The genus Poaceascoma, first introduced by Phookamsak and Hyde (2015) in Phookamsak et al. (2015), as saprobic fungal group on Poaceae and Po. helicoides was designated as the type of the genus. Currently, 17 species are recognized in MycoBank (Accession date: March 10, 2025) for Poaceascoma. Poaceascoma species are usually characterized by semi-immersed to erumpent, globose to subglobose ascomata with short to long papillae, often surrounded by a turf-like structure (Phookamsak et al. 2015). Ascus fissitunicate, bitunicate, elongate-cylindrical usually contain eight filiform, hyaline, multi-septate ascospores. Poaceascoma species are mainly reported from Thailand, but have recently also been recorded from Australia, China, Hungary, South Korea and Taiwan (Hyde et al. 2018; Imrefi et al. 2024; Liu et al. 2025). These species are mainly reported from dead stems or roots of herbaceous plants (Poaceae) or submerged wood in freshwater ecosystems (Phookamsak et al. 2015; Luo et al. 2016; Crous et al. 2020; Boonmee et al. 2021; Zang et al. 2023).

TAIWAN • Guanshan Township, Taitung County, 23°02'17.6"N, 121°11'26.3"E, serpentine soil in rice field, 3^rd November 2022, K.W. Cheng, holotype, NTUPPMH 22-216 (Permanently preserved in a metabolically inactive state), ex-holotype NTUPPMCC 22-222.

Named after the serpentine soil from which the species was isolated.

Sexual morph undetermined. Asexual morph Conidiophores submerged in WA, hyaline, flexuous, rarely straight, septate, sometimes branched, 10–25 µm. Conidiogenous cells hyaline to pale brown, holoblastic, monoblastic, terminal, occasionally intercalary, subcylindrical to swollen. Conidia hyaline to pale brown when immature, brown to dark brown when mature, ellipsoidal to broadly ellipsoidal or ovoid, finely verrucose, 3–5 septate, 31.3–48.6 µm × 12–15.7 µm (x̄ = 37.8 × 14 µm, L/W ratio = 2.72, n = 30). Chlamy­dospores brown to dark brown, dumb-bell-shaped, terminal, straight or sometimes curved, occasionally branched, 108–163 µm in length, 8–15 µm in width.

Colony exhibits slow growth, reaching 35 mm diam with pale gray, fluffy to floccose surface and smooth margins. Reverse side of the colony showed a central brownish color that gradually fades into a lighter beige ring toward the edges.

This study describes Poaceascoma serpentinum as a novel fungal species based on a single strain (NTUPPMCC 22-222) isolated from serpentine soil. In our phylogenetic tree, Poaceascoma serpentinum forms a distinct clade within the genus Poaceascoma (Fig. 4). Moreover, Po. serpentinum exhibits significant genetic divergence from its closest relatives, the ex-type strain of Po. koreanum (CMML 20-44) and Po. magnum (CMML 20-47) with 83.6% and 87.4% identity in the ITS region (414/495 bp, including 24 gaps; 414/492, including 10 gaps). For tef-1, the identities are 840/890 (94.4%) and 849/890 (95.4%), respectively. Previously, species in this genus have been described solely based on their sexual stage or chlamydospore-like structures with no documented asexual stage (Zang et al. 2023; Liu et al. 2025). However, in the present study, we observed only the asexual stage of NTUPPMCC 22-222 but did not observe any sexual stage of the fungus even when carnation leaves were used as the substrate (Fig. 3). As a result, morphological comparisons between NTUPPMCC 22-222 and its closely related species are not possible. While this study establishes Po. serpentinum as a distinct species, future studies should aim to recover additional isolates from similar environments to further validate its phenotypic variation and ecological distribution. Notably, this study is also the first to document the asexual morphology of a Poaceascoma species.

Figure 3. 

Morphology of Poaceascoma serpentinum NTUPPMCC 22-222. A, B 14-days-old colony on PDA; C, G–M Immature and mature conidia; D–F Chlamydospores. Scale bars: 0.2 mm (C); 20 µm (D–G); 10 µm (H–M).

