Lichen tapestry on oak tree bark

Description:

The lichen at center (and scattered on the bark of this tree) with the orange fruiting bodies (apothecia) is Xanthomendoza montana (syn. Xanthoria montana). It is sensitive to sulfur dioxide and can be used to monitor air pollutions. Thallus growth rate is in the 5 to 7 mm per year range.Most, but not all, species of Xanthomendoza grow on tree bark.There are at least another four to five species here including a gray foliose species (left-center).Oct. 19, 2012, Salt Lake County foothills, approx. 4850 ft. elev., growing on Quercus gambelii, Gambel's oak.