Porinaceae Porina byssophila Growth type crustose. BLS conservation evaluation: DD NR Sc Chemistry negative. Involucrellum K+ blue-grey to dark grey-brown On limestone and slightly basic siliceous rock and stones, usually on shaded surfaces sheltered from rain. Also on old trees with base-rich bark, Thallus well-developed, dull greyish-green, green-brown or grey-brown. Perithecia usually in groups, 1/10 to 1/2 immersed. Spores 3(-7) septate (but usually 3-septate), (17-)18.5-24(-29) x (3.5-)4-5.5(-6) µm. Micrographs below. Similar: Porina linearis has an endolithic thallus. Porina chlorotica, involucrellum K- or K+ grey-brown

Microscope photographs







Porina byssophila
On stone Lytchett Minster and Branksome Park, Dorset. December 2016, January 2017.On bark Broadstone, Dorset. January 2023