Plenodomus guttulatus Ariyawansa & K.D. Hyde, sp. nov.
Index Fungorum number: IF551467, Facesoffungi number: FoF 01160.
Etymology: The name refers to the nature of the ascospore wall (containing, or appearing to be sprinkled with drops of oil).
Holotype: MFLU 15-1876
Saprobic on dead stems in terrestrial habitats.Sexual morph: Ascomata 230–325 μmhigh × 260–310 μmdiam ( = 298 × 286 μm, n = 5), solitary, scattered or in small groups, appearing as small, raised black dots on host surface, semi-immersed to immersed, subglobose to depressed globose, broadly or narrowly conical, small- to medium-sized, dark brown to black, smooth,ostiolate. Ostiole with a conical, black, welldeveloped papilla, ostiolar canal filled with periphyses. Peridium 48–88 μm wide at the sides, comprising two layers of scleroplectenchymatous cells, outer layer composed of heavily pigmented, thick-walled cells of textura angularis, inner layer composed of subhyaline or light brown cells of textura angularis, cells near the base comparatively larger. Hamathecium 1–1.5 μm (x̅ = 1.25 μm, n = 10) wide, long, septate, cellular pseudoparaphyses, branching and anastomosing between the asci, embedded in a gelatinous matrix. Asci 70–72 × 5–8 μm ( = 71 × 7 μm, n = 20), 8-spored, bitunicate, fissitunicate, cylindrical, with a bulbous pedicel, rounded at the apex, with an ocular chamber. Ascospores 22–24 × 2–3 μm ( = 23 × 2.8 μm, n = 40), uni-seriate, partially overlapping, yellowish brown, long fusiform, 5-septate, not or slightly constricted at each septum, cell above central septum slightly wider, guttulate only at the central cells, lacking a mucilaginous sheath. Asexual morph: undetermined.
Material examined: GERMANY, Frankfurt, on dead stem, 28 November 2013, H.A. Ariyawansa (MFLU 15-1876, holotype); ibid., (GZAAS, isotype);.
Notes: Single spore isolation was not successful and DNA was extracted directly from the fruiting body. Therefore no living culture is available.
Fig.Plenodomus guttulatus(holotype)a. Appearnce of ascomata on host specimen.b. Close-up of ascomata with ostiole. c, d. Sections of ascomata. e. Cellular pseudoparaphyses f. Section of peridium. g-j. Asci with 8 ascospores.k-m Mature and immature ascospores guttulate only at the central cells. Scale bars: c = 75 μm, d = 50 μm, e = 10 μm, f = 20 μm, g-i = 25 μm, j = 35 μm, k–m = 5 μm.