Gangliostilbe costaricensis sp. nov., isolated from rotten wood, is de
scribed and illustrated. This fungus is mainly distinguished by its pa
le brown, 3-septate, broadly obovate conidia. A dichotomous key to spe
cies of Gangliostilbe and some notes on similar genera are given. Furt
hermore, 22 species of hyphomycetes are newly reported from Costa Rica
.