Mycelial characteristics of dikaryotic collections of 6 medicinal polypore mushrooms (Fomes fomentarius, Fomitopsis pinicola, Ganoderma adspersum, G. applanatum, G. lucidum, and G. resinaceum) with different geographical origins (Armenia, China, France, Iran, Italy, and Russia) were screened. A total of 42 polypore collections were molecularly identified by sequencing the internal transcribed spacer region of the ribosomal RNA genes' cluster, and a phylogenetic tree was constructed. Morphological characteristics of 37 cultures were observed on agar media (malt extract agar, potato dextrose agar) at different temperatures (25, 30, 35, and 38°C) at a pH of 6.0. Colony morphology, pigmentation of mycelium and agar, mycelial growth rate, in vitro teleomorph formation, and other macromorphological characteristics were thoroughly described and illustrated. Micromorphological features of mycelia, such as different hyphal structures, clamp cells, presence and type of asexual sporulation, chlamydospores, and others were observed. The taxonomic significance of the mycelial characteristics revealed was estimated. The obtained results will assist further biotechnological cultivation of medicinal polypore mushrooms to develop novel health care biotechnological products.