Porinaceae Porina linearis Chemical results negative. Thallus scratches yellow Can form large patches under shaded rocks on hard, sheltered limestone. Thin or endolithic thallus can be pinkish, grey or brownish. Scratches orange. Black perithecia 0.24-0.4mm, half immersed or superficial, the involucrellum purple-brown. Black pycnidia, +/- immersed. Spores 3-septate, sometimes curved, 16.5-22 x 4-6(-7) µm. Micro photographs below. Similar: Porina byssophila, thick grey-green thallus, spores 3-7 septate. Arthopyrenia saxicola. The 1-septate spores can become brown and thinly 3-septate when over-mature

Microscope photographs




Porina linearis
Dancing Ledge, Sturminster Marshall and Canford Magna, Dorset. February 2013, March 2014, January 2016