The article presents updated information on the occurrence of Entoloma conferendum in Poland. The species has been confirmed at no fewer than 132 sites across the country, spanning a wide range of habitats, including approximately 26 forested environments (accounting for 73.5% of classified records) and 11 non-forested ones (21% of classified records). New localities are reported from the Śnieżnik Massif in southwestern Poland, discovered during mycological research conducted in semi-natural montane grasslands maintained through traditional agricultural practices such as extensive mowing and grazing. The article includes descriptions and illustrations of the morphological features of the collected basidiomata. Additionally, the delimitation of E. conferendum is briefly discussed, along with insights into the species’ ecology and distribution in Poland. Particular attention is given to the historical misapplication of the name Hyporrhodius pascuus (Pers.: Fr.) J. Schröt. and its synonyms in Polish mycological literature. Based on a detailed analysis of Schröter’s original description and the examination of specimens he identified, it is concluded that H. pascuus is a misapplied name, now correctly attributed to Entoloma conferendum (Britzelm.) Noordel.

The first checklist of lichens occurring in the Ujście Warty National Park and its buffer zone is presented. The list is based primarily on the research conducted in years 2022–2024, but incorporates also the earlier literature data. During the research 138 lichen taxa were recorded, including 122 within the boundaries of the national park and 81 in its buffer zone. They represent various habitat groups: epiphytes (63 species), epixyles (59 species), epigeits (31 species), epiliths (39 species, both calcicolous and silicicolous) and species found on metal (20 species). A characteristic feature of the analysed lichen biota is the dominance of taxa typical of highly eutrophic habitats.

Fungi, as living organisms, offer a vast potential for synthesizing natural compounds. Many of these compounds are highly valued as nutraceuticals and pharmaceuticals due to their medicinal properties and economic significance. Fungi are known to produce a wide range of secondary metabolites with bioactive properties, including antimicrobial and antioxidant activities, which contribute significantly to human health and well-being. In an age, when microbial antibiotic resistance increases, searching for new therapies to combat bacterial infections is in demand. Due to their ubiquitous nature, fungi are often chosen as promising candidates in the search for new antimicrobial agents. Among them, the genus Xylaria stands out. Widely distributed in subtropical and temperate regions, Xylaria species occupy various ecological niches, including decaying wood, living plant tissues as endophytes, and even the guts of termites, making their isolation both challenging and intriguing. This article reviews the literature on antibacterial compounds derived from Xylaria species, with a particular focus on those with confirmed antibacterial activity and potential applications in therapeutic protocols.

Parmelia submontana is quite a rare epiphytic lichen in both Poland and central Europe. In Poland, it grows mainly in the mountains and in the northern part of the country. We found eight new localities of P. submontana, in northern and southwestern Poland. We report it here as a new species for Wigry National Park. Distribution of the species in Poland is presented on the map.

The saprotrophic fungus <i>Phaeocalicium populneum</i> was noted from Poland only from one confirmed locality at the end of the 19th century, from the vicinity of Żagań (SW Poland). A new locality of this species is presented, which was found in 2017 on the bark of <i>Populus nigra</i>, within the Puszcza Darżlubska Forest in northern Poland. The species is common in Europe, and we consider that <i>Ph. populneum</i> is not rare in the country,

<i>Sarcosoma globosum</i> (witches cauldron) is a threatened species of pezizomycete (Ascomycete) fungus primarily documented in spruce (<i>Picea</i> spp.) forests of northern Europe. Sporadic reports of <i>S. globosum</i> have been reported in eastern North America, but it has been suggested that these may have been misidentified. Importantly, the species has not been officially reported in western North America. Following reported observations of <i>S. globosum</i> in British Columbia, Canada, we conducted a citizen science survey to document its distribution and occurrence over four consecutive years (2021–2024). Firstly, we verified that sporocarps collected in eastern (New Brunswick) and western (British Columbia) Canada were <i>S. globosum</i> via the morphological, ecological, and phylogenetic (analysis of the ITS gene) species concepts. Secondly, <i>S. globosum</i> was documented in all four years of the survey over a wide geographical area in British Columbia. Finally, we mapped the Canadian distribution of <i>S. globosum</i> based on publicly available databases. The species appears to be found across Canada (British Columbia to Nova Scotia), where spruce-dominated forests are present, supporting the current Canadian national conservation status of ‘Apparently Secure/Secure’ (N4, N5). However, its habitat remains threatened by climate change, forest fires, and logging activities that may limit its future geographical distribution. This study presents the first documented occurrence of <i>S. globosum</i> in British Columbia, expanding the species’ known distribution to western Canada.