Figure 4. 

Maximum likelihood (ML) phylogenetic tree based on a concatenated dataset of ITS, LSU, SSU, and tef-1. In total, 32 strains representing 26 taxa were included in the concatenated dataset, with 3357 characters (ITS 606 bp, LSU 840 bp, SSU 1021 bp, and tef-1 890 bp) including alignment gaps. The tree was rooted with Multiseptospora thailandica MFLUCC 11-0183. MLB ≥ 70% and BPPs ≥ 0.95 were shown at each node; values lower than these thresholds are indicated by a hyphen (–). The scale bar indicates the number of estimated substitutions per site. The strains introduced in this study are in red and novel species are in bold. The ex-type strains are marked with ^T.

The genus Pseudoxylomyces was introduced by Tanaka and Hiray (2015) as a saprobic genus in habitat on submerged wood and typified with Ps. elegans (Goh et al. 1997; Tanaka et al. 2015). Currently, only two species are recognized in MycoBank (Accession date: March 10, 2025) for Pseudoxylomyces. To date, species of Pseudoxylomyces have only been described based on their asexual morphs. These species are characterized by brown, septate conidiophores that may be branched or absent and by holoblastic conidiogenous cells. The conidia are usually solitary, yellowish or orange brown to dark brown, broadly ellipsoidal or fusiform with several transverse septa of thick-walled, with paler end cells and without sheath or appendages (Tanaka et al. 2015; Dong et al. 2020). However, this group has a wide distribution and has been reported from Australia, Brazil, Hong Kong, India, Japan, Seychelles, Thailand and USA (Dong et al. 2020). The majority of the isolates reported for this genus were derived from the submerged wood in the aquatic environment (Dong et al. 2020).

Sexual morph undetermined. Asexual morph Conidia produced on carnation leaves and on the surface or submerged in WA. Conidiophores short (7–13.5 µm) or absent. Conidiogenous cells holoblastic. Conidia solitary, orange-brown when immature, turn brown in mature, occasionally with paler end cells in pale brown, broadly fusiform, most 5 thick and obvious septa (few 3–4 septa), rough, thick-walled, 37.6–50 µm × 11.8–17 µm (x̄ = 44 × 14.5 µm, L/W ratio = 3.05, n = 20).

Colony reaching 30 mm diam with dark grayish-brown in the center, pale brown to gray in margin, velvety, rough surface, entire edge, and similar to reverse side of the colony.

TAIWAN • Wanrung Township, Hualien County, 23°42'40.3"N, 121°24'48.2"E, serpentine soil in rice field, 2^nd November 2022, K.W. Cheng, living culture NTUPPMCC 22-223.

Pseudoxylomyces aquaticus was previously documented on submerged wood in Thailand. Our study recovered a single strain (NTUPPMCC 22-223) that clustered in a strongly supported clade (100%/1.00) with the ex-type strain (KUMCC 17-0312) established by Dong et al. (2020), confirming its identity as Ps. aquaticus (Fig. 6). In this study, we observed the immature conidia with 3 to 4 septa showing more orange-brown in color (Fig. 5C, D), a feature not described in previous study (Dong et al. 2020). In addition, this is the first discovery of the Pseudoxylomyces species in Taiwan.

Figure 5. 

Morphology of Pseudoxylomyces aquaticus NTUPPMCC 22-223. A, B 14-days-old colony on PDA; C, D Immature conidia and conidiophores; E, F Conidia. Scale bars: 20 µm (C–F).

Figure 6. 

Maximum likelihood (ML) phylogenetic tree based on a concatenated dataset of ITS, LSU, SSU, and tef-1. In total, 12 strains representing seven taxa were included in the concatenated dataset, with 2920 characters (ITS 526 bp, LSU 845 bp, SSU 643 bp, and tef-1 906 bp) including alignment gaps. The tree was rooted with Corynespora cassiicola CBS 100822. MLB ≥ 70% and BPPs ≥ 0.95 were shown at each node; values lower than these thresholds are indicated by a hyphen (–). The scale bar indicates the number of estimated substitutions per site. The strains introduced in this study are in red and novel species are in bold. The ex-type strains are marked with ^T.

