Halobyssothecium cangshanense (Z.L. Luo, X.J. Su & K.D. Hyde) M.S. Calabon, K.D. Hyde & E.B.G. Jones, Mycol. Progr. 20: 715 (2021).

Index Fungorum number: IF 558092; MycoBank number: MB 558092; Facesoffungi number: FoF 09434; Fig. 1

Saprobic on decaying bamboo in freshwater habitats. Sexual morph: Ascomata 170–270 µm high, 150–250 µm in diam., scattered or clustered, semiimmersed to partially erumpent, conical or subglobose, black, papillate in the center, ostiolate. Peridium 20–30 µm wide, composed of several layers of pseudoparenchymatous cells, arranged in a textura angularis, hyaline to subhyaline at the inner part, pigmented at the outer part. Pseudoparaphyses 2.5 − 3.5 μm wide, numerous, septate, embedded in a mucilaginous matrix. Asci 65–114 × 9–12 µm (x̅=87.8 × 10.8 μm, n=15), 8-spored, bitunicate, clavate, pedicellate, with a rounded apex and an ocular chamber. Ascospores 15.5–19.5 × 3.5–5.5 µm (x̅=17.6 × 4.5 μm, n=20), 1–2-seriate, broadly fusiform, straight or slightly curved, yellowish brown, 1-septate in the central, slightly constricted at the septum, upper cell wider, guttulate when young, smooth-walled. Asexual morph: Undetermined.

Culture characteristics – On PDA, colony circular on the whole, germinating within 24 h, reaching 40 mm in 1 month at room temperature (25 °C), dark brown from above and below, surface rough and dry, umbonate, with dense brown mycelium in the middle, sparse mycelium in the regular edge.

Material examined – China, Sichuan Province, Yibin, Changning river, on submerged bamboo, 29 March 2021, Y. Qing, CN16 (IFRD, new record for China).

GenBank numbers – LSU=KU991149, SSU=KU991150.

Notes – Halobyssothecium cangshanense was originally introduced as Lentithecium cangshanense by Su et al. (2016) from Yunnan Province, China, and subsequently transferred to Halobyssothecium by Calabon et al. (2021) based on phylogenetic analysis. Phylogenetically, our isolate clusters with H. cangshanense with strong support. Morphologically, our isolate fits the characters of H. cangshanense except for the slightly narrower conidia (3.5–5.5 µm vs. 6–7 μm). This is the first time to report it from Sichuan Province, China.

Figure 1 – Halobyssothecium cangshanense. a, b Colonies on substrate. c, d Asci. e–l Ascospores. m Germinating ascospore on PDA. n Surface view of culture on PDA. o Reverse view of culture on PDA. Scale bar: c, d=15 µm, e–l=10 µm, m=25 µm