Samsoniella is a very important fungal resource, with some species in the genus having great medical, economic and ecological value. This study reports five new species of Samsoniella from Yunnan Province and Guizhou Province in Southwestern China and Dole Province in Vietnam, providing morphological descriptions, illustrations, phylogenetic placements, associated hosts and comparisons with allied taxa. Based on morphological observations and phylogenetic analyses of combined nrSSU, nrLSU, tef-1α, rpb1 and rpb2 sequence data, it was determined that these five new species were located in the clade of Samsoniella and different from other species of Samsoniella. The five novel species had morphologies similar to those of other species in the genus, with bright orange cylindrical to clavate stromata (gregarious). The fertile part lateral sides usually had a longitudinal ditch without producing perithecia, and superficial perithecia. The phialides had a swollen basal portion, tapering abruptly into a narrow neck and oval or fusiform one-celled conidia, often in chains. The morphological characteristics of 23 species in Samsoniella, including five novel species and 18 known taxa, were also compared in the present study.
Keywords: isaria-like fungi; micromorphology; phylogenetic analyses; taxonomy.