The genus Pyrenochaetopsis was introduced by de Gruyter et al. (2010), as a saprobe on Poaceae and typified with Py. leptospora. Currently, 27 species are recognized in MycoBank (Accession date: March 10, 2025) for Pyrenochaetopsis. Pyrenochaetopsis species have been described based on either their sexual or asexual stages or both. The asexual stage is characterized by olivaceous to olivaceous-black or pale brown to brown, solitary to confluent, superficial or submerged, globose to subglobose pycnidial conidiomata that may have a non-papillate or papillate ostiolar neck. The pycnidial wall, composed of textura angularis or textura globulosa, is pseudoparenchymatous and often bears setae. Conidiogenous cells are phialidic, hyaline, and born on acropleurogenous conidiophores. The conidia are aseptate, hyaline, ovoid to cylindrical or oblong, smooth-walled and guttulate (de Gruyter et al. 2010; Valenzuela-Lopez et al. 2018; Samarakoon et al. 2024). The sexual stage is represented by brown to dark brown or dark grey to black, globose to subglobose, solitary or scattered, superficial or immersed to semi-immersed ascomata with short papillate ostiole covered with reddish-brown setae, and a pseudoparenchymatous peridium composed of dark brown, textura angularis to textura prismatica. Asci are cylindric-clavate, fissitunicate, bitunicate and eight-spored. Ascospores are hyaline to pale brown, yellowish-brown, or yellowish-gray, fusiform to oblong in shape, smooth-walled, and three- to four-septate (Mapook et al. 2020; Phookamsak et al. 2022; Absalan et al. 2024). These species are widely distributed around the world and can be found in diverse ecological niches, functioning as saprobes, endophytes, or pathogens (de Gruyter et al. 2010; Surono et al. 2023). However, most of the species are associated with plant debris, soil, or dung while some have also been discovered on opportunistic infections in nematode cysts or human tissues (Valenzuela-Lopez et al. 2018).

Sexual morph undetermined. Asexual morph Conidiomata 128–219 µm, pycnidial, globose to subglobose, dark brown, ostiolate, with dark brown, septate setae, superficial on WA and carnation leaves. Pycnidial wall textura angularis, septate setae, brown, pseudoparenchymatous cells. Conidiogenous cells hyaline, phialidic, smooth-walled, 3.6–5.0 µm × 2.9–4.1 µm (x̄ = 4.1 × 3.5 µm, n = 30). Conidia hyaline, cylindrical to ellipsoidal, aseptate, with 2 small guttules, 3.7–4.7 µm × 1.5–2.1 µm (x̄ = 4.2 × 1.8 µm, L/W ratio = 2.4, n = 30).

Colony exhibit slow growth, reaching 28 mm diam with pale gray, floccose surface, smooth margins, and medium-gray on the reverse side of the colony.

TAIWAN • Wanrung Township, Hualien County, 23°42'41.2"N, 121°24'41.8"E, serpentine soil in rice field, 2^nd November 2022, K.W Cheng, living culture NTUPPMCC 22-227.

In the present study, strain NTUPPMCC 22-227 identified as Pyrenochaetopsis paucisetosa, clustering in a strongly supported clade (100%/1.00) with the type strain of Py. paucisetosa (UTHSC DI16-193) in multi-gene phylogeny analysis (Fig. 8; Valenzuela-Lopez et al. 2018). Previous reports indicate that Py. paucisetosa has been isolated from a human toe nail in USA (Valenzuela-Lopez et al. 2018) and from freshwater sediment in Korea (Goh et al. 2020). The culture characteristics of NTUPPMCC 22-227 on PDA were similar to those of the ex-holotype of Py. paucisetosa (UTHSC DI16-193). However, the conidia of Py. paucisetosa NTUPPMCC 22-227 in our study were more elongated than previous reports (x̄ = 4.2 × 1.8 µm versus 3.6 × 1.9 µm) (Fig. 7; Valenzuela-Lopez et al. 2018; Goh et al. 2020). Furthermore, this is the first record of Py. paucisetosa in Taiwan, as well as its first occurrence in paddy field soil.

