First Russian records of Stemonitis rhizoideipes and Fuligo aurea, and newly observed morphology for Comatricha anomala

Three rare species of myxomycetes have been collected from Khanty-Mansi Autonomous Okrug–Yugra, Russia. Stemonitis rhizoideipes and Fuligo aurea were recorded for the first time in Russia and for the second time in extratropical Eurasia, and Comatricha anomala was recorded from a second Russian location. Thirty-three S. rhizoideipes specimens were isolated from bark of Abies sibirica, Picea obovata, and Pinus sibirica in moist chambers, while F. aurea plasmodiocarps were retrieved from A. sibirica bark in one Petri dish. We publish an emended description of Comatricha anomala after discovering new morphological features. Light and scanning electron micrographs and comparisons with morphologically similar taxa are presented for the three species.