Family: Porinaceae Species: Porina byssophila Growth type crustose Photos: Kilcolman, Co. Limerick, Ireland. Thick dull greyish-green, green-brown or grey-brown thallus, the perithecia usually in groups, +/- immersed. Spores 3(-7) septate (but usually 3-septate), (17-)18.5-24(-29) x (3.5-)4-5.5(-6) µm. Micrographs below. Chemistry negative. Involucrellum purple-violet to purple-brown, K+ blue-grey to dark grey-brown On limestone and slightly basic siliceous rock and stones, usually on shaded surfaces sheltered from rain. Also found to be widespread on older trees with a base-rich bark. Similar: Porina aenea and Porina chlorotica usually have thinner, browner thallii and a different chemistry

Micrograph



Porina byssophila. August 2024