Figure 7. 

Morphology of Pyrenochaetopsis paucisetosa NTUPPMCC 22-227. A, B 14-days-old colony on PDA; C Conidiomata; D Squashed conidiomata; E Conidiogenous cells; F–H Conidia. Scale bars: 0.2 mm (C); 0.1 mm (D); 10 µm (E, F); 5 µm (G, H).

Figure 8. 

Maximum likelihood (ML) phylogenetic tree based on a concatenated dataset of ITS, LSU, rpb2, and tub2. In total, 52 strains representing 29 taxa were included in the concatenated dataset, with 2453 characters (ITS 451 bp, LSU 845 bp, rpb2 815 bp, and tub2 342 bp) including alignment gaps. The tree was rooted with Neopyrenochaetopsis hominis CBS 143033. MLB ≥ 70% and BPPs ≥ 0.95 were shown at each node; values lower than these thresholds are indicated by a hyphen (–). The scale bar indicates the number of estimated substitutions per site. The strains introduced in this study are in red and novel species are in bold. The ex-type strains are marked with ^T.

Sexual morph undetermined. Asexual morph Sporulation difficult on PDA and MEA, conidiomata produced on carnation leaves and on the surface or submerged in WA. Conidiomata 140–196 µm, pycnidial, brown, globose to subglobose, ostiolate, superficial on WA and carnation leaves, with dark brown, septate setae. Pycnidial wall textura angularis to globulosa, brown, pseudoparenchymatous cells. Conidiogenous cells hyaline, phialidic, smooth-walled, and hard to distinguish from the pycnidial wall 3.3–5.6 µm × 3.0–4.6 µm (x̄ = 4.4 × 3.5 µm, n = 30). Conidia hyaline, cylindrical to ellipsoidal, aseptate, with 2 small but obvious guttules, 3.6–5.1 µm × 1.7–2.5 µm (x̄ = 4.3 × 2.2 µm, L/W ratio = 2.03, n = 50).

Colony reaching 45 mm diam with greenish-gray, flat, velvety to floccose surface and smooth margins, and similar to reverse side of the colony.

TAIWAN • Wanrung Township, Hualien County, 23°42'40.3"N, 121°24'48.2"E, serpentine soil in rice field, 2^nd November 2022, K.W Cheng, living culture NTUPPMCC 22-228 to 242.

Pyrenochaetopsis oryzicola was originally reported from dead panicles of Oryza sativa in paddy fields in Thailand (Absalan et al. 2024). In the present, in both single- and multi-gene phylogenetic analyses showed that strains from NTUPPMCC 22-228 to 242 isolated in this study, grouped with the clade containing the ex-type strain of Py. oryzicola (MFLUCC 24-0042) (Fig. 8). Consequently, these strains were identified as Pyrenochaetopsis oryzicola. Their culture characteristics on PDA, along with conidial morphology, were consistent with those of the epitype of Py. oryzicola (MFLU 24-0319). However, the conidiogenous cells of Py. oryzicola NTUPPMCC 22-229 isolated in our study were larger than those reported in the previous study (x̄ = 4.5 × 3.5 µm versus 1.5 × 1.0 µm) (Fig. 9; Absalan et al. 2024).

Figure 9. 

Morphology of Pyrenochaetopsis oryzicola NTUPPMCC 22-229. A, B 14-days-old colony on PDA; C Conidiomata; D Squashed conidiomata; E Conidiogenous cells; F Conidia. Scale bars: 0.5 mm (C); 0.1 mm (D); 10 µm (E, F).

