Astrothelium ultralucens
Astrothelium ultralucens is a species of corticolous lichen in the family Trypetheliaceae. Found in Venezuela, it was formally described as a new species in 2016 by André Aptroot. The type specimen was collected by Harrie Sipman along the Carapo River at an elevation of. The lichen has a smooth, somewhat shiny pale greenish grey thallus that covers an area of up to. Its ascospores are hyaline, spindle-shaped with three septa and dimensions of 105–130 by 35–42 μm. Astrothelium ultralucens contains lichexanthone, a lichen product that causes the pseudostromata and the thallus to fluoresce yellow when lit with a long-wavelength UV light, although the thallus only weakly.