Fusiformiseptospora thailandica G.C. Ren & K.D. Hyde, sp. nov. Fig. 2

Facesoffungi Number: FoF 10703

Etymology ‒ Name refects the country from where this species was collected, Thailand.

Holotype ‒ xxx

Saprobic on dead woody twigs of Castanopsis sp. Sexual morph: Ascomata 140–190 × 155–210 μm (x̅ =165 × 180 μm, n = 5), superficial, solitary, scattered, erumpent to immersed, uni-loculate, globose to subglobose, black. Ostiole central. Peridium 20–35 μm wide, thick, comprising of 3–5 layers of light brown to brown cells of textura angularis. Hamathecium of sparse, 1–2 μm wide, cylindrical, septate, branches, cellular pseudoparaphyses. Asci 60–80 × 12–16 μm (x̅ =73.9 × 14.9 μm, n = 20), 8-spored, bitunicate, fissitunicate, clavate, slightly broad at median, apically rounded, with short rounded pedicel. Ascospores 24–26.5 × 5–6 μm (x̅ = 25.5 × 5.3 μm, n = 30), overlapping uni to bi-seriate, pale brown, narrowly fusiform, cell above median septum slightly wider than below, tapering towards the ends, slightly acute at both ends, with 4–5 transversely septa, constricted at the septa, smooth-walled, guttulate, without mucilaginous sheath. Asexual morph: Undetermined.

Culture characteristics ‒ Colonies on PDA, reaching 15–20 mm diam. in 14 days at room temperature (25–30 ℃), superficial, entire margin, umbonate at the center, surface rough, with dense mycelia, velvety, raised, gray at the center, white at edge; reverse atrovirens, darkening towards center and white at the edge.

Known distribution ‒ Castanopsis sp. (Thailand)

Material examined ‒ Thailand, Tak Province, Mogro Amphoe Umphang, on dead woody twigs of Castanopsis sp., 20 August 2019, G.C. Ren, T213 (MFLU xxx holotype), ex-type culture MFLUCC xxx; ibid., T214 (KUN-HKAS 122791, paratype), ex-paratype culture KUMCC 21-0652.

Figure 2Fusiformiseptospora thailandica (MFLU xxx, holotype). a, b Appearance of ascomata on host substrate. c Section of ascoma. d Peridium. e Hamathecium. f Asci. g‒j Ascospores. k Germinated ascospore. l, m Culture characters on PDA (l = from above, m = from below). Scale bars: c = 50 μm, d, e, k = 20 μm, f = 30 μm, g‒j = 10 μm, l, m = 30 mm.