New record of Agrocybe firma (Strophariaceae, Agaricales) in Korea

Globally, approximately 100 Agrocybe species have been documented; however, only ten have been identified in Korea. To bridge this disparity in biodiversity records, we conducted a survey of indigenous fungi in Korean National Park, South Korea, in 2021 and 2022. All Agrocybe specimens collected during the survey were identified based on morphological characteristics and Internal Transcribed Spacer (ITS) region sequences of rDNA. Three species were identified: Agrocybe arvalis, Agrocybe firma, and Agrocybe praecox. Among them, A. firma was a previously unrecorded species in Korea, based on a combination of detailed mor- phological characterization and ITS sequence phylogenetic analysis. Detailed macroscopic and microscopic morphological features of the newly discovered species are described herein. This study contributes to expanding the diversity of Agrocybe in Korea by elu - cidating the morphological features and phylogenetic relationships of previously unrecorded species and their related species.