The paper presents the state of knowledge of the lichen biota of the “Mszar” and “Redykajny” nature reserves, located in the “Las Miejski” urban forest complex in Olsztyn (north-eastern Poland). The results of the inventory conducted in 2024 are described, which are compared with published data collected in 1999–2001. So far, a total of 118 lichenized and three non-lichenized fungi have been identified in this area. Recent studies did not confirm the occurrence of 18 species, but at the same time showed 32 species new to the study area. The article discusses possible causes of changes in the species composition of the lichen biota over almost 25 years and the effectiveness of various methods of collecting data in the field. The results prove that both reserves are still important refuges of forest lichen biodiversity on a scale larger than just the area of Olsztyn’s urban forests.

The material was collected during studies of the vegetation of Kaffiøyra in the course of „Thirteenth Toruń Polar Expedition, Spitsbergen - 1997” of N. Copernici University of Toruń. The studied areas were situated only on moraines, some mountain massif slopes, and all terraces. Samples of lichens were taken from 24 out of 61 total squares with an area of 1 km<sup>2</sup>. In the study area, 12 taxa of the genus <i>Peltigera</i> were noted, including nine new ones to the Kaffiøyra Plain, such as <i>P. aphthosa, P. canina, P. didactyla, P. frippii, P. kristinssonii, P. lyngei, P. neckeri, P. polydactylon, P. ponojensis</i> and three previously noted, such as <i>P. leucophlebia, P. malacea</i>, and <i>P. rufescens</i>. The most frequently recorded species in the study area were <i>P. canina</i> (9 localities), <i>P. malacea</i> (9), <i>P. ponojensis</i> (9) and <i>P. rufescens</i> (9). The greatest species diversity occurred on Waldemar Glacier Sander. As many as 10 species of <i>Peltigera</i> genus were recorded there. An average of five species per square were recorded in that region.

The presence of various crystal forms is quite often noticed in lichens from manytaxonomic groups. The crystalline deposit may be linked with the production of secondary metabolites or metal oxalates as well as to the uptake of calcium carbonate from the host substrate. Although the crystals are clearly visible under a microscope employing polarized light, their detailed determination is very difficult without the use of specialized equipment and analytical methods. On the other hand, it is not uncommon for the surface of lichen thalli to be covered with apparent pruina, which is formed by masses of calcium oxalate crystals. Regardless of their origin and distribution, crystalline products can perform an important functional role and enhance the adaptation of a given species to a specific habitat. Moreover, the presence and kind of crystals can be species-specific or characteristic of a certain group of species and, therefore, may constitute a useful diagnostic feature. We intended to examine the extent to which standard methods used in lichen taxonomy, such as solubility tests in chemical reagents, allow for the basic determination of crystals. We indicate the basic differences between various crystal deposits that can be observed inside or outside the lichen thallus. The presented results are based on examining selected specimens representing various lichen genera.

New lichenological data of thirteen rare, protected, and noteworthy lichen species found in Central and North-Eastern Poland are presented. One species – <i>Absconditonia rubra</i> is new to Poland and six of them – <i>Biatora veteranorum</i>, <i>Normandina pulchella</i>, <i>Lepraria umbricola</i>, <i>Micarea isidioprasina</i>, <i>M. soralifera</i>, <i>Mycoblastus sanguinarius</i>, and <i>Trapelia involuta</i> are new to Central Poland. In addition, new localities of five rare and protected lichen species – <i>Cetraria ericetorum</i>, <i>Chaenotheca brachypoda</i>, <i>Cladonia stellaris</i>, <i>Parmelia submontana</i> and <i>Peltigera malacea</i>, are also presented.