Flavoparmelia soredians

Flavoparmelia soredians is a widely distributed species of foliose lichen in the large family Parmeliaceae. In the late 1990s, an increase in the frequency of Flavoparmelia soredians was noted in the Netherlands, which, until then, occurred rarely in the country. This population increase followed a decrease in the levels of the pollutant sulphur dioxide. Punctelia borreri and Flavoparmelia caperata were two other foliose species that experienced a similar increase in regional frequency during this time....read more on Wikipedia.