Neohelicascus chiangraiensis

Neohelicascus chiangraiensis (Z.L. Luo, J.K Liu, H.Y. Su & K.D. Hyde) W. Dong, K.D. Hyde & H. Zhang

Index Fungorum number: IF557923; Facesoffungi number: FoF09265

Basionym: Helicascus chiangraiensis Z.L. Luo, H.Y. Su & K.D. Hyde, Phytotaxa 270(3): 185 (2016)

Saprobic on decaying, submerged wood in freshwater. Sexual morph: Ascostromata 240–270 μm diam, 340–550 μm high, solitary, scattered, black, immersed, unilocular, globose to subglobose, ostiole central. Peridium 30–50 μm, subhyaline to dark brown, composed of several layers of pseudoparenchymatous cells, outer layer dark brown, with thick-walled cells, arranged in a textura angularis, inner layer hyaline with flattened, thin-walled cells. Hamathecium composed of septate, hypha-like pseudoparaphyses, 1.5–2.5 μm wide, slightly constricted at the septa, ramified above asci with free ends, embedded in a gel matrix. Asci 77–146 × 16–19 μm (x̄ = 111.5 × 17.5 μm, n = 20), 8-spored, bitunicate, fissitunicate, clavate, apically rounded, dehiscence, endoascus narrow, coiled within ectoascus, ectoascus forming a long tail extension. Ascospores 24.5–27.5 × 8.5–10.5 μm (x̄ = 26 × 9.5 μm, n = 20), obliquely uniseriate and partially overlapping, ellipsoid-fusiform, verruculose, upper end narrowly rounded, lower end tapering, slightly curved in side view, with 2–4 large refractive guttules, 1-euseptate, septum submedian, hyaline when young, becoming brown when mature, thick-walled, verruculose, slightly constricted at the septum, surrounded by sheath. Asexual morph: Undetermined. (Description from Luo et al. 2016)

Material examined: THAILAND. Chiang Rai Province, saprobic on decaying wood submerged in a pond, October 2013, Asanka Bandara, ZL-11 (MFLU 15–0084, holotype); ex-type living culture, MFLUCC 13-0883, DLUCC; (HKAS 86459, isotype).

Notes: Neohelicascus chiangraiensis is similar to N. aegyptiacus by its coiled endoascus, verruculose ascospores surrounded by a gelatinous sheath and both are collected from freshwater habitats. However, N. chiangraiensis differs from N. aegyptiacus in having unilocular, smaller ascostromata, while N. aegyptiacus has a longer ascostromata, pseudostromata with 2–3(4) dark locules.  Neohelicascus chiangraiensis shared the same clade with N. gallicus based on the phylogenetic analysis of combined LSU, SSU, ITS and TEF sequence data revealed by Dong et al. (2020).

Freshwater distribution: Thailand (Luo et al. 2016)