Pseudokeissleriella bambusicola Yi Yang, S.N. Zhang and Jian K. Liu, sp. nov. Figure 2

MycoBank number: MB 888118; Index Fungorum number: IF 888118; Facesoffungi number: FoF 12708;

Etymology: The suffix “-cola” means “inhabitant”, and the epithet “bambusicola” refers to the subfamily of plant host “Bambusoideae”, from which the fungus was collected.

Holotype: HKAS 124020

Saprobic on dead culms of bamboo in a terrestrial habitat. Sexual morph: Ascomata 310–660 µm high, 400–520 µm diam ( = 480 × 450 µm, n = 10), scattered, immersed to slightly erumpent, visible as dark brown to black, circular or lenticular areas with a central black dot, glabrous, in vertical section subglobose, base flattened, unilocular, coriaceous, with a central ostiole. Ostiole 85–160 µm long, 40–85 µm diam. ( = 105 × 55 µm, n = 10), dark brown, periphysate. Peridium 15–45 µm diam, relatively thick, multi-layers, comprising hyaline to brown cells of textura angularis. Hamathecium 1.4–2.3 µm wide, comprising numerous, filiform, branched, septate, pseudoparaphyses. Asci 70–120 × 9–13 µm ( = 95.1 × 11.1 µm, n = 30), 8-spored, bitunicate, fissitunicate, cylindrical to cylindric-clavate, with a short pedicel, apically rounded with an ocular chamber. Ascospores 21–28.5 × 4.2–6.5 µm ( = 25.5 × 5.5 µm, n = 30), overlapping bi-seriate, usually uniseriate in the lower half, fusiform, tapering to subobtuse ends, hyaline, 1(–3)-septate, the upper cell swollen towards the median septum, straight or slightly curved, smooth-walled, guttulate, surrounded by a mucilaginous sheath with depression in the middle. Asexual morph: Undetermined.

Culture characteristics: Spores germinated on PDA within 24h. Colonies growing on PDA, reaching a diameter of 25 mm after 24 d at 25 °C, circular, surface slightly rough, white to faint yellow, reverse yellowish.

Material Examined: China, Sichuan province, Dujiang weir, Qingcheng Mountain, 30°55’7″ N, 103°29’39” E on dead culms of Bamboo, 2 December 2021, Yi Yang, Q6-2 (HKAS 124020, holotype); ex-holotype living culture CGMCC 3.20950; ibid., Xian-Dong Yu, HUEST 22.0030, paratype; ex-paratype living culture UESTCC 22.0028.

Figure 2. Pseudokeissleriella bambusicola. (HKAS 124020, holotype) a–c Ascomata on host surface. d Vertical section of ascomata. e Ostiole. f Peridium. g Hamathecium. h–l Asci, m–t Ascospores. u Ascospore stained with India ink showing the mucilaginous sheath. v Germinating ascospore. w, x Colony on PDA (four weeks). Scale bars: d = 100 μm, e = 50 μm, f–l = 20 μm, m–v = 10 μm.