Neobyssosphaeria clematidis Wanas., Phukhams., E.B.G. Jones & K.D. Hyde, sp. nov.
MycoBank number: MB 557190; Index Fungorum number: IF 557190; Facesoffungi number: FoF 07282, Fig. 36.
Etymology: Named after the host genus, Clematis. Holotype: MFLU 17–0614.
Saprobic on dead stems of Clematis vitalba. Sexual morph : Ascomata 525–550 × 500–520 μm (x̄ = 535 × 510 μm, n = 5), immersed, ostiole part orange, solitary or gregarious, globose to depressd-globose, coriaceous, indistinguishable from host tissue, brown to pale brown, rough-walled, ostiolate. Ostioles 235–270 × 190–230 μm ( x̄ = 250 × 200 μm, n = 5), central, papillate, opening by a pore, filled with periphyses, with orange pigment around pore. Peridium 30–50(–70 μm at apex) wide, thick, multi- layered, outer layer composed of heavily pigmented, red- dish brown cells of textura angularis, inner layer composed of thin and hyaline cells of textura angularis. Hamathecium composed of numerous, 1.6–3 μm ( x̄ = 2.3 μm, n = 50), dense, filiform, branched, anastomosing, septate, cellular pseudoparaphyses. Asci 160–210 × 20–30 μm ( x̄ = 185 × 25 μm, n = 20), 8-spored, bitunicate, fissitunicate, cylindrical, long pedicellate with a furcated base, clavate, apically rounded, with ocular chamber. Ascospores 55–75 × 8–14 μm ( x̄ = 60 × 11 μm, n = 30), biseriate, partially overlapping, broad fusiform, sometimes inequilateral, with acute ends, hyaline, 7-euseptate, constricted at the septa, cell above median septum enlarged, with guttules in each cell, rough-walled, without mucilaginous sheath. Asexual morph: Undetermined.
Culture characters: Colonies on MEA reaching 20 mm diam. after 4 weeks at 16 °C. Above cream with orange in the middle, with white edge, medium dense, flattened, umbonate, floccose; reverse: cream, thin, flat, circular.
Material examined: UK, Hampshire, Botley wood, on dead stems of Clematis vitalba, 25 May 2016, E.B.G. Jones, GJ 298 (MFLU 17–0614, holotype); ex-type living culture, MFLUCC 17–0794.
Notes: The new fungus morphologically resembles many genera in Pleosporales (e.g. Angustimassarina, Aquastroma, Aquilomyces, Carinispora, Falciformispora, Keissleriella, Lophiopoacea, Lophiostoma, Parabambusicola, Quintaria) in its cylindrical-clavate asci and hyaline, fusiform ascospores with large guttule in each cell (Zhang et al. 2012; Tanaka et al. 2015; Thambugala et al. 2015). However, these taxa are phylogenetically not closely related to Neobyssosphaeria clematidis (see Notes Neobyssosphaeria for further details). Neobyssosphaeria clematidis differs from Byssosphaeria species by its immersed ascomata, lacking hairy hypha protruding from the outside of the peridium (Tian et al. 2015).
Host: Clematis vitalba—(This study).
Distribution: UK—(This study).
Fig. 36 Neobyssosphaeria clematidis (MFLU 17–0614, holotype). a, b Appearance of ascomata on Clematis vitalba. c Vertical section through ascoma. d Close up of ostiolar canal. e Cellular pseudoparaphyses. f, g Asci. h–l Ascospores. Scale bars: a = 1 cm, b = 200 µm, c = 100 µm, d, f–g = 50 µm, e = 5 µm, h–l = 20 µm