Pseudopalawaniella woodwardiae J. Y. Zhang, Y. Z. Lu & K. D. Hyde, 2025

Pseudopalawaniella woodwardiae J. Y. Zhang, Y. Z. Lu & K. D. Hyde sp. nov.

Fig. 4 View Figure 4

Etymology.

The species epithet refers to this fungal host, “ Woodwardia japonica ”.

Diagnosis.

Differs from Pseudopalawania species in its shapes of ascomata (Raised vs. Flattened), asci (asci without distinct ocular chambers vs. asci with distinct ocular chambers) and ascospores (ellipsoid to broadly fusiform ascospores with obtuse ends vs. fusiform to inequilateral ascospores with pointed ends).

Holotype.

HKAS 129705 View Materials

Description.

Sexual morph: Ascomata superficial, solitary or scattered, raised, rarely flattened, sub-carbonaceous to carbonaceous, appearing as circular, flattened, covering the host, with a poorly developed basal layer and an irregular margin, dark brown to black spots, 139–189 µm × (73 –) 85–111.5 µm high ( x ̄ = 163 × 97 µm, n = 15). Ostioles central. Peridium comprising dark brown or black cells of textura angularis, 13–22.5 µm wide. Hamathecium cylindrical to filiform, septate, pseudoparaphyses, hyaline, 1–2 (– 2.6) µm wide. Asci 8 - spored, bitunicate, fissitunicate, cylindric-clavate, straight or slightly curved, sessile or inconspicuous pedicellate, apically rounded, with an inconspicuous ocular chamber, hyaline, 46–53 × 9.5–12 µm ( x ̄ = 47.5 × 10.5 µm, n = 20). Ascospores overlapping, 2–3 - seriate, ellipsoid to broadly fusiform, inequilateral, with obtuse ends, straight or slightly curved, 1 - septate, 3.5–6.5 wide at septum, constricted at the septum, with a slightly small lower cell, hyaline or subhyaline, 14.6–19.7 × 4.7–6.5 µm ( x ̄ = 17 × 5 µm, n = 20). Asexual morph: Undetermined.

Culture characteristics.

Ascospores germinating on WA within 15 h at 26 ° C. Colonies on PDA, circular with slight wavy margin, flat with protuberance and wrinkle in the center, veined, yellowish white with ashen in the center from above; beige with dark brown in the middle from below, and not producing pigmentation in cultures.

Material examined.

CHINA • Guizhou Province, Tongren City, Jiangkou County, ( 27°46'38"N, 108°45'22"E), on dead leaf axis of Woodwardia japonica ( Blechnaceae ) in a forest near the roadside, 21 May 2022, J. Y. Zhang, F 31-3 ( HKAS 129705 , holotype; GZAAS 23-0673 , isotype), ex-type living culture KUNCC 23-13877 GoogleMaps .

Additional sequence.

ITS ( PV 862367).

Notes.

Pseudopalawaniella resembles Pseudopalawania in superficial, sub-carbonaceous to carbonaceous ascomata covering the host, cylindric-clavate asci with an ocular chamber, and hyaline, 1 - septate ascospores ( Mapook et al. 2020 b). However, they are phylogenetically distinct and also differ in the shapes of their ascomata (raised vs. flattened), asci (asci without distinct ocular chambers vs. asci with distinct ocular chambers), and ascospores (ellipsoid to broadly fusiform ascospores with obtuse ends vs. fusiform to inequilateral ascospores with pointed ends). Multigene phylogenetic analysis shows that Pseudopalawaniella woodwardiae forms an independent clade within Muyocopronaceae , sister to Cyatheomyces synnematosus , with good bootstrap support (100 % ML / 1.00 PP, Fig. 1 View Figure 1 ). However, we were unable to compare the morphological characteristics of these two species, as Pseudopalawaniella woodwardiae presents a sexual morph in nature, whereas Cyatheomyces synnematosus exhibits an asexual morph. Attempts were made to culture the asexual morph in Pseudopalawaniella woodwardiae and the sexual morph in Cyatheomyces synnematosus , but these attempts failed. Therefore, there is no morphological evidence to prove that the two species belong to the same genus. Furthermore, a comparison of nucleotide base pairs of LSU, ITS, RPB 2, and tef 1-α between Pseudopalawaniella woodwardiae ( HKAS 129705 ) and Cyatheomyces synnematosus ( HKAS 129699 ) showed 27 / 833 bp (3.2 %, including 3 gaps), 97 / 839 bp (11.6 %, including 42 gaps), 95 / 1079 bp (8.8 %, without gaps), and 45 / 991 bp (4.5 %, without gaps) differences. Hence, to avoid taxonomic confusion, we introduce Pseudopalawaniella as a new genus in Muyocopronaceae ( Muyocopronales ). Further morphological investigations, together with more collections and molecular data, are needed to clarify the status of these two genera.