Psoroma urupukapukianum sp. nov. and squamulose Pannaria lichen species in Aotearoa / New Zealand

Psoroma urupukapukianum is described from Urupukapuka Island in the Bay of Islands, Te Tai Tokerau / Northland, Aotearoa / New Zealand based on two herbarium collections made in 1980. It has recently been sought at its type locality without success. The species is corticolous and squamulose, developing into a crust of gymnidia, where c. 3/4 represent the chloromorph and the remaining parts are conspicuous cephalodia with the same external morphology as the chloromorph. The species lacks lichen substances by thin layer chromatography (TLC) and the asci have apical IKI+ structures like other Psoroma species, but the ascospores differ in having long-apiculate perispores. The new species is hypothesised to represent a separate lineage in Pannariaceae, but fresh material for molecular phylogenetic analysis is needed. Psoroma caliginosum and P. melanizum are both newly treated here as synonyms of Pannaria pholidotoides described from the Otago / Ōtakou area. There is also still another unnamed species and an unresolved name from this area. The ascospores of Pannaria pholidotoides have a gibbose perispore, contrasting the long-apiculate perispores of the related species P. implexa. Knowledge of perispore morphology is decisive for identifying squamulose Pannaria species.