Teloschistaceae Flavoplaca oasis (Caloplaca oasis) Growth type crustose Chemical results: Thallus K-, apothecia K+ red Occurs on basic substrates; limestone, mortar and concrete. Occasionally parasitic on Verrucaria species Thallus is thin and yellowish or +/- inconspicuous with abundant and crowded small (0.2-0.4mm) apothecia with very narrow margins. Discs are dark orange when dry but orange-yellowish when moist. Spores polarilocular, 9.5-13 x 4.5-6.5 µm, septum to 3-4 µm wide. Similar: C. holocarpa agg. On siliceous rocks, sometimes on wood

Caloplaca oasis
Studland churchyard, Dorset. October 2012. On cockle shell, Hampshire, November 2013