemical results negative Common on bricks, mortar, soft limestone rocks and pebbles and on shells White to greenish-white thallus, immersed, smooth or cracked. Black perithecia are immersed or prominent, leaving shallow pits in substrate. Spores (17-)20-24(-27) x (7.5-)10-12.5(-14.5) µm. Microscope photographs below. Host to Opegrapha hochstetteri

Microscope photographs



Verrucaria muralis
Westbourne and Branksome Park, Dorset and on cockle shell, Hampshire. February and November 2013, February 2017