Taxonomy of Alnus-associated hypogeous species of Alpova and Melanogaster (Basidiomycota, Paxillaceae) in Europe

Morphological analysis of basidiomata of gastroid Boletales (Alpova and Melanogaster) found in relation with Alnus trees in France revealed the existence of five distinct Alnus-associated species: Alpova alpestris sp. nov., A. corsicus sp. nov., Melano-gaster luteus Zeller, M. rivularis sp. nov., and an unnamed species (Alpova sp. related to the North American A. cinnamomeus). The genus Alpova is here restricted to its original sense, as Alnus-associated species with small spores and pseudoparenchymatic subpellis, and the presence of "buffer cells" in gleba. Phylogenetic position, host specificity and geographical distribution of each species are summarized.