Morphological and phylogenetic appraisal of a new Kirschsteiniothelia (Dothideomycetes, Kirschsteiniotheliales) species from Yunnan Province, China Author Meng, Qing-Feng 0000-0001-9814-8238 School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand & Centre of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand & School of Public Health, Zunyi Medical University, Guizhou Province 563000, China qfmeng@126.com Author Thiyagaraja, Vinodhini 0000-0002-8091-4579 Centre of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand & Key Laboratory for Plant Biodiversity and Biogeography of East Asia (KLPB), Kunming Institute of Botany, Chinese Academy of Science, Kunming 650201, Yunnan, China & Yunnan Key Laboratory for Fungal Diversity and Green Development, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China vino.thiyagaraja@gmail.com Author Worthy, Fiona Ruth 0000-0003-0042-3110 Key Laboratory for Plant Biodiversity and Biogeography of East Asia (KLPB), Kunming Institute of Botany, Chinese Academy of Science, Kunming 650201, Yunnan, China & Yunnan Key Laboratory for Fungal Diversity and Green Development, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China worthy@mail.kib.ac.cn Author Ertz, Damien 0000-0001-8746-3187 Meise Botanic Garden, Research Department, Nieuwelaan 38, 1860 Meise, Belgium & Fédération Wallonie-Bruxelles, Service Général de l’Enseignement Supérieur et de la Recherche Scientifique, rue A. Lavallée 1, 1080 Bruxelles, Belgium damien.ertz@jardinbotaniquemeise.be Author Wang, Xin-Yu 0000-0003-2166-6111 Key Laboratory for Plant Biodiversity and Biogeography of East Asia (KLPB), Kunming Institute of Botany, Chinese Academy of Science, Kunming 650201, Yunnan, China & Yunnan Key Laboratory for Fungal Diversity and Green Development, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China wangxinyu@mail.kib.ac.cn Author Jayawardena, Ruvishika S. 0000-0001-7702-4885 School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand & Centre of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand ruvi.jaya@yahoo.com Author Fu, Shao-Bin 0000-0001-9932-1346 School of Pharmacy, Zunyi Medical University, Guizhou Province 563000, China fushb@126.com Author Saichana, Natsaran 0000-0002-4357-7980 School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand natsaran.sai@mfu.ac.th text Phytotaxa 2024 2024-08-01 661 3 267 281 https://doi.org/10.11646/phytotaxa.661.3.4 journal article 10.11646/phytotaxa.661.3.4 1179-3163 14516754 Kirschsteiniothelia laojunensis Q.F. Meng & S.B. Fu sp. nov. Index Fungorum number: IF901188; Facesoffungi number: FoF15351; Fig. 2 Etymology : The specific epithet “ laojunensis ” refers to the geographic name of Laojun Mountain, where the holotype was collected. Saprobic on the bark of Abies fabri ( Pinaceae ). Sexual morph: Ascomata perithecial, superficial, erumpent, the base surrounded by the lichen thallus tissue of Ochrolechia sp. , irregularly scattered, rarely clustered, sessile, subglobose to globose, black, with a smooth surface, 1–1.5 mm in diameter, and possessing an apex ostiolate. Peridium 50–80 μm thick on both sides, the upper part 65–100 μm thick, dark brownish to black, composed of highly melanised irregular cells. Pseudoparaphyses 1.5–2.5 μm thick, branched. Asci (105–) 130–162 (–180) × (17–) 20–30 μm ( x = 150 × 26 μm, n = 6), 8-spored, bitunicate, clavate, K-. Ascospores (34–) 35–55 (–56) × (10–) 11–14 (–16) μm ( x = 48 × 13 μm, n = 30), length to width ratio (l/w) = 3.3–3.9 ( x = 3.8, n = 30), usually 2-celled with a septum, slightly constricted at the septum, hyaline when young and turning dark brown with greenish or bluish coloration at maturity, fusiform, asymmetric with a slightly larger upper cell, both ends slightly subacute, guttulate, with two central globose guttules either side of the septum, smaller guttules elsewhere. Asexual morph: Not observed. Material examined : China , Yunnan Province , Lijiang City, Laojun Mountain National Nature Reserve, 26°37′54.86″N , 99°43′28.13″E , elev. 4000 m , on the bark of Abies fabri ( Pinaceae ), 9 th August 2022 , collected by Qing-Feng Meng, Coll. No. ljs-29 (KUN-L 88727, holotype ). Notes : The phylogenetic analysis of combined LSU and ITS sequence data reveals that Kirschsteiniothelia laojunensis forms a sister clade with K. thujina (JF 13210). However, nucleotide comparison differences between Kirschsteiniothelia laojunensis and K. thujina (JF13210), showed a difference of 1.57% (12/765 bp) for LSU and 5.27% (27/512 bp) for ITS. The new taxon differs from Kirschsteiniothelia thujina in having wider diameter ascomata (1000–1500 μm vs. 350–500 μm), longer asci (130–162 × 20–30 μm vs. 100–140 × 17–22 μm) and narrower ascospores (35–55 × 11–14 μm vs. 36–50 × 15–17 μm) ( Hawksworth 1985 ).