Halecania lobulata

Halecania lobulata is a species of crustose lichen in the family Leprocaulaceae. The lichen forms small rosettes up to 5 mm across that grow over other crustose lichens on calcareous rocks, with a greyish to yellowish-brown surface that breaks into tiny leaf-like lobes at the margins. It produces isousnic acid and related compounds that give a yellow reaction when tested with potassium hydroxide solution. The species is known from North Korea and South Korea, where it grows on exposed rock outcrops in mixed forests and near waterfalls....read more on Wikipedia.