Pleosporales » Morosphaeriaceae » Neohelicascus

Neohelicascus elaterascus

Neohelicascus elaterascus (Shearer) W. Dong, K.D. Hyde & H. Zhang

Index Fungorum number: IF557925; Facesoffungi number: FoF09267

Basionym: Kirschsteiniothelia elaterascus Shearer, Mycologia 85:963 (1993).

Synonymy: Morosphaeria elaterascus (Shearer) S. Boonmee & K.D. Hyde, Mycologia 103: 705 (2012), Helicascus elaterascus (Shearer) H. Zhang & K.D. Hyde, Sydowia 65: 158 (2013)


Saprobic on decaying wood submerged in freshwater. Sexual morph: Pseudostromata 205–250 μm high, 170–200 μm diam., clustered, immersed, unilocular, mammiform, coriaceous, with ostiolate papilla, visible on the host surface as blackened ostiolar dots. Peridium 20–30 μm thick, comprising several layers of brown, thin-walled, pseudoparenchymatous cells, outer layer partially occluded with the host cells, deeply pigmented, inwardly hyaline, forming a textura angularis in the upper regions and a textura prismatica at sides and angles of base. Pseudoparaphyses 1–3 μm diam., abundant, cellular, cylindrical, hyaline, sparsely septate. Asci 95–130 × 17–24 μm ( = 112 × 21 μm, n = 15), 8-spored, bitunicate, fissitunicate, clavate, endoascus separating from ectoascus at time of ectoascus dehiscence, base of endoascus long, narrow and coiled within ectoascus, up to 210 μm long. Ascospores 23–28 × 8–11 μm ( = 25 × 9 μm, n = 25), overlapping uni- or bi-seriate, sometimes overlapping tri-seriate, ellipsoidal, brown, 1-septate, constricted at septum, asymmetrical, apical cell slightly longer than basal cell, curved, thin-walled, smooth in optical microscope, surrounded by a gelatinous sheath. Asexual morph: Undetermined. (Dong et al. 2020)


Culture characteristics: On PDA, colony circular, reaching 40 mm in 45 days at 25 °C, dark brown to black from above, black from below, surface rough, dry, raised, edge undulate.


Material examined: THAILAND, Phayao Province, on submerged wood in a stream, 23 February 2018, X.D. Yu, Y19 (MFLU 18-0997), living culture MFLUCC 18-0985; Chiang Mai Province, Mushroom Research Center, on submerged wood in a stream, 2 April 2018, X.D. Yu, Y29 (MFLU 18-1007), living culture MFLUCC 18-0993.


Notes: Our new collections MFLUCC 18-0985 and MFLUCC 18-0993 are identified as Neohelicascus elaterascus based on morphological and molecular evidence. Shearer (1993b) described verrucose ascospores from the holotype (C-76-1), while our collections have smooth ascospores which are also described by Hyde et al. (2020a). Neohelicascus elaterascus is commonly reported on submerged wood from many countries as listed above. (Notes from Dong et al. 2020)


Freshwater distribution: Brunei (Ho et al. 2001), Chile (Shearer 1993), China (Tsui et al. 2000; Luo et al. 2004), Japan (Tanaka et al. 2015), Peru (Shearer et al. 2015), South Africa (Hyde et al. 1998), Thailand (Dong et al. 2020; Hyde et al. 2020), USA (Shearer 1993; Raja et al. 2009)