Schistidium foraminis-martini sp. nov. (Grimmiaceae), a high mountain calcicole from the European Alps molecularly related to S. agassizii

Schistidium foraminis-martini is described as a new species from the Austrian and Swiss Alps. The taxon is characterized by a warm brown coloration, ovate, concave and muticous leaves with rounded apices, ellipsoid capsules, constricted at mouth, the presence of stomata and a reduced, truncate peristome. Based on sequences of the ITS region the new species is phylogenetically rather isolated, exhibiting the closest relationship to S. agassizii which shares the muticous leaves but differs in having narrowly lingulate-lanceolate, almost flat leaves, cyathiform capsules and a perfect peristome. Schistidium foraminis-martini grows on moist calcareous rocks in the alpine and nival belt.