The name Vaucheria compacta var. dulcis is based on 1974 Latin diagnosis and validated here by the type indication in connection with new records of the alga from the Gulf of Finland. The holotype is a specimen identified by J. Simons and stored in the Leiden herbarium of the Naturalis Biodiversity Center (L). The Baltic Sea specimens match the diagnosis in the key feature, the morphology of antheridia.

The paper presents the first record for Russia of one species of ascomycota fungus, first records for the Republic of Belarus of one species of siphonous yellow-green algae and three species of lichenicolous fungi, first records for Kazakhstan and Uzbekistan of two and one species of lichens, respectively, and of first records for regions of Russia: one red alga for the Leningrad Region, one cyanobacteria for St. Petersburg, ten chrysophyte algae for the Leningrad Region, Komi Republic and Republic of Bashkortostan, one charophyte alga for the Yamal-Nenets Autonomous Area, one species of haptophyte algae for the Irkutsk Region, two species of siphonous yellow-green algae for the Chukotka Autonomous Area and Magadan Region, one species of rust fungus for the Komi Republic, seven lichenicolous fungi for the Murmansk and Tver regions, including one species new for Russia, six species of basidiomycetes for the Altai Territory, Republic of Tuva, and Yaroslavl Region; 25 species of lichens for the Amur, Murmansk, Tyumen regions, republics of Altai, Buryatia, Karelia, Komi, Tuva, Altai, and Krasnoyarsk territories, one species of liverwort for St. Petersurg, 13 species of mosses for the Penza, Tambov, Tula, Tyumen regions, Republic of Dagestan, and Nenets Autonomous Area, including one species new for Siberia. Data on their localities, habitats, distribution are provided. The specimens are kept in the herbaria AA, ALTB, GSU, HERZ, IBIW, KPABG, LE, LECB, MIRE, MSK, MW, NSK, ORIS, PKM, PZV, SYKO, TOB, UUH, VU, in the algological collection in the Laboratory of Cell Ultrastructure of the Limnological Institute SB RAS (LIN). Sequences of the 16S rRNA gene of the cultivated strain of a cyanobacterium and sequence of ITS1-5.8S-ITS2 nrDNA region of some specimens of fungi have been deposited in the GenBank (NCBI).

Actinella brasiliensis, a rare diatom for Russia, was first found in Yakutia. As previous detailed studies of this species using SEM are limited, we provide an amended description of its morphology, as well as a comparison of our data with the results of previous studies. Lectotype of the species based on original figure in Grunow’s protologue designated in this article. Based on morphometric and morphological similarity, we propose to consider A. brasiliensis var. curta and A. brasiliensis var. cuneata as synonyms of the type variety. The distribution of the species in Russia is expanded.

The article is dedicated to Victor Dmitrievich Pisarzhevsky, the author of the first published list of lichens of Russia, compiled by him based on publications issued before 1897. The article acquaints a reader with this little-known work, which nevertheless played a certain role in the development of lichenology in our country at its initial stage. The fate of its author— undoubtedly a gifted researcher, was nevertheless sad.

The middle Sikhote-Alin is a huge land located in Pacific Asia between 45°N and 48°N. It covers ca. 60000 km2. The liverwort checklist of this territory was completed based on our own field research and literature sources data; it contains 159 species, one subspecies, and one variety. Previously available information on liverworts for this area, with a few exceptions, originates from the Sikhote-Alin Biosphere Reserve only. The studies conducted in 2017, 2019, and 2021 in four ‘local’ floras have revealed 73 taxa new for the area; nine among them are new for the Sikhote-Alin Mts. (Anastrophyllum assimile, Calypogeia sphagnicola, Cephaloziella arctogena, Cladopodiella fluitans, Fuscocephaloziopsis loitlesbergeri, Herbertus arcticus, Lophozia murmanica, Mylia anomala, Scapania parvifolia var. grandiretis). Abovementioned taxa and Anthelia juratzkana, Apotreubia nana, Cephaloziella rubella var. bifida, Frullania subarctica, Fuscocephaloziopsis pleniceps, Scapania gymnostomophila, in total 15 taxa, are new to the Primorye Territory. The liverwort flora of the Sikhote-Alin Biosphere Reserve was supplemented by 31 species. Thirty-nine liverwort species are listed for the first time for Bikin National Park as the first report of liverworts for the protected territory. The completely new information was collected for two more local floras considered in the present account. For several newly recorded species in the Sikhote-Alin (arctic-montane Cephaloziella arctogena, Frullania subarctica, Herbertus arcticus, arctic-boreal Mylia anomala, boreal Cladopodiella fluitans, Fuscocephaloziopsis loitlesbergeri), the middle Sikhote-Alin is the southern limit in their distribution in mainland Pacific Asia. On the contrary, no liverwort species have the northern limit in their distribution in the middle Sikhote-Alin.

A new species of Cribraria, described herein as С. arachnoidea, was discovered in the southern part of European Russia (the village of Kanevskaya in the Krasnodar Territory). The two specimens upon which the new species is based were obtained in moist chamber cultures, and the sporocarps developed on the dead wood of undetermined deciduous trees. The sporocarps and spores were examined by light and scanning electron microscopy. The main diagnostic morphological characters of Cribraria arachnoidea are the deep violet color of the small sporocarps, relatively short stalk (no more than twice the diameter of the sporotheca), small calyculus, irregular and flat nodes of the peridial net, and the angular spores. Micrographs of all relevant features are presented.

Metacalypogeia cordifolia is recorded for the first time for the Republic of Sakha (Yakutia) from the Udokan Range. The species was found in the shaded narrow with nearly vertical walls gorge, about 1.5 m wide and 2–3 m high, that accumulates snow, covering the plants in winter and has a seepage, watering the plants in summer. It is the northernmost mainland record of M. cordifolia. The identification is confirmed by obtained complete trnL-F cpDNA sequences corresponding to available sequences of M. cordifolia from the Russian Far East and Japan. The description of collected plants, their photomicrographs, and data on morphological variation, ecology, and distribution of M. cordifolia are provided. The key to distinguish M. cordifolia from morphologically similar northern taxa is presented. Differentiation of the genus from morphologically similar representatives of the genera Bazzania, Eocalypogeia, Calypogeia, Mnioloma, and Protocalypogeia is discussed. A joint analysis of bioclimatic data and habitat conditions, along with the absence of traces of glaciation at the place of gathering the species, indicate that it is a refugium. Metacalypogeia cordifolia in the Udokan Range appears to be an Eopleistocene relic.

Eight Hebeloma specimens from the high-altitude zone of Altai Mountains (West Siberia) were analyzed using morphological and molecular methods. Three species were identified (H. alpinum, H. dunense, H. excedens), including the previously unreported in Russia species H. excedens. The detailed morphological description and ecological data on H. excedens based on the studied collections are provided.

At the territory of the Lebyazhe City Forest Park (Kazan), 176 species were identified, of which 160 are lichens, nine are lichenicolous fungi, one is a facultatively lichenicolous, and six are saprotrophic non-lichenized fungi. Of these, 46 species are new to the Republic of Tatarstan, including the lichenicolous fungus Epithamnolia xanthoriae is reported for the first time for the Central European Russia. New habitats of protected in Tatarstan lichen Cresponea chloroconia were found. Most of the newly reported species are mainly widespread lichens in European Russia, which indicates that the lichen biota of Tatarstan is poorly investigated.

Information on the type material of the name Sporopodium caucasicum Elenkin et Woron. (≡ Gyalectidium caucasicum (Elenkin et Woron.) Vězda), stored in the lichenological herbarium of the Komarov Botanical Institute (LE L), is provided. The lectotype of the name is designated.