Astrothelium laevithallinum
Astrothelium laevithallinum is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae. Found in Brazil, it was formally described as a new species in 2016 by Robert Lücking, Matthew Nelsen, and Marcelo Marcelli. The type specimen was collected by the first author from the Santuário do Caraça (Reserva Particular do Patrimônio Natural, Minas Gerais) at an altitude between ; there, in Atlantic Forest, it was found in a forest remnant near a waterfall. The lichen has a smooth to uneven, green thallus that covers areas of up to  in diameter. The species epithet laevithallinum alludes to the contrast between its smooth thallus and the  thallus of its phylogenetically distinct but close relative, Astrothelium endochryseum. The characteristic of the lichen that distinguishes A. laevithallinum from others in genus Astrothelium is the smooth thallus. References

laevithallinum
Lichen species
Lichens described in 2016
Taxa named by Robert Lücking
Lichens of Brazil