Taxonomy and mycorrhizal status of Japanese entlomatoid fungi associated with rosaceous and ulmaceous plants were studied. Entoloma saepium and E. clypeatum f. hybridum were newly recorded from Japan. Entolomatoid fungi were not ectomycorrhizal. Transmission electron microscopy of the mycorrhizas suggested destructive infection of the fungal hyphae to the root cells and their collapse near the tip of the stele.