Pseudorhypophila hyalibasiconica Bhagya, Phukhams., K. D. Hyde & E. B. G. Jones 2026, sp. nov.

Pseudorhypophila hyalibasiconica Bhagya, Phukhams., K. D. Hyde & E. B. G. Jones sp. nov. Fig. 6 Etymology. Based on the ascospore morphology. Holotype. MFLU 25-0198. Description. Saprobic on dead and decaying leaf of a Carex sp., appearing as black spherical globes loosely attached to the host tissue. Sexual morph: Ascomata 300–450 μm (x ̄ = 320 μm, n = 5) cleistothecial, gregarious in aggregation, scattered on the host, superficial on host surface, globose, black, smooth-walled, non-ostiolate, covered with hyaline to light brown flexuous ascomatal hairs. Peridium 15–20 μm wide (x ̄ = 18 μm, n = 10), relatively thin, single – layer comprising black to light brown cells of textura angularis and textura intricata. Paraphyses not observed. Asci 90–150 × 20–28 μm (x ̄ = 112 × 24 μm), 8 - spored, unitunicate, highly evanescent, cylindrical to subcylindrical or clavate, long pedicellate with nonamyloid (J-) apices. Ascospores 24–30 × 12–14 μm (x ̄ = 25.5 × 13.5 μm, n = 20), uniseriate or overlapping biseriate, upper cell, 17–22 × 11–14 μm (x ̄ = 19.5 × 12.5 μm, n = 20), fusiform, narrowing towards apex, apiculate, ovoid to limoniform, hyaline when young, greenish-brown to dark brown at maturity, aseptate, smooth-walled; basal cell 5–7 × 4–6 μm (x ̄ = 5.5 × 5.2 μm, n = 10), limoniform when young, conical when at maturity, deliquescing, pedicel-like, hyaline, originating at the base, narrowing to blunt base. Asexual morph: Undetermined. Material examined. Thailand • Prachuap Khiri Khan Province, Pran Buri District, Pranburi River, on decaying leaf of Carex sp. (Cyperaceae), 25 August 2023, Tharindu Bhagya, TB 125 (MFLU 25-0198, holotype); ex-type living culture, MFLUCC 25-0236; ibid., TB 125 B (MFLU 25-0199, isotype). GenBank numbers. MFLU 25-0198: ITS = PV 764279, LSU = PV 764280, rpb 2 = PV 786267, tub 2 = PV 799943; MFLU 25-0199: ITS = PV 764278, LSU = PV 764281, rpb 2 = PV 786268. Notes. Pseudorhypophila hyalibasiconica (MFLUCC 25-0236) clustered with Ps. formosana (NTUPPMCC 22-297) with 100 % ML and 1.00 BYPP statistical support (Fig. 3). The new isolate agrees with the general description of Pseudorhypophila by possessing globose, subglobose ascomata with flexuous ascomatal hairs, unitunicate asci with inconspicuous apical rings and 2 - celled ascospore with olivaceous brown to dark brown, ovoid to limoniform upper cells and hyaline, pale olivaceous smaller lower cell (Fig. 6; Harms et al. 2021). Pseudorhypophila hyalibasiconica (MFLUCC 25-0236) is phylogenetically distinct from Ps. formosana (NTUPPMCC 22-297) with 3.28 % in ITS, 1.01 % in LSU, 7.32 % in tub 2 and 8.19 % for the rpb 2 in base pairs including gaps. Pseudorhypophila mangenotii differs from other species based on the presence of an ostiole to the ascomata, while P. pilifera and P. marina are distinguishable from each other based on the shape of the ascospores basal cell (Harms et al. 2021). Pseudorhypophila hyalibasiconica (MFLUCC 25-0236) is distinguishable from closely related species, Ps. formosana (NTUPPMCC 22-297), and Ps. mangenotii (CBS 419.97) by possessing non-ostiolate, cleistothecial ascomata. It further distinguishes itself from Ps. pilifera (CBS 413.73) by ovoid to limoniform upper cells and conical lower cell at maturity. Pseudorhypophila currently comprises five species, with this study introducing Ps. hyalibasiconica as the sixth species from Thailand (Harms et al. 2021; Cheng et al. 2025).