Pleomorphic Dematiomelanomma yunnanense gen. et sp. nov. (Ascomycota, Melanommataceae) from grassland vegetation in Yunnan, China Author Gao, Ying https://orcid.org/0000-0001-8671-1978 Center for Mountain Futures, Kunming Institute of Botany, Honghe 654400, Yunnan, China & School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand Author Zhong, Tingfang https://orcid.org/0009-0000-2767-1347 Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand & Key Laboratory of Economic Plants and Biotechnology and the Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China Author Bhat, Jayarama D. https://orcid.org/0000-0002-3800-5910 University of Chinese Academy of Sciences, Beijing 100049, China & Department of Botany and Microbiology, College of Science, King Saud University, P. O. Box 2455, Riyadh- 11451, Saudi Arabia Author Gomes de Farias, Antonio Roberto https://orcid.org/0000-0003-4768-1547 School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand Author Dawoud, Turki M. https://orcid.org/0000-0002-1444-4185 University of Chinese Academy of Sciences, Beijing 100049, China Author Hyde, Kevin D. https://orcid.org/0000-0002-2191-0762 School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand Author Xiong, Weiqiang https://orcid.org/0009-0002-0210-1625 Biology Division, Vishnugupta Vishwavidyapeetam, Ashoke, Gokarna 581326, India Author Li, Yunju https://orcid.org/0000-0001-7165-1984 Science and Technology on Aerospace Chemical Power Laboratory, Hubei Institute of Aerospace Chemotechnology, Xiangyang, 441003, Hubei, China & The State Phosphorus Resource Development and Utilization Engineering Technology Research Centre, Yunnan Phosphate Chemical Group Co. Ltd, Kunming, China Author Gui, Heng https://orcid.org/0000-0002-0946-1589 Center for Mountain Futures, Kunming Institute of Botany, Honghe 654400, Yunnan, China & Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand Author Yang, Xuefei https://orcid.org/0000-0002-0986-2745 Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand & Key Laboratory of Economic Plants and Biotechnology and the Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China Author Wu, Shixi https://orcid.org/0009-0006-5601-733X Biology Division, Vishnugupta Vishwavidyapeetam, Ashoke, Gokarna 581326, India shixi_wu@outlook.com Author Wanasinghe, Dhanushka N. https://orcid.org/0000-0003-1759-3933 YTH Modern Agriculture Development Co. Ltd, Kunming, China & Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand dnadeeshan@gmail.com text MycoKeys 2023 2023-07-25 98 273 297 http://dx.doi.org/10.3897/mycokeys.98.107093 journal article http://dx.doi.org/10.3897/mycokeys.98.107093 1314-4049-98-273 038820BB9AC751329493928106B5ABAA Dematiomelanomma Wanas., Y. Gao, H. Gui & K.D. Hyde gen. nov. Etymology. The generic epithet comes from combining the words Dematio and Melanomma , meaning brown spores in Melanommataceae . Description. Saprobic on dead woody stalks. Sexual morph : Ascomata solitary or gregarious, superficial, black, globose to subglobose, ostiolate. Ostiole central, papillate or apapillate, filled with hyaline cells. Peridium multi-layered, comprising cells of textura angularis. Hamathecium comprising of hyaline, filamentous, branched or unbranched, septate pseudoparaphyses. Asci eight-spored, bitunicate, fissitunicate, cylindrical to cylindric-clavate, with a pedicel, rounded and thick-walled at apex, with an ocular chamber. Ascospores uniseriate, sometimes overlapping, muriform, ellipsoidal to fusiform, narrowly rounded at ends, initially hyaline, becoming brown at maturity, with transverse septum appearing first, later becoming vertically septate, smooth-walled, with a mucilaginous sheath. Asexual morph : Synanamorphic. Conidiomata pycnidial, solitary or gregarious, mostly superficial, obpyriform, dark brown to black, ostiolate. Ostiole single, circular, centrally papillate with periphyses. Conidiomatal wall multi-layered, thick-walled, dark brown, composed of cells of textura angularis, inner layer with hyaline cells. Macroconidiogenous cells enteroblastic, annellidic, integrated, indeterminate, doliiform, smooth-walled, hyaline, arising from the innermost layer of pycnidial wall. Macroconidia medium brown to dark brown, ellipsoidal to fusiform, phragmosporous to muriform, curved to straight. Microconidiogenous cells present or absent in cultures; when present, hyaline, integrated, enteroblastic, percurrently annellidic, ampulliform to subcylindrical. Microconidia present or absent; when present, hyaline, round to oblong or ellipsoidal, with small guttules. Type species. Dematiomelanomma yunnanense Y. Gao, Wanas., H. Gui & K.D. Hyde.