Pseudomonodictys aquatica D.F. Bao, H.Y. Su, K.D. Hyde & Z.L. Luo, sp. nov. FIGURE. 2

MycoBank number: MB; Index Fungorum number: IF; Facesoffungi number: FoF 11439;

Etymology:—referring to the aquatic habitat of this fungus.

Holotype:—MFLU 22–0079

Saprobic on submerged decaying wood. Sexual morph: Ascomata 228–335 µm high, 212–350 µm diam, solitary, scattered, semi-immersed to erumpent, visible as raised, globose to subglobose, black, ostiolate. Ostiole short papillate, with an irregular pore-like opening, brown to dark brown. Peridium composed of several layers of brown to dark brown cells of textura agularis, merged with the host tissues, outer layers intermixed with host cortex. Hamathecium composed of 2–3 µm wide, dense, filamentous, branched, septate, hyaline, cellular pseudoparaphyses. Asci (120–)130–161(–180) × 20–23 µm (x̅ = 145.8 × 22.8 µm, n = 30), 8-spored, bitunicate, fissitunicate, clavate, short pedicellate, apically rounded, with an ocular chamber. Ascospores 40–48(–52) × 8–10 µm (x̅ = 44.2 × 8.9 µm, n = 35), overlapping, 2–3-seriate, fusiform to cylindrical with round ends, slightly curved, (6–)8-septate, strongly constricted at the septa, narrow towards the both ends, enlarged at the 4th and 5th cells from the apex, smooth-walled, hyaline, with small guttules, surrounded by a distinct, thick, mucilaginous sheath. Asexual morph: Undetermined.

Culture characteristics: Ascospores germinated on PDA within 24 h. Reach 30 mm diam. in 30 days at room temperature, surface rough, with dense mycelia, dry, grey at the margin and center, dark grey to dark brown at the middle from above; grey at the margin and dark brown at middle from below; not producing pigmentation in culture.

Material examined: — Thailand, Chiang Rai Province, on decaying wood submerged in a small stream, 7 March 2021, D.F. Bao, 2CR 17 (MFLU 22–0079, holotype); ex-type living culture, MFLUCC 22–0018. Thailand, Chiang Rai Province, on decaying wood submerged in a small stream, 7 March 2021, D.F. Bao, 2CR 19 (KUN-HKAS 124177, paratype); living culture, MFLUCC 22–0019.

FIGURE 2. Pseudomonodictys aquatica (MFLU 22–0079, holotype). a–c. The appearance of ascomata on host substrate. d. Vertical section of ascoma. e. Ostiole. f, h. Peridium. g. Pseudoparaphyses. i–m. Asci. n-q. Ascospores. r. Germinating ascospore. s, t. Culture on PDA. Scale bars: d–e = 100 µm, f–h = 30 µm, i–m = 50 µm, n–r = 20 µm.