Crous and Zhang (2014) introduced the genus Setophaeosphaeria to accommodate Se. hemerocallidis isolated from leaf of Hemerocallis fulva (Crous et al. 2014). Currently, eight species are recognized in MycoBank (Accession date: March 10, 2025) for Setophaeosphaeria. Setophaeosphaeria species have been recorded from both sexual and asexual stage. Conidiomata are pycnidial, brown, globose, immersed or erumpent with central ostiole. Pycnidial wall is brown with 2–3 or 6–8 layers of textura angularis, pale brown or brown. Setae brown or pale brown, septate, unbranched, flexuous, smooth with obtuse ends. Conidiophores are reduced to conidiogenous cells. Conidiogenous cells are hyaline, ampulliform, smooth, proliferating several times percurrently at apex, lining the inner cavity. Conidia are hyaline, cylindrical or subcylindrical, smooth, guttulate, aseptate with obtuse ends (Crous et al. 2014, 2017, 2018b; Zhang et al. 2020). Ascomata are globose, immersed on host, subepidermal with central ostiole consists of 2–3 layers of brown textura angularis peridium. Asci are eight-spored, bitunicate, subcylindrical to narrowly ellipsoidal, stipitate containing pale brown or hyaline, fusoid-ellipsoidal, aseptate or septate, smooth ascospores (Crous et al. 2014, 2018b). Setophaeosphaeria species are widely distributed and have been reported from Australia, Brazil, China, Italy, Netherlands, and South Korea (Crous et al. 2017, 2018b; Choi et al. 2024; Liu et al. 2024). However, most of these strains were isolated from the leaf spots and branch dieback (Liu et al. 2024).

Sexual morph undetermined. Asexual morph Conidiomata 170–240 µm, pycnidial, brown, globose, ostiolate, submerged or superficial on PDA. Setae brown, straight to slightly curved, thick-walled, smooth, septate, up to 160–250 µm long, 3.5–4.0 µm wide at broadest part. Pycnidial wall textura angularis to globulosa, brown to dark brown, multi-layers. Conidiogenous cells hyaline, subglobose, smooth-walled, 3.3–4.5 µm × 2.3–3.5 µm (x̄ = 3.9 × 2.9 µm, n = 15). Conidia hyaline, cylindrical, obtuse ends, aseptate, with 2 small but obvious guttules, 3.2–4.0 µm × 1.3–1.7 µm (x̄ = 3.7 × 1.4 µm, L/W ratio = 2.54, n = 30).

Colony reaching 35 mm diam with dark grayish-green in center, beige in margin, velvety, entire edge, and similar to reverse side of the colony.

TAIWAN • Guanshan Township, Taitung County, 23°02'12.8"N, 121°11'22.0"E, serpentine soil in rice field, 2^nd November 2022, K.W Cheng, living culture NTUPPMCC 22-225 and NTUPPMCC 22-226.

The strains named NTUPPMCC 22-225 and NTUPPMCC 22-226 isolated in the present study clustered with ex-type strain Setophaeosphaeria microspora CGMCC 3.19301 with high statistical support, confirming their identification as Se. microspora (Fig. 11). However, Se. microspora (NTUPPMCC 22-225) exhibited smaller conidiogenous cells than the type strain CGMCC 3.19301 (3.5–4.5 µm × 2.5–3.5 µm versus 7.0–10.0 µm × 2.5–4.0 µm) (Fig. 10; Zhang et al. 2020). This study represents the first report of Setophaeosphaeria in Taiwan.

Figure 10. 

Morphology of Setophaeosphaeria microspora NTUPPMCC 22-225. A, B 14-days-old colony on PDA; C Squashed Conidiomata; D Setae; E Pycnidial wall; F, G Conidiogenous cells; H, I Conidia. Scale bars: 0.1 mm (C); 50 µm (D); 10 µm (E–I).

Figure 11. 

Maximum likelihood (ML) phylogenetic tree based on a concatenated dataset of ITS, LSU, and tub2. In total, 14 strains representing 11 taxa were included in the concatenated dataset, with 1534 characters (ITS 482 bp, LSU 773 bp, and tub2 279 bp) including alignment gaps. The tree was rooted with Pyrenochaetopsis americana UTHSC DI16-225. MLB ≥ 70% and BPPs ≥ 0.95 were shown at each node; values lower than these thresholds are indicated by a hyphen (–). The scale bar indicates the number of estimated substitutions per site. The strains introduced in this study are in red and novel species are in bold. The ex-type strains are marked with ^T.

