Helminthosporiella stilbacea

Helminthosporiella stilbacea

Konta & K.D. Hyde (2021)

Classification:Ascomycota-Pezizomycotina-Dothideomycetes-Pleosporomycetidae-Pleosporales-Massarinaceae-Helminthosporiella

Host species: Cocos nucifera (Konta et al. 2021)

Holotype: MFLU 20-0521 (Konta et al. 2021)

Known distribution: Prachuap Khiri Khan, Thailand

IF Number: IF558312     Mycobank Number: 558312     FOF Number: FoF09172

Description

Saprobic on dead petiole of Cocos nucifera. Sexual morph: Undetermined. Asexual morph: Colony on natural substrate black, hairy. Mycelium mostly immersed, at the surface forming small stroma-like aggregations of dark brown pseudoparenchymatous cells (6–)11–15(–25) μm diam (x̄ = 14 μm). Conidiophores (60–)165–270(–310) × (5–)7–9(–12) μm (x̄ = 200 × 8 μm, n = 30), macronematous, wide at the apex and base, arising singly from the stroma cells, erect, simple, unbranched, straight or flexuous, thick-walled, cylindrical, smooth-walled, dark brown, becoming pale brown at the apex, (4–)12–15-septate. Conidiogenous cells terminal and intercalary, polytretic, with well-defined thick, pale brown pores. Conidia (30–)45–60(–70) × 6–9 μm (x̄ = 50 × 7 μm, n = 30), obpyriform to lageniform, straight or curved, smooth-walled, subhyaline to light brown, 5–8-distoseptate, with a thick scar at the base.

Culture conditions: Culture on MEA, colony yellow-green at the center, turn-ing dull green, pale yellow next, becoming dull green again, pale yellow, and white toward the margin. Colony smooth, dense at the middle, zonate, fluffy at the margin.