Obliquiminima hyalina W. Dong, H. Zhang & K.D. Hyde, sp. nov.    Fig. 9

MycoBank number: MB 558036; Index Fungorum number: IF 558036; Facesoffungi number: FoF 09557;

Etymology – in reference to hyaline ascospores of the fungus

 Holotype – MFLU 18-1521

Saprobic on submerged wood in freshwater. Sexual morph: Ascomata 130–150 μm high, 140–160 μm diam., scattered, superficial, ellipsoidal to subglobose, black, coriaceous, ostiolate, with a lateral neck. Necks short, black, cylindrical, oblique to the substrate surface. Peridium 10–15 μm thick, comprising 5–7 layers of dark brown to black, thick-walled, compressed cells of textura angularis. Paraphyses up to 15 μm diam. at the base, tapering towards the apex, dense, hypha-like, septate, constricted at septa, unbranched, hyaline. Asci 150–215 × 16–20.5 μm ( x = 178 × 18.5 μm, n = 20), 8-spored, unitunicate, narrowly obclavate, slightly truncate at apex, sessile, with a small, refractive, discoid, apical ring, 2.4 × 4.2 μm. Ascospores 30.5–37.5 × 9–12.5 μm ( x = 34.5 × 10.5 μm, n = 10), uni- to bi-seriate, oval, narrowly ellipsoidal, straight, aseptate, 3-septate when germinated, finely guttulate, hyaline, thin-walled, smooth, with a thin gelatinous sheath. Asexual morph: Undetermined.

Culture characteristics – On PDA, colony circular, reaching 20 mm in 47 days at 25°C, gray brown from above, dark brown from below, surface rough, dry, with dense mycelium, raised, entire at edge.

Material examined – Thailand, Songkhla Province, on submerged wood in a stream, 10 May 2018, W. Dong, hat142 (MFLU 18-1521, holotype), ex-type living culture MFLUCC 18-1235; ibid., HKAS 105009, isotype, ex-isotype living culture KUMCC 19-0025; chestnut hill, on submerged wood in a stream, 10 May 2018, W. Dong, hat459 (MFLU 18-1529), living culture MFLUCC 18-1401; ibid., HKAS 105046, living culture KUMCC 19-0065.

Figure 9 – Obliquiminima hyalina (MFLU 18-1521, holotype). a Ascomata on host substrate. b Vertical section of ascoma. c Structure of peridium. d–g Unitunicate asci. h, i Ascospores in water. j, k Ascospores in Indian Ink. l, m Apical rings. n Germinated ascospores. o, p Colony on PDA (left-front, right-reverse). Scale bars: b = 50 μm, c, e, f, h–k = 20 μm, d, g, n = 30 μm, l, m = 10 μm.