Stolk (1955) introduced Westerdykella and typified the genus with W. ornata, which was isolated from soil in Mozambique. Currently, 14 Westerdykella species are listed in MycoBank (Accession date: March 10, 2025), which have been recorded worldwide on a wide range of substrates including dung, plant debris, soil, and water (Chethana et al. 2021). However, there have also been rare reports of W. dispersa isolated from neutropenic and critically burned patients in hospitals (Sue et al. 2014; Lipovy et al. 2018). Most species in Westerdykella have been described based on the presence of the sexual morph. However, some species, such as W. dispersa, form both the sexual and asexual morphs in the same culture medium (Clum 1955). Westerdykella species form superficial or submerged, globose to subglobose, or globose to irregular-elongate, olive to olive-black, or brown to dark brown, conidiomata with ostiole. The conidia are hyaline, globose to oval or pyriform, and born on simple, short conidiophores (Rai and Tewari 1963; Zimowska 2007; Chethana et al. 2021). They form superficial or submerged, globose to subglobose in ascomata sexual stage. The peridium of the ascoma is single-layered, consisting of brown textura angularis. Asci are globose to subglobose or pyriform, hyaline when immature, becoming brown at maturity. Ascospores vary in shapes (reniform, globose, or ellipsoidal) and are hyaline to pale brown or brown, guttulate, with ascospore segments separating as soon as they become visible (Rai and Tewari 1963; Ito and Nakagiri 1995; Ebead et al. 2012; Song et al. 2020; Goh et al. 2021).

Sexual morph Cleistothecia superficial or submerged on central region of PDA, 150–291 µm diam, globose to subglobose, glabrous, dirty gray when immature, black when mature. Peridium single-layered, brown, translucent, membranous, angular cells. Asci subglobose to ovoid, hyaline when immature, brown when mature, 32-spored, 12.2–16.3 µm × 10.7–14.7 µm (x̄ = 14.3 × 12.6 µm, L/W ratio = 1.15, n = 30). Ascospores ellipsoidal, smooth, subhyaline to light brown, 1 to 2 guttules, no germ-slits, 4.7–5.9 µm × 2.2–3.3 µm (x̄ = 5.1 × 2.8 µm, L/W ratio = 1.87, n = 50). Asexual morph undetermined.

Colony exhibits rapid growth, reaching 90 mm daim with a slightly diffused edge, flat and fluffy, predominantly creamy white, with a central region transitioning to pale yellow, reverse yellow to dark yellow in the central region due to the presence of cleistothecia.

TAIWAN • Guanshan Township, Taitung County, 23°02'17.6"N, 121°11'26.3"E, serpentine soil in rice field, 3^rd November 2022, K.W. Cheng, living culture NTUPPMCC 22-248 to 251.

Westerdykella aquatica has been reported from rice field mud and stems of Acorus calamus in China (Song et al. 2020), river sediment in Korea (Goh et al. 2021), and Polygonum acuminatum Kunth root in Brazil (Pietro-Souza et al. 2017; Senabio et al. 2023). In the present study, multi-gene phylogeny indicated that our strains NTUPPMCC 22-248 to 251 grouped with the clade representing W. aquatica (Fig. 13). Especially, similar to previous studies (Song et al. 2020; Goh et al. 2021), only the sexual stage was observed for all the strains identified as W. aquatica in the present study (Fig. 12). Distinguishing W. aquatica from its phylogenetically closely related species, W. purpurea based solely on sexual-stage morphology can be challenging. This is the first report of W. aquatica in Taiwan.

Figure 12. 

Morphology of Westerdykella aquatica NTUPPMCC 22-251. A, B 14-days-old colony on PDA; C Ascomata; D Squashed ascomata; E Peridium; F, G Immature asci; H Ascus; I Ascospores. Scale bars: 0.5 mm (C); 50 µm (D); 25 µm (E); 10 µm (F–I).

Figure 13. 

