title: NEW SPECIES OF THE GENUS PHYSARUM (MYXOMYCETES = MYXOGASTREA) FOR RUSSIA
abstract: Three new species for Russia: Physarum subnutans, P. gravidum, and P. caesiellum are reported for Russia. For each species, photographs of sporocarps and light and electron microscopic images are provided. The morphology of the specimens belonging to P. caesiellum are also fi ts the description of P. pseudocolumellatum (syn. P. columellatum var. «macrosporum»), but these taxa have never been validly published. For this reason we propose to use the name P. caesiellum for both last taxa. However, 
journal: Byulleten Moskovskogo Obshchestva Ispytatelei Prirody Otdel Biologicheskii