Cresponea graemeannae

Cresponea graemeannae is a species of saxicolous (rock-dwelling) crustose lichen in the family Opegraphaceae, described in 2020 from Tasmania, Australia. It forms very thin, patchy films on sandstone or dolerite and bears small, black, disc-like fruiting bodies with a thick, radially split margin. The species is set apart from related taxa by its almost inapparent thallus, thin greyish bloom on young fruiting body discs, a margin that reacts green in potassium hydroxide solution, an oil-dotted tissue beneath the spore layer, and thick-walled ascospores with between five and nine cross-walls....read more on Wikipedia.