Pleosporales » Morosphaeriaceae » Neohelicascus

Neohelicascus uniseptatus

Neohelicascus uniseptatus (J. Yang, J.K. Liu & K.D. Hyde) W. Dong, K.D. Hyde & H. Zhang

Index Fungorum number: IF557929; Facesoffungi number: FoF09271

Basionym: Helicascus uniseptatus J. Yang, J.K. Liu &K.D. Hyde, Phytotaxa 270(3): 187 (2016)


Saprobic on decaying, submerged twigs in aquatic habitats, visible as masses of brown ascospores on the host surface. Sexual morph: Ascostromata 100–200 μm diam, 300–500 μm high, solitary or aggregated in small groups, black, immersed, subglobose or obovate, appearing as slightly raised regions with black ostioles, with periphyses, papillate, black. Peridium 40–48 μm, comprising three fused layers, outer layer darker, with thick-walled cells of textura globosa, middle layer pale brown with thin-walled cells of textura angularis, and inner layer hyaline with flattened, thin-walled cells. Hamathecium composed of septate, hypha-like pseudoparaphyses, 2.2–4.2 μm wide, constricted at the septa, ramified above asci with free ends, embedded in a gel matrix. Asci 130–240 × 16–26 μm ( = 165 × 22 μm, n = 25), 8-spored, bitunicate, fissitunicate, clavate, long pedicellate, base of endoascus long, narrow and coiled within ectoascus, ectoascus uncoiling to form a long tail-like extension, apically rounded with a cylindrical ocular chamber. Ascospores 25–32 × 9–13 μm ( = 27 × 10 μm, n = 35), ellipsoid-fusiform, 2-seriate, uniseptate, constricted at the septum, apical cell usually longer than basal cell, hyaline when young, becoming brown when mature, guttulate, smooth-walled, lacking a mucilaginous sheath. Asexual morph: Undetermined. (Descriptions from Luo et al. 2016)


Material examined: THAILAND, Chiang rai Province, stream flowing near ThamLuang Nang Non Cave, on submerged wood, 25 November 2014, Yang Jing, YJ-4 (MFLU 15–1170, holotype); ex-type living culture, MFLUCC 15–0057.


Notes: Neohelicascus uniseptatus was collected from decaying wood submerged in a freshwater stream in Chiang rai Province, Thailand. Neohelicascus uniseptatus is similar to N. unilocularis by its unilocular ascostromata and ascospores with a smooth wall and lacking a mucilaginous sheath. However, N. uniseptatus differs from N. unilocularis in having smaller ascostromata (100–200 versus 200–220 μm), a thinner peridium (40–48 versus 50–65μm), and longer ascospores (25–32 versus 23–25.8 μm). In addition, N. uniseptatus is phylogenetically close to N. aegyptiacus in the phylogenetic analysis (Dong et al. 2020)


Freshwater distribution: Thailand (Luo et al. 2016)


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Fig 1. Helicascus uniseptatus (MFLU 15–1170, holotype) a. Specimen; b. Appearance of masses of ascospores on surface of host; c. Mass of spores on host surface; d. Section of ascoma; e. Section of peridium; f. Paraphyses; g–l. Asci; m–q. Ascospores; r. Germinating ascospore; s, t. Culture grow on PDA after 4 weeks, s. upper side, t. reverse side. Scale bars: b = 1000 μm; c = 200 μm; d = 100 μm; e, f.

(Retrieved from



Dong W, Wang B, Hyde KD, McKenzie EHC, Raja HA, Tanaka K, Abdel-Wahab MA, Abdel-Aziz FA, Doilom M, Phookamsak R, Hongsanan S, Wanasinghe DN, Yu XD, Wang GN, Yang H, Yang J, Thambugala KM, Tian Q, Luo ZL, Yang JB, Miller AN, Fournier J, Boonmee S, Hu DM, Nalumpang S, Zhang H (2020) Freshwater Dothideomycetes. Fungal Divers 105:319–575.

Luo ZL, Yang J, Liu JK, Su HY, Bahkali AH, Hyde KD (2016) Two new species of Helicascus (Morosphaeriaceae) from submerged wood in northern Thailand. Phytotaxa 270:182–190



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