Diorygma africanum

Diorygma africanum is a species of corticolous (bark-dwelling) crustose lichen in the family Graphidaceae. It was described as new to science in 2004 by the lichenologists Klaus Kalb, Bettina Staiger, and John A. Elix, based on collections made in Cameroon. The species epithet alludes to its continent of origin, to which it was originally thought to be endemic, though it was later identified in Colombia. This bark-dwelling lichen forms thin grey crusts with conspicuous raised ridges that contain unusually large spores—each reproductive structure (ascus) typically holds just a single ascospore that can reach up to 200 micrometres in length. The species is distinguished from similar lichens by its unique chemical composition, particularly the presence of protocetraric acid and the absence of norstictic and salazinic acids....read more on Wikipedia.