Falciformispora uttaraditensis

Falciformispora uttaraditensis Boonmee & Huanraluek

Index Fungorum number: IF 557030; Facesoffungi number: FoF 06508

Etymology: Named after Uttaradit Province, Thailand, where this fungus was collected.

Holotype: MFLU 19-2361

Saprobic on the surface of submerged twigs in tidal creeks. Sexual morph: Ascomata 148–268 μm high × 110–224 μm diam. (x̄ = 208 × 179 μm, n = 5), immersed to erumpent, solitary, scattered on substrate, subglobose to globose, coriaceous, dark brown. Peridium 16–44 μm wide, 5 layers of dark brown cells of textura angularis, almost black at outside. Hamathecium with 2 μm wide, anastomosing, septate, branched pseudoparaphyses, hyaline. Asci 54–108 × 13–27 μm (x̄ = 73 × 18 μm, n = 4), 8-spored, bitunicate, cylindrical-clavate to broadly obpyriform, straight or slightly curved, sessile. Ascospores 28–59 × 6–14 μm (x̄ = 41 × 20 μm, n = 20), 2–3-seriate, fusiform to clavate, slightly curved, tapering towards narrow ends, 6-septate, obviously multi-guttulate when immature, hyaline, surrounded by a distinct mucilaginous sheath. Asexual morph: Undetermined. (Descriptions from Hyde et al. 2020)

Culture characteristics: Ascospores germinating on MEA within 24 h at room temperature and germ tubes produced from the ends of the ascospore. Colonies on PDA reaching 2 cm diam. for one month at 25 °C. Initially aerial mycelium white, slightly raised, becoming grey to dark grey when old, convex with papillate on surface, crenated, green to dark brown from below, white to light yellow margin. (Descriptions from Hyde et al. 2020)

Material examined: THAILAND, Uttaradit Province, Phichai District, Thasak, Ban Cham Tok, on submerged twigs in tidal creeks, 29 December 2018, S. Boonmee, CTU6 (MFLU 19-2361, holotype), ex-type living culture, MFLUCC 19-0485.

Notes: Falciformispora uttaraditensis resembles F. aquatica D.F. Bao, K.D. Hyde & H.Y. Su in having immersed, coriaceous ascomata in wood tissue, dark pigmented, ostiolate, cylindro-clavate to broadly obpyriform asci, and fusiform to clavate, multi-septate, hyaline ascospores, surrounded by a distinct mucilaginous sheath (Hyde et al. 2019). However, F. uttaraditensis differs from F. aquatica in having smaller ascomata, asci and ascospores. Furthermore, phylogenetic analyses indicate that F. uttaraditensis forms a basal lineage in the clade with high statistic support (92%ML, 0.99 BYPP). To justify our new species, we follow the guidelines of Jeewon and Hyde (2016). Comparison of 546 nucleotides of the ITS sequences between F. uttaraditensis (MFLUCC 19-0485) and F. aquatica (MFLUCC 18-0212) reveals 20 nucleotide differences (3.8%), which is sufficient to delineate our new species. (Notes from Hyde et al. 2020)

Freshwater distribution: Thailand (Hyde et al. 2020)