Letrouitia sp.
Brazil, photo kindly provided by Alfonso Spielmann.
A crustose lichen growing on tree trunks in light forest, with a greenish thallus and orange to rusty brown apothecia. The species look very similar from outside and ascospores have to be examined to recognize the species.

Letrouitia domingensis (Pers.) Haf. & Bellem.
Brazil, Paraná, Rio Iguacu, leg. J. Saödanha 23 [B].
On tree trunk in forest alonf river.
[picture height = 3.5 mm]