Pleosporales » Occultibambusaceae » Seriascoma

Seriascoma didymosporum

Seriascoma didymosporum Phook., D.Q. Dai, Karun. & K.D. Hyde [as ‘didymospora’], Fungal Diversity 82: 32 (2016)

Index Fungorum number: IF552015; Facesoffungi number: FoF 01979


Saprobic on submerged wood. Sexual morph: Ascomata 120–170 μm high, 200–250 μm diam., gregarious, immersed to erumpent in linear rows, raised, coriaceous, uniloculate, ostiolate. Peridium 30–50 μm wide, unequal in thickness, composed of several layers of large, dark brown pseudoparenchymatous cells of textura angularis. Pseudoparaphyses 2.5–4 μm wide, numerous, cellular, hypha-like, broadly filamentous, hyaline, septate. Asci 70–95 × 9–11 μm ( = 83 × 9.5 μm, n = 10), 8-spored, bitunicate, fissitunicate, clavate, long pedicellate, apically rounded, with an ocular chamber. Ascospores 10.5–14.5 × 3.5–5 μm ( = 12.5 × 4 μm, n = 20), uni- to tri-seriate, clavate to fusiform, with rounded ends, 1-septate, constricted at the septum, asymmetrical, upper cell shorter and wider than lower cell, hyaline, straight or curved, smooth-walled. Asexual morph: Undetermined.


Culture characteristics: On PDA, colony circular, reaching 10 mm in 15 days at 25 °C, white to pale brown from above, black from below, surface rough, with dense mycelium, dry, raised, edge entire.


Material examined: CHINA, Yunnan Province, Dehong, on submerged wood in a stream, 25 November 2017, G.N. Wang, H158C-1 (MFLU 18-1185), living culture MFLUCC 18-1026; ibid., H158C-2 (HKAS 101720), living culture KUMCC 18-0070.


Notes: The new collection of Dong et al. (2020), MFLUCC 18-1026, clusters with Seriascoma didymosporum with high bootstrap support. MFLUCC 18-1026 is identified as S. didymosporum based on sequence data which has one, four (includes two gaps) and three nucleotide differences in LSU, ITS and TEF sequence data, respectively, between MFLUCC 18-1026 and MFLUCC 11-0179 (ex-holotype). Uniloculate ascomata was observed in the collection of Dong et al. (2020), while the holotype MFLU 11–0215 has multi-loculate ascomata (Dai et al. 2017). In addition, MFLUCC 18-1026 has longer asci [70–95 × 9–11 μm vs. (56–)60–75(−80) × 8–11(−13) μm] than the holotype (Dai et al. 2017, Dong et al. 2020).


Freshwater distribution: China (Dong et al. 2020)