Gyalectidium australe

Gyalectidium australe is a species of lichen-forming fungus in the family Gomphillaceae. It is a leaf-dwelling lichen known from Queensland, Australia, and Yunnan, China, forming tiny silvery-grey patches on living leaves. The species is distinguished by its very small, regularly dispersed thallus patches that produce small, horizontal, tongue-shaped reproductive structures at their margins, and it is one of the few members of its genus that develops disk-shaped fruiting bodies....read more on Wikipedia.