Triseptata sexualis gen. et sp. nov. in Latoruaceae (Pleosporales) Author Boonmee, Saranyaphat 0000-0001-5202-2955 Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand. & School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand. saranyaphat.khag2@gmail.com Author Calabon, Mark S. 0000-0002-6603-1876 Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand. & School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand. mscalabon@up.edu.ph Author Phookamsak, Rungtiwa 0000-0002-6321-8416 Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Science, Kunming 650201, Yunnan, People’s Republic of China. jomjam.rp2@gmail.com Author Elgorban, Abdallah M. 0000-0003-3664-7853 Center of Excellence in Biotechnology Research, King Saud University P. O. Box. 2455, Riyadh 11451, Saudi Arabia. & Department of Botany and Microbiology, College of Science, King Saud University, P. O. Box: 2455, Riyadh, 1145, Saudi Arabia. aelgorban@ksu.edu.sa Author Hyde, Kevin D. 0000-0002-2191-0762 Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand. & Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Science, Kunming 650201, Yunnan, People’s Republic of China. kdhyde3@gmail.com text Phytotaxa 2020 2020-06-11 447 4 252 264 http://dx.doi.org/10.11646/phytotaxa.447.4.3 journal article 10.11646/phytotaxa.447.4.3 1179-3163 13877259 Triseptata sexualis Boonmee & Phookamsak , sp. nov. ( Figs. 2 , 3 ) Index Fungorum number : IF557184, Facesoffungi number : FoF 07230 Etymology:—The specific epithet “ sexualis ” referring to sexual morph. Holotype :— MFLU 11–0002 Saprobic on dried branches of an unidentified plant. Sexual morph : Ascostromata (108–)148–157 µm high × (120–)157–198 µm diam. ( x = 145 × 172 µm, n = 5), immersed to slightly erumpent, visible as black spots, single or clustered, scattered or gregarious, uni- to multi-locular, globose to subglobose, with or without basal stroma, dark brown, obscure ostiole. Peridium 16–26 µm wide, composing several layers of textura angularis , with compressed of dark brown cells. Hamathecium comprising 1.5–2 µm wide, cylindrical, branched, septate, anastomosed, hyaline pseudoparaphyses. Asci 43–60 × 7–9 µm ( x = 52 × 8 µm, n = 20), 8-spored, bitunicate, fissitunicate, cylindrical-clavate, sessile, apically rounded. Ascospores 11.5–15 × 4–5 µm ( x = 13 × 4.5 µm, n = 20), 1–2-seriate, partially overlapping, ellipsoid-fusiform, straight or slightly curved, regularly 3–septate, darkened and constricted at the septa, the second cell from the top slightly wider than the others, asymmetrical ends, light brown to brown, smooth-walled. Asexual morph : hyphomycetous conidia-like structures in culture. Conidiophores and conidiogenous cells absent. Conidia (12–)16–23 µm diam. (n = 30), superficial, globose to subglobose, multiseptate, brown to dark brown, smooth-walled. Culture characteristics:—Conidia germinating on WA within 12 hrs. Colonies growing on malt extract agar (MEA), reaching 18 mm in 2 weeks at 28°C, effuse, dentate and lobate edges, darkly brown. Mycelium superficial and partly immersed, branched, septate, pale brown to brown, smooth-walled, chlamydospores produced in culture and induced with plant tissues within 90 days. Material examined:— THAILAND , Chiang Mai , Jom Thong , elev. 800–1000 msl., N18 o 31’ E 98 o 29’ , on dead branches of an unidentified plant, 16 November 2010 , R . Phookamsak, ITN04: MFLU 11–0002 , holotype ; ex-type living culture, MFLUCC 11–0002 = BBC 52152 . Notes:—Phylogenetic analysis of a combined LSU, ITS and SSU sequence dataset ( Fig. 1 ) indicates that our new taxon Triseptata sexualis (MFLUCC 11–0002) forms a well-resolved single lineage basal to the sister clade of Latoruaceae with 99% MLBS and 1.00 BYPP support.