Constrictolumina cinchonae

Constrictolumina cinchonae is a species of corticolous (bark-dwelling) crustose lichen in the family Trypetheliaceae. This widespread tropical lichen forms thin, whitish crusts on tree bark and produces small, hemispherical fruiting bodies that are often surrounded by distinctive grey rings. It has a pantropical distribution, being found across warm, humid regions of the Americas, Africa, and Asia, making it one of the most widely distributed members of its genus. The species was originally discovered growing on cinchona bark, which is reflected in its scientific name....read more on Wikipedia.