Niesslia wurfbainiae C.F. Liao, Doilom & K.D. Hyde, in Cao et al., Fungal Diversity 132: 485 (2025)

Index Fungorum number: IF 903222; MycoBank number: MB 903222; Facesoffungi number: FoF 17091; Figs. 1, 2

Etymology – in reference to the host Wurfbainia villosa from which it was isolated.

Holotype – MHZU 24–0032.

Saprobic on dead stems of Wurfbainia villosa. Sexual morph: Ascomata 125–155 µm (av. 142 µm), superficial solitary to aggregated, black, globose, sessile, collapsing cup-like when dry, with a central ostiole, setose. Setae 70–110 × 4–9 µm (av. 95 × 7 µm), acute, with a wide base, simple, dark or gold brown, light twisted, thick-walled. Exciple 10–15 mm wide, dark brown cells of textura angularis epidermoid in transversal section. Paraphyses not observed in mature perithecia. Asci 35–50 × 6–11 µm (av. 45 × 10 µm), cylindric-clavate to clavate, with a short foot at the base and a truncate apex, unitunicate, 4-spored, I–, K/I–. Ascospores 16–22 × 3–5 µm (av. 20.5 × 4 µm), uniseriate or biseriate, elongate ellipsoid to fusiform, tapers from the middle to the sides overlapping, verrucous, without perispore, with round ends, hyaline, 1-septate with 2–3-guttules in each cell. Asexual morph: undetermined.

Culture characteristics – colonies on PDA reaching 15 mm diam. at 25 °C after two weeks, flat, dry, rough, felty, margin undulate and irregular; gray both from above and below; not producing pigmentation in the culture.

Material examined – CHINA, Guangdong Province, Yangchun City, on dead stems of Wurfbainia villosa (Lour.) Škornick. & A.D. Poulsen. (Zingiberaceae), 10 April 2022, C.F. Liao & Y.H. Yang, YAM26 (MHZU 24–0032, holotype; ZHKUCC 24–0225, ex-type) and YAM27.

GenBank – ZHKUCC 24–0225: PQ773318 (ITS), PQ773319 (LSU), PQ778211 (SSU).

Notes – The morphological characteristics of Niesslia wurfbainiae, such as dark brown ascomata with setose and tendency to collapse into a cup-like shape when dry, align well with the generic concept of Niesslia. However, N. wurfbainiae differs from other species in having four ascospores in its asci, whereas most species typically have eight ascospores and N. robusta occasionally has four to eight ascospores. Niesslia wurfbainiae has longer spine (130–200 µm vs. 25–35 µm) as compared to N. robusta (Gams et al. 2019). Phylogenetically, N. wurfbainiae (ZHKUCC 24–0225) form a distinct subclade which is basal to N. fusiformis (CBS 325.77) and N. indica (CBS 313.74) with 81% ML (Fig. 2). The morphological comparison of N. wurfbainiae with those of N. fusiformis (CBS 325.77) and N. indica cannot be conducted as N. fusiformis (CBS 325.77) and N. indica (CBS 313.74) have been reported as asexual morph while N. wurfbainiae is present in its sexual morph. Based on the phylogenetic and morphological evidence, N. wurfbainiae is proposed as a new species. It is unique in having 4-spored, elongate ellipsoidal to fusiform ascospores, verrucous, 1-septate with 2–3-guttules in each cell.

Figure 1 – Niesslia wurfbainiae (MHZU 24–0032, holotype). a, b Appearance of ascostromata on host surface. c Section through ascoma. d Ascoma with spines. e–i Asci. j–l Ascospores. m Germinated ascospore. n Colony on PDA (front and below). Scale bars: c–e = 100 µm, f, g–i = 50 µm, j–l = 10 µm, m = 20 µm.

Figure 2 – Maximum Likelihood consensus tree inferred from the combined ITS, LSU and tef1 multiple sequence alignments. Bootstrap support values for Maximum Likelihood (ML) equal to or greater than 80%. The scale bar indicates expected changes per site. The tree is rooted to Trichoderma aggressivum f. europaeum CBS 100526. Ex-type strains are indicated with “T”. The newly generated sequences are indicated in red.