Two new species of Samsoniella (Cordycipitaceae, Hypocreales) from the Mayao River Valley, Guizhou, China Author Chen, Wan-Hao https://orcid.org/0000-0001-7240-6841 Center for Mycomedicine Research, Basic Medical School, Guizhou University of Traditional Chinese Medicine, Guiyang 550025, Guizhou, China Author Liang, Jian-Dong https://orcid.org/0000-0002-3939-3900 Center for Mycomedicine Research, Basic Medical School, Guizhou University of Traditional Chinese Medicine, Guiyang 550025, Guizhou, China Author Ren, Xiu-Xiu Center for Mycomedicine Research, Basic Medical School, Guizhou University of Traditional Chinese Medicine, Guiyang 550025, Guizhou, China Author Zhao, Jie-Hong https://orcid.org/0000-0003-2972-382X Center for Mycomedicine Research, Basic Medical School, Guizhou University of Traditional Chinese Medicine, Guiyang 550025, Guizhou, China Author Han, Yan-Feng https://orcid.org/0000-0002-8646-3975 Institute of Fungus Resources, Department of Ecology, College of Life Sciences, Guizhou University, Guiyang 550025, Guizhou, China swallow1128@126.com text MycoKeys 2023 2023-09-15 99 209 226 http://dx.doi.org/10.3897/mycokeys.99.109961 journal article http://dx.doi.org/10.3897/mycokeys.99.109961 1314-4049-99-209 4F2AA0B5BFD45BAA87D3C496F303D382 Samsoniella vallis W.H. Chen, Y.F. Han & J.D. Liang sp. nov. Fig. 4 Type . China , Guizhou , Qiannan Buyei and Miao Autonomous Prefecture , Duyun City , Mayao River Valley ( 26°22'8.3748"N , 107°23'16.96"E ). On a pupa ( Lepidoptera ) clinging to fallen leaves, 30 July 2022 , Wanhao Chen, GZAC DY0724 ( holotype ), ex-type living cultures, DY07241 . Description. Synnemata arising from every part of the body of the pupa host. Synnemata erect, usually irregularly branched at the apex, conidia in abundance at the apex. Colonies on PDA, attaining a diameter of 31-37 mm after 14 days at 25 °C, white, consisting of a basal felt, floccose hyphal overgrowth; reverse yellowish. Hyphae septate, hyaline, smooth-walled, 2.1-3.0 μm wide. Conidiophores hyaline, smooth-walled, with single phialide or whorls of 2-4 phialides or verticillium-like from hyphae directly, 11.3-22.1 x 1.3-1.4 μm . Phialides cylindrical to ellipsoidal, somewhat inflated base, 7.2-8.1 x 2.8-3.2 μm , tapering to a thin neck. Conidia hyaline, smooth-walled, fusiform to ellipsoidal, 2.3-3.1 x 1.5-2.1 μm , forming divergent and basipetal chains. Sexual state not observed. Figure 4. Samsoniella vallis A infected pupa ( Lepidoptera ) B, C PDA culture plate showing top ( B ) and reverse ( C ) sides of the colony D-M phialides and conidia. Scale bars: 10 mm ( B, C ); 10 μm ( D-M ). Host. Pupa ( Lepidoptera ). Etymology. Referring to its location in Mayao River Valley. Additional material examined. China , Guizhou , Qiannan Buyei and Miao Autonomous Prefecture , Duyun City , Mayao River Valley ( 26°22'8.3748"N , 107°23'16.96"E ). On a pupa ( Lepidoptera ) clinging to fallen leaves, 30 July 2022 , Wanhao Chen, DY 07242 (living culture) ; China , Guizhou , Qiannan Buyei and Miao Autonomous Prefecture , Duyun City , Mayao River Valley ( 26°22'8.3748"N , 107°23'16.96"E ). On a pupa ( Lepidoptera ) clinging to fallen leaves, 4 September 2021 , Wanhao Chen, GZAC DY09109 (specimen), DY091091 and DY091092 (living culture). On a pupa ( Lepidoptera ) clinging to fallen leaves, 4 September 2021 , Wanhao Chen, GZAC DY0909 (specimen) . Remarks. Samsoniella vallis was easily identified as Samsoniella , based on the BLASTn result in NCBI and the phylogenetic analysis of the combined datasets (ITS, LSU, RPB1 , RPB2 and TEF ) (Fig. 1 ) and clustered with S. aurantia in a clade. However, it is distinguished from S. aurantia (phialides: 5-13 x 2-3 μm ; conidia: fusiform or oval, 2-4 x 1-2 μm ) by shorter phialides, smaller fusiform to ellipsoidal conidia. Comparing with the typical characteristics of the known species and the keys of Samsoniella species ( Wang et al. 2022 ), S. vallis has a close relationship with S. coccinellidicola and S. sinensis by absence of sexual state, presence of synnemata and irregularly branched, moderate growth of colony. However, it is distinguished from S. coccinellidicola (phialides: 6.0-14.1 x 1.0-2.0 μm ; conidia: fusiform or oval; host, adults of Coccinellidae ) by shorter phialides, fusiform to ellipsoidal conidia and its pupa host and distinguished from S. sinensis (phialides: 5.6-9.3 x 1.5-2.1 μm , conidia: spherical, elliptical or fusiform) by fusiform to ellipsoidal conidia and shorter phialides.