Roccellaceae Dirina massiliensis f. sorediata Chemistry: Cortex K-, C+ rose-red. Medulla UV+ usually bluish-white Can be common on vertical calcareous rocks and walls, often found on N and E church walls, sometimes with Llimonaea sorediata Thick, whitish-grey, areolate thallus with brown prothallus. Surface +/- covered with granular soredia which can completely cover thallus. Fresh thallii scratching orange. Never fertile. Can be host to Lecanographa grumulosa, Spiloma auratum and Milospium graphideorum. Dirina massiliensis f. massiliensis is the fertile form. Similar: Dirina fallax was only recently separated from Dirina massiliensis and is confined to siliceous and acid rocks

Dirina massiliensis f sorediata
Holy Rood church, Wool, Dorset. September 2012. St Mary's, Chettle December 2018