Psoroma capense and P. esterhuyseniae (Pannariaceae), two new alpine species from South Africa

Abstract

The new species <i>Psoroma capense</i> and <i>P. esterhuyseniae</i> are described from four alpine localities in the Western Cape Province of South Africa and are the only known <i>Psoroma</i> species from Africa. The specimens were all collected from moist sites near watercourses, on cool and mostly south-facing cliffs. <i>Psoroma capense</i> resembles <i>P. tenue</i> in gross morphology but differs in the ascending thallus squamules, lack of secondary compounds and short-ellipsoid to ovoid ascospores. However, a phylogenetic analysis involving the markers ITS, nucLSU, mtSSU and Mcm7, comparing the only recent collection of <i>P. capense</i> with previously published sequences, shows that it belongs to the <i>P. hypnorum</i> lineage, with no known, closely related species. <i>Psoroma esterhuyseniae</i> resembles <i>P. hypnorum</i> but has subglobose to short-ellipsoid ascospores without apical perispore extensions. The two species are thought to have evolved from one or two long-distance dispersal events during the Pleistocene.