Porpidinia brevispora, a new species and the second representative of the genus Porpidinia (Lecideaceae, Lecanorales) from the Russian Far East

Porpidinia brevispora sp. nov. from Shikhote-Alin Range, Primorye Territory, Russian Far East is described and illustrated. The new species resembles Porpidinia tumidula morphologically, but is distinct in its spherical to ellipsoid, significantly smaller ascospores that do not overlap in size with those of P. tumidula, as well as a lower hymenium with paraphyses embedded into hyaline gelatinous envelopes, up to 5 mu m wide. Porpidinia brevispora inhabits carbonate rocks at low elevations.