Astrothelium laurerosphaerioides
Astrothelium laurerosphaerioides is a species of corticolous, crustose lichen in the family Trypetheliaceae. Found in Guyana, it was formally described as a new species in 2016 by Dutch lichenologist André Aptroot. The type specimen was collected by Harrie Sipman on Kusad Mountain at an altitude of ; there, it was found in a savanna growing on smooth tree bark. The lichen has a smooth and shiny, pale ochraceous-green thallus with a cortex, which covers areas of up to in diameter. An anthraquinone compound was the only lichen product detected in the collected specimens using thin-layer chromatography. The characteristics of the lichen distinguishing it from others in Astrothelium are its - ascomata that have an exposed blackish area around their ostioles; the presence of two ascospores per ascus, and the dimensions of the spores.