Maximum likelihood (ML) phylogenetic tree based on a concatenated dataset of ITS, LSU, and tub2. In total, 56 strains representing 17 taxa were included in the concatenated dataset, with 2314 characters (ITS 459 bp, LSU 865 bp, and tub2 990 bp) including alignment gaps. The tree was rooted with Preussia funiculata Huhndorf 2577 and P. typharum CBS 107.69. MLB ≥ 70% and BPPs ≥ 0.95 were shown at each node; values lower than these thresholds are indicated by a hyphen (–). The scale bar indicates the number of estimated substitutions per site. The strains introduced in this study are in red and novel species are in bold. The ex-type strains are marked with ^T.

Sexual morph undetermined. Asexual morph Conidiomata 95–198 µm, globose, subglobose to irregular due to fusion of two or more, glabrous, dark brown, ostiolate, mostly superficial, some submerged in PDA. Conidia borne terminally in camel brown gelatinous mass, ellipsoidal, some globose, smooth, hyaline, 1 to 2 guttules, 3.0–4.1 µm × 2.4–3.4 µm (x̄ = 3.5 × 2.8 µm, L/W ratio = 1.3, n = 50.

Colony exhibit rapid growth, reaching 90 mm daim with a uniform surface and smooth margins, forming a concentric pattern. The central region appears light grayish-brown due to dense conidiomata, while the edges exhibit a translucent beige hue.

TAIWAN • Wanrung Township, Hualien County, 23°42'40.3"N, 121°24'48.2"E, serpentine soil in rice field, 2^nd November 2022, K.W. Cheng, living culture NTUPPMCC 22-253 and NTUPPMCC 22-254.

Westerdykella capitulum has been reported from various environments, including saline soil in India (Pawar et al. 1967), root of motherwort (Leonurus cardiaca) in Poland (Zimowska 2007), and mudflat in Korea (Genomic data) (Heo et al. 2019). In our study, two strains (NTUPPMCC 22-253 and 22-254) were recovered and clustered in a strongly supported clade (99%/1.00) with reference strains CBS 354.65 and CBS 355.65, confirming their identity as W. capitulum (Fig. 13). Morphological characters of the representative strain of W. capitulum NTUPPMCC 22-253 used in this study are similar to W. capitulum reported by de Gruyter et al. (2012). Similar to previous studies, only the asexual stage was observed for strains identified as W. capitulum in the present study (Fig. 14; Pawar et al. 1967; de Gruyter and Noordeloos 1992; Zimowska 2007). This is the first report of W. capitulum in Taiwan.

Figure 14. 

Morphology of Westerdykella capitulum NTUPPMCC 22-253. A, B 14-days-old colony on PDA; C Conidiomata; D Squashed conidiomata; E Ostiolate; F Conidia. Scale bars: 0.2 mm (C) 20 µm; (D, E); 10 µm (F).

Sexual morph Cleistothecia 187–296 µm diam, globose to subglobose, glabrous, dark brown to black when mature, superficial or submerged in PDA. Peridium single-layered, light brown, translucent, membranous, angular cells. Asci subglobose to ovoid, hyaline when immature, brown when mature, 32-spored, 11.0–13.6 µm × 9.7–11.8 µm (x̄ = 12.3 × 10.8 µm, L/W ratio = 1.14, n = 30). Ascospores ellipsoidal, smooth, subhyaline to light brown, 2 guttules, no germ-slits, 1.8–2.7 µm × 3.7–4.5 µm (x̄ = 2.3 × 4.0 µm, L/W ratio = 1.82, n = 50). Asexual morph Conidiomata abundant on PDA at 25 °C, 7 days post-inoculation, 44–88 µm, globose, subglobose to irregular due to fusion of two or more, glabrous, brown, ostiolate, superficial. Conidia borne terminally in camel brown gelatinous mass, ellipsoidal, subglobose, some pyriform, smooth, hyaline, 0 to 2 guttules, 1.8–2.7 µm × 3.1–4.0 µm (x̄ = 2.1 × 3.3 µm, L/W ratio = 1.62, n = 50).

Colony exhibit rapid growth, reaching 80 mm daim with slightly diffuse and beige margins, yellow to pale orange pigmentation radiating outward in a concentric ring pattern, texture velvety to slightly cottony. The cleistothecia and abundant conidiomata caused