Pannaria leproloma is shown to be a New Zealand endemic, and is characterized by coarse isidiomorphs/isidia, a high frequency of apothecia and the presence of two cytotoxic scabrosin esters, previously unknown from Pannariaceae, and present in 40 of the samples studied. It is not a member of the Pannaria sphinctrina group, as previously thought. It has frequently been confused with a related, finely sorediate, very sparingly fertile species, which lacks scabrosin esters in more than 99 of the specimens studied. This latter species is widely distributed both in southern South America (where it is one of the most common corticolous lichens), south-eastern areas of Australia and in New Zealand. It was originally described as Psoroma isidiosum, but had to be renamed when transferred to Pannaria, and is here named Pannaria farinosa.