Five species of macrofungi (Basidiomycota) new to Korea

South Korea has more than 3300 islands, each with a unique ecosystem and biodiversity distinct from the mainland. These islands are rich in biological resources of high conservation value, with new and previously undocumented species continually being discovered. However, research on fungal diversity and distribution in these island areas remains limited. Therefore, a mycological investigation was conducted in 2023 in three island areas in Southwestern Korea. Several samples of wild mushrooms were collected and subjected to DNA extraction, polymerase chain reaction, and phylogenetic analysis, resulting in the identification of five specimens from different species. Based on phylogenetic analysis and morphological examination, five species—Agaricus deardorffensis, Agaricus melanocarpus, Boletellus aurocontextus, and Strobilomyces seminudus, Xeromphalina tenuipes—were reported for the first time in Korea. This study presents the morphological descriptions, color photographs, and phylogenetic analyses of these species.