Marasmioid and gymnopoid fungi of the Republic of Korea. 8. Gymnopus section Impudicae

Collections of Gymnopus sect. Impudicae from the Republic of Korea are evaluated. Three recorded species (G. densilamellatus, G. similis, and G. variicolor) are described as new for the science: Gymnopus densilamellatus is macroscopically characterized as having a brown to reddish brown, sometimes pale ochraceous and later whitish pileus and crowded lamellae. Gymnopus similis has an ochraceous-grey, brownish orange or brownish red pileus, and moderately distant, whitish, later dirty yellowish, greyish, or brownish orange or light brown lamellae. Gymnopus variicolor is characterized by a reddish brown, brownish red or violet brown pileus drying-up to light brown or brown, greyish brown or greyish red, later pale brownish orange lamellae, and greyish brown or greyish red pileus, grey-brown, light to reddish brown in upper part. Gymnopus dysodes is recorded for the first time in Korea. The morphological characteristics of the species are provided with a key for their identification. The taxonomic positions of all taxa are confirmed by the DNA sequences of the internal transcribed spacer region and the large subunit of ribosomal rRNA gene.