Order: Teloschistales       Family: Teloschistaceae Species: Xanthoria parietina Growth type foliose. Large yellow-orange thallus with wrinkled, overlapping lobes, greyish-yellow in shade. Lobules sometimes present in centre of thallus. Abundant apothecia, discs with smooth margins. Ascus 8-spored, the spores colourless and polaricular, 12-16 x 7-9 µm. Microscope photographs below. Sometimes host to Xanthoriicola physciae Common on nutrient-rich rocks, trees, walls and roofs throughout Ireland. Coastal in 'orange' and 'grey' zones, also occurs inland in both rural and urban habitats. Very resistant to air pollution and increasing rapidly due to nitrates and ammonia from car exhausts and agricultural chemicals. K+ crimson / purple. Similar: X. calcicola, X. polycarpa and X. ectaneoides / aureola

Microscope photographs









     


     
Xanthoria parietina.