Tomentella alpina and other tomentelloid taxa fruiting in a glacier valley

Tomentella is a genus of resupinate basidiomycetes usually fruiting on rotten wood. Ecological studies based on molecular methods have reported many Tomentella species as mycobionts of alpine ectomycorrhizal plants, thus highlighting their importance for plant establishment and development under extreme conditions. For the first time, we report fruiting of eight tomentelloid species in an alpine site, and describe Tomentella alpina as a new species. In the rDNA ITS phylogeny, Tomentella alpina forms a distinct clade in the T. stuposa complex, from which it can be clearly separated based on spore size and shape. Closely related taxa are briefly described, and synonymy of Tomentella fungicola with T. stuposa is rejected. Tomentella alpina was found to be one of the most important mycorrhizal partners of Kobresia myosuroides, Bistorta vivipara and Salix herbacea at this alpine site. The mutualistic association with plants is a very successful life strategy for Tomentella spp. growing in primary successional habitats, where the lack of organic matter is generally a growth-limiting factor.