Aquatospora cylindrica W. Dong, H. Zhang & K.D. Hyde, in Dong et al., Fungal Diversity: 10.1007/s13225-020-00463-5, [61] (2020)

MycoBank number: MB 557904; Index Fungorum number: IF 557904; Facesoffungi number: FoF 09246;

Etymology: referring to cylindrical ascospores of this fungus

Holotype: MFLU 18-1534

Saprobic on decaying wood submerged in freshwater. Sexual morph: Ascomata 600–650 μm high, 800–900 μm diam., black, scattered or gregarious, superficial, hemi-sphaerical to conical, base flattened, carbonaceous, with ostiolate papilla. Ostiole central, relatively broad, circular, black. Peridium up to 155 μm at the sides and 65 μm at the base, carbonized, composed of black amorphous layer, whose cells are obscured. Pseudoparaphyses 0.5 μm diam., numerous, trabeculate, filiform, hyaline, sparsely septate. Asci 175–270 × 50–65 μm (x̄  = 225 × 58 μm, n = 10), 8-spored, bitunicate, clavate to narrowly ellipsoidal, straight or slightly curved, with a short pedicel, apically rounded. Ascospores 70–85 × 20–25 μm (x̄ = 77 × 23 μm, n = 10), 2–4-seriate, cylindrical, slightly tapering at two sides, 1-septate, constricted at the septum, hyaline, straight, with four prominent big guttules, thin-walled, smooth, without a sheath. Asexual morph: Undetermined.

Culture characteristics: On PDA, colony circular, reaching 40 mm in 35 days at 25 °C, brown to white from above, dark brown from below, surface rough, dry, raised, edge entirely.

Material examined: THAILAND, Songkhla Province, on submerged wood in a stream, 10 May 2018, W. Dong, hat146-1 (MFLU 18-1534, holotype), ex-type living culture MFLUCC 18-1287; ibid., hat146-2 (HKAS 105042, isotype), ex-type living culture KUMCC 19-0060.

Fig. 28 Aquatospora cylindrica (MFLU 18-1534, holotype). a Appearance of black ascomata on host. b, c Vertical section of ascoma. d Structure of peridium. e Pseudoparaphyses. fh Bituni- cate asci. ik Ascospores. k Ascospore in Indian Ink. l Germinated  ascospore. m, n Colony on PDA (left-front, right-reverse). Scale bars: c = 200 μm, d, f–l = 50 μm, e = 20 μm