Lichen: Xanthoria aureola
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Name: Xanthoria aureola (Nyl.) Zahlbr
Overgrowing Verrucaria on the seashore.
Coastal specimen with Caloplaca and Physcia species.
Pronunciation: Xanthoria auriola
Conservation Evaluation: Least Concern
Xanthoria aureola showing apothecia.
Body Type: Crustose
VC Map Xanthoria aureola
Description: Similar superficially to Xanthoria parietina in having a yellow thallus with distinct lobes and thalline apothecia. However it is distinguished by having wrinkeled strap-like lobes crossing haphazardly across each other, the tip of the lobes being less than 3mm in width. Apothecia are frequently absent, but when present they are often in abundance. The disc is smooth and a darker colour (usually orange) than the thalline margin.
Chemical Tests: K+ deep purple or crimson, this helps distinguish it from the genus Candelaria which is K-.
Nature Notes: Frequently associated with Man because of its preference for nutrient rich (nitrogen based) substrate. Without Man’s impact on the environment it would be found solely on basic bark and calcareous rock, but the eutrophication of habitats attracts it to acid substrates. Usually found in coastal areas and on old buildings, walls and areas of animal droppings.
Vice county distribution map: See Map
Link: Map this species on the Lichen Survey
Other species recorded in Ireland:
Xanthoria calcicola Oxner
Xanthoria candelaria (L.) Th.Fr.
Xanthoria elegans (Link) Th.Fr.
Xanthoria parietina (L.) Th.Fr.
Xanthoria polycarpa (Hoffm.) Th.Fr. ex Rieber
Xanthoria ulophyllodes Räsänen
Text and images © Paul Whelan, 2009.