Two New Amanita Species in Section Amanita from Thailand

Based on a survey of macro-fungi in northern and northeastern Thailand, nine samples collected in 2020 are identified as Amanita and introduced here as two new species, Amanita kalasinensis and A. ravicrocina. Typical macro- and microscopical characteristics indicate that both of these two species belong to Amanita section Amanita, but differ from other currently known species. Amanita kalasinensis is characterized by having a greyish yellow pileus covering with a conical to granuliform, yellowish white volval remnant; the presence of clamps; and a broadly ellipsoid to ellipsoid basidiospore. Amanita ravicrocina is characterized by having a brown to greyish orange pileus covering with a patchy, white volval remnant; a collar-like volval remnant on the stipe; and a subglobose to broadly ellipsoid basidiospore. Multi-gene phylogenetic analysis of partial nuclear rDNA internal transcribed spacer region (ITS), partial nuclear rDNA large subunit region (nrLSU), RNA polymerase II second largest subunit (RPB2), partial translation elongation factor 1-alpha (TEF1-alpha), and beta-tubulin gene (TUB) also revealed that positions of A. kalasinensis and A. ravicrocina are well-supported within A. section Amanita, but form distinct lineages and do not show any close relationship with any species. The detailed morphological features, line-drawing illustration, and comparison with morphological similar taxa are provided.

Automated summary

Based on a survey of macro-fungi in northern and northeastern Thailand, two new species of Amanita, Amanita kalasinensis and A. ravicrocina, are introduced. These two species belong to Amanita section Amanita and show distinct characteristics from other known species. Detailed morphological features, line-drawing illustration, and molecular analysis support their classification.