Nivicolous myxomycetes from the Pyrenees: Notes on taxonomy and species diversity. Part 1 Physarales and Trichiales

(ENG) The results of a study of 20 species of myxomycetes, belonging to the orders Physarales and Trichiales and collected in nivicolous locations of the Pyrenees, are given. Description of the species from the Diderma niveum complex are provided and supplemented with a discussion about their position in the complex. A taxonomic study of Diderma peyerimhoffii, based on a detailed SEM and X-ray analysis of its wall structure, is included. Additionally, a comparative study on the chemical composition of peridium of representatives of the genera Diderma and Lepidoderma is tested in order to find inter- and intra-generic differences. The conspecificity of Lepidoderma carestianum and L. granuliferum is argued based on observations on the material from the Pyrenees. The distribution of all species in Spain is summarized. Eight species are reported for the first time from the Pyrenees, two taxa are new to Spain and two others are new to Andorra.