Rare and Little-Known Species of Fungi in the “Herbarium of Epixylic Fungi, Algae and Lichens of the St. Petersburg State Forest Engineering University Named After S.M. Kirov” (SPFUE). 1. Melanconis alni, Illosporiopsis christiansenii, Puccinia phragmitis

This article offers an in-depth exploration of the rare and little-known fungal species recently added to the collections of the “Herbarium of epixylic fungi, algae and lichens of the Saint Petersburg State Forest Technical University named after S.M. Kirov” (SPFUE). The acquisitions, made in 2025, contribute significantly to the herbarium’s growing repository of materials. Duplicate specimens were also transferred to the mycological herbarium of the Komarov Botanical Institute (LE F). The herbarium itself was founded in October 2024 with the objective of organizing materials that have been accumulated since the mid-20th century. Central to this foundation are the works and collections of prominent phytopathologists such as A.T. Vakin (1903–1966), I.I. Minkevich (1931–2017), and G.I. Zarudnaya. Covering a distinct thematic niche, the herbarium primarily focuses on fungi and lichens associated with the bark of living trees as well as unfallen and freshly fallen terminal branches. While the herbarium also includes powdery mildew fungi and leaf-spot-causing species on one hand, and tinder fungi on the other, these are less prominently represented. Beyond fungi, the collection houses epiphytic lichens and aerophytic algae, adding further depth to its biological diversity. Highlighting exceptional acquisitions from 2025, the article delves into detailed ecological, morphological, and distributional notes on three noteworthy species: Melanconis alni, Illosporiopsis christiansenii (Ascomycota), and Puccinia phragmitis (Basidiomycota). Additionally, insights into herbarium specimens stored at both LE F and SPFUE are provided, enhancing understanding of their scientific significance.