[Pyrenula occidentalis found in Sweden.] The lichen Pyrenula occidentalis (R.C.Harris) R.C.Harris is reported for the first time from Sweden. It was found on smooth bark of Sorbus aucuparia, Populus tremula, Corylus avellana and Quercus sp. in a moist and shaded deciduous forest in central Bohuslän, SW Sweden. The locality is described and the ecology and distribution of the species is briefly outlined. P. occidentalis is an interesting addition to the oceanic lichen flora of southern Sweden.