Stilbohypoxylon elaeidis

Stilbohypoxylon elaeidis

Konta & K.D. Hyde (2020)

Classification:Ascomycota-Pezizomycotina-Sordariomycetes-Xylariomycetidae-Xylariales-Xylariaceae-Stilbohypoxylon

Host species: Elaeis guineensis (Konta et al. 2020)

Holotype: MFLU 15-0270 (Konta et al. 2020)

Known distribution: Krabi, Thailand

IF Number: IF558007     Mycobank Number: 558007    FOF Number: FoF05123

Description

Saprobic on dead petiole of Elaeis guineensis (Arecaceae). Sexual morph: Stromata superficial, visible as a black conical, or globose on the top view of host surface, solitary, or in groups, bearing conical to acicular synnematal remnants on mature stromata, carbonaceous, brittle, fragile, curved to straight. Ascomata 440–730 × 360–660 μm (x̅ = 565 × 530 µm, n = 25), black, carbonaceous, brittle, conical to mammiform, 1 per stroma, glabrous, covered with remnants of host tissue, disappearing at maturity, with indistinct ostiolate. Synnemata 250–470 μm (x̅ = 340 µm, n = 10), solitary, covered with yellow hyphae-like when immature, spine-like, wide at the base narrow towards the apex, black. Peridium 65–120(–130) µm wide (x̅ = 90 µm, n = 25), thick-walled, composed of several layers, outwardly comprising dark brown to black cells 2–4 µm, of textura angularis. Paraphyses 2.3–3.7 µm wide (x̅ = 3 µm, n = 20), filamentous, cylindrical, septate, unbranched, longer than asci. Asci 113–136 × 7–12 µm (x̅ = 125 × 9 µm, n = 20), 6–8-spored, unitunicate, cylindrical, long pedicellate, apically rounded, with a J+, inverted, hat-shaped apical ring, 2–5 × 2–3 µm (x̅ = 5 × 2 µm, n = 10). Ascospores 13–21 × 5–8 µm (x̅ = 17 × 6 µm, n = 30), uniseriate, hyaline to pale brown when immature, dark brown at maturity, equilateral ellipsoidal to broadly fusoid, unicellular, with two large guttules, smooth-walled, with a straight germ slit over the whole spore length, surrounded by thin mucilaginous sheath, with a pad of denser mucilage at each apex. Asexual morph: Undetermined.

Culture conditions: Ascospores germinated on MEA within 24 hours and germ tube produced from germ slit. Mycelium immersed in media, mycelium at the center appears as grey to dark-green, mycelium towards margin appears white, hyphae, septate, branched, and smooth. Colonies on MEA, medium dense, irregular in shape, flowered-like, surface slightly rough with curled and undulate edge, radiating outward colony, flat, slightly raised at the centre, felty to cotonny, azonate, white at the margin, grey to dark grey near the centre, with black curled radiating towards the centre; reverse yellowish, curled with black radiating towards the centre; not produced pigmentation on medium.