Cyatheomyces synnematosus J. Y. Zhang, Y. Z. Lu & K. D. Hyde, 2025

Cyatheomyces synnematosus J. Y. Zhang, Y. Z. Lu & K. D. Hyde sp. nov.

Figs 2 View Figure 2 , 3 View Figure 3

Etymology.

The species epithet refers to the synnematous conidiomata.

Diagnosis.

Similar to Phaeoisaria and Rhamphoriopsis , but C. synnematosus differs from them by its various conidia.

Holotype.

HKAS 129699 View Materials .

Description.

Sexual morph: Undetermined. Asexual morph: Hyphomycetous. Colonies on natural substrate effuse, scattered or aggregated, brown, with white conidial masses at the apex. Mycelium partly immersed, partly superficial, composed of branched, thick-walled, septate, hyaline to pale brown hyphae. Synnemata up to 78 μm wide near the base, dark brown to hyaline towards the apex, with upper parts of conidiophores slightly splaying out as a flared head. Conidiophores macronematous, synnematous, erect, cylindrical, often flexuous at the conidiogenous region, thick-walled, aseptate, brown to hyaline towards the apex, 158–362 μm × 1.3–2.5 μm ( x ̄ = 281 × 1.8, n = 20). Two modes of development during conidiogenesis; Conidiogenous cells type 1 (Figs 2 F – M View Figure 2 , 3 F View Figure 3 ) monoblastic, integrated, terminal, hyaline or subhyaline, 1.3–2.5 μm wide; Conidiogenous cells type 2 (Figs 2 N View Figure 2 , 3 D – F View Figure 3 ) polyblastic, integrated, terminal, sympodia, with inconspicuous denticles, hyaline or subhyaline, 1.5–2.8 μm wide near the conidiogenous loci. Conidia various, oblong to obovoid to clavate, aseptate when young, 1 (– 2) - septate when mature, sometime indistinct, not constricted at the septum, guttulate, hyaline, rarely pale brown, 11–15 × (2.5 –) 3.7–5 µm ( x ̄ = 13 × 4.4 µm, n = 25).

Culture characteristics.

Conidia germinating on WA within 15 h and germ tube produced from conidia. Colonies growing on PDA, grown slowly, reaching 11–13 mm diameter after one month at room temperature (ca. 26 ° C), circular with entire margin, flat with a protuberance in the center, veined, from which several indentations extend outwards, and cut into fan shapes at the surface, white form above; brown form below, and not producing pigmentation in cultures.

Material examined.

CHINA • Guizhou Province, Zunyi City, Chishui County, Hushi Town, Chishui Alsophila Natural Reserve , on dead frond stalks of Cyathea sp. ( Cyatheaceae ), 27 July 2022, J. Y. Zhang, CX 4 ( HKAS 129699 , holotype; GZAAS 23-0669 , isotype), ex-type living culture, KUNCC 23-13865 ; • ibid., 22 September 2019, J. Y. Zhang, C 4 ( HKAS 129695 = GZAAS 23-0776 , paratype), living culture, GZCC 23-0670 ; • ibid., 14 April 2023, J. Y. Zhang, ZY 16 ( HKAS 129859 , paratype), living culture, KUNCC 23-14156 ; • ibid., ZY 18 ( HKAS 147019 , paratype), living culture, KUNCC 23-14159 .

Additional sequence.

KUNCC 23-13865 : ITS ( PV 862363); GZCC 23-0670 : ITS ( PV 862364); KUNCC 23-14156 : ITS ( PV 862365); KUNCC 23-14159 : ITS ( PV 862366).

Notes.

Four new strains formed a phylogenetically distinct lineage within Muyocopronaceae and are described as a new genus, Cyatheomyces . Cyatheomyces synnematosus has a unique morphology, characterized by macronematous, synnematous conidiophores, which notably distinguishes it from other genera in this family, which typically have solitary, micro- or macronematous, mononematous conidiophores ( Crous et al. 2018 a; Hernández-Restrepo et al. 2019; Xu et al. 2024). The morphological characteristics are similar to species in Phaeoisaria and Rhamphoriopsis ( Hyde et al. 2018, 2019; Yang et al. 2023). However, phylogenetic analysis showed that Phaeoisaria was placed in Pleurotheciaceae , Pleurotheciales , Sordariomycetes, and Rhamphoriopsis in Rhamphoriaceae, Rhamphoriales , Sordariomycetes ( Hyde et al. 2024). Comparatively, Cyatheomyces is assigned to Muyocopronaceae ( Muyocopronales , Dothideomycetes) based on evidence from morphology and phylogeny.