The Bažantník Nature Reserve (14.06 ha; alt. 256–269 m) preserves a deciduous lowland forest with c. 240-year old oak trees. The locality is very rich in phorophytes (>20 species) but strongly affected by acid rain in the past. During a survey in 2022, 94 lichen species and 8 non-lichenised fungi were recorded in the reserve. This number includes 17 species of calicioid (= pin-head) lichens and fungi. Most of the rare lichens occur on old oaks and their snags. In the area of Český ráj (Bohemian Paradise) and its surroundings, the reserve belongs to the most valuable localities for epiphytic and epixylic lichens. Bacidia arceutina, Biatora veteranorum, Buellia schaereri, Calicium adspersum, Chaenotheca brachypoda, C. chlorella, Chaenothecopsis nigra, Lecidella subviridis, Leptorhaphis atomaria, Ochrolechia arborea, Rinodina freyi, and Sclerophora pallida represent the most valuable records. Identifications of three specimens are supported by molecular ITS or mtSSU data, including one potentially undescribed Psoroglaena species. Key words: biodiversity, calicioid lichens and fungi, natural lowland forests, oak trees.