The paper is dedicated to 90th birthday of Teuvo Tapio Ahti — worldwide famous Finnish scientist whose impact to Russian lichenology is hard to overestimate. Special attention is paid to personal impressions of the authors from the communication with outstanding colleague in course of joint studies of the lichen biota of North-West Russia.

The ultrastructure of the silica scales and bristles of two morphologically similar taxa, Mallomonas multiunca var. multiunca and M. multiunca var. pocosinensis, was compared. Based on the revealed differences in the morphology of scales and bristles, the taxonomic status of the species M. multiunca var. pocosinensis was revised and a new taxonomic combination, Mallomonas pocosinensis comb. stat. nov., was proposed. Аn updated description and original SEM micrographs are provided.

The paper is dedicated to the jubilee of worldwide famous Finnish lichenologist, Professor Teuvo Ahti. Impressions of the meeting in September 2016 are described.

The paper contains the first data on the lichen biota of Broutona Island, one of the most inaccessible small islands of the Kuril Ridge. Information on the findings of 31 species of lichens first discovered on the island is presented. Among them, Peltigera venosa is a new species for the Sakhalin Region, Stereocaulon alpinum is new for the Kuril Islands, and Bryocaulon pseudosatoanum is listed in the Red Data Book of Russia and the Red Data Book of the Sakhalin Region. Information on the habitats of these species on Broutona Island, as well as their distribution in the Kurils and neighboring regions, is provided.

Here we provide a key for the identification of 39 crustose Teloschistaceae species in soil communities in Russia growing on soil, bryophytes, plant debris, twigs of small shrubs, and on thalli of other lichens.

The first records for Russia of one species of siphonous yellow-green algae, ascomycete, and lichenicolous fungus, and the first records for regions of Russia: nine species of siphonous yellow-green alga for the Arkhangelsk, Astrakhan, Moscow, Volgograd regions, two diatom species for the Tyumen Region, nine species of basidiomycetes for the Novgorod, Tomsk regions, and the Republic of Tuva, three species of lichenicolous fungi for the Orenburg Region and Krasnoyarsk Territory, 23 species of lichens for the Arkhangelsk, Irkutsk, Murmansk, Sakhalin regions, Altai, Buryatia and Komi republics, Altai and Khabarovsk territories, 15 species of mosses for the Arkhangelsk, Magadan, Orel, Voronezh regions, Kamchatka Territory, Republic of Tuva, and St. Petersburg, one species of liverwort for the Krasnoyarsk Territory are presented. The data on their localities, habitats, distribution are provided. The specimens are kept in the herbaria ALTB, AR, H, IBIW, IRK, KPABG, LE, MAG, NSK, PTZ, PZV, SMR, SYKO, VU, in the diatom collection of the Timiryazev Institute of Plant Physiology RAS, the Tobolsk complex scientific station RAS or Vaucheria collection of the Laboratory for Algology at the Papanin Institute for Biology of Inland Waters RAS. Sequences of ITS1-5.8S-ITS2 nrDNA regions of some specimens of fungi and ITS1-2 nrDNA and trnL-F cpDNA of one liverwort have been deposited in the GenBank.

Cadophora qinghaitibetana is isolated from soil near glacier at the mountains of the Caucasus (Tsei Gorge, the Main Caucasus Range, Republic of North Ossetia – Alania). Macro- and micromorphology of the isolate along with partial sequences of the internal transcribed spacer of rDNA (ITS1-5.8S-ITS2) are studied. The observed micro- and macromorphology of isolate NN-22 from Tsei Gorge corresponds to the micro- and macromorphology of C. qinghaitibetana from soils and melt water from the Yulong and Baima Mountains located on the Qinghai-Tibet Plateau, i. e., Tibetan Plateau (China), but the maximum growth temperature is higher. As a result of our study, we detected C. qinghaitibetana in the Caucasus and Russia for the first time. Our study shows that C. qinghaitibetana is a species found in both the Tibetan Plateau and the Caucasian mountains.

The data on 79 species of aphyllophoroid fungi of the Mudyugsky Reserve, which is located near the mouth of the Northern Dvina River in the Primorsky District of the Arkhangelsk Region, are reported. Three species are new to the Arkhangelsk Region (Lindtneria leucobryophila, Peniophora piceae and Phlebia albomellea), all of them and Jaapia argillacea are known for the Arkhangelsk Region only from this area. Within the territory, there are three species listed in the Red Book of the Arkhangelsk Region and nine indicator species, of which seven are indicators of oldgrowth and two of virgin spruce and pine forests.

During the study of the lichen flora of the Utrish Nature Reserve (Abrau Peninsula, Krasnodar Territory), a Mediterranean-Atlantic lichen species Bactrospora patellarioides was identified for the first time for Russia and the Caucasus based on morphological and anatomical characteristics. This species grows on the trunk of Juniperus excelsa in the sub-Mediterranean xerothermic undisturbed pistacia-juniper community on the Black Sea coast. The species was previously known from the Mediterranean regions of Europe, Western Asia, North Africa, and is also known from Macaronesia and Western North America. Detailed description, habitat characteristics, ecology, and general distribution of species are presented. Notes on the genus Bactrospora are given, and a key to the Russian species (B. brodoi, B. dryina and B. patellarioides) is provided.

The revealed lichen diversity of the Lisinsky Protected Area counts 296 species, including 262 lichens, 20 lichenicolous fungi, and 14 non-lichenized saprobic fungi. The species Normandina chlorococca is reported for the first time for Russia, Gyalidea minuta, Lecanora substerilis, Lecidea betulicola, Vezdaea stipitata are new to the North-Western European Russia, and Fellhanera bouteillei is new to the Leningrad Region. The territory is represented by a significant diversity of lichens and related fungi, including 28 protected species, indicator species and habitat specialists of biologically valuable forests. The communities formed by old-growth spruces and aspens are of greatest value for the conservation of lichen biota, as far as in such biotopes the species associated with biologically valuable forests are most often found in complexes.