Byssoloma llimonae, a new species described from NE Spain, Madeira and the Canary Islands (Gomera, La Palma and Tenerife), is a mostly corticolous species, closely related to the more widespread and usually foliicolous Bapalmuia kakouettae (=Byssoloma aptrootii). The generic position of this group of species within the Pilocarpaceae is still unclear. The new combination Byssoloma kakouettae (Sérus.) R. Lücking & Sérus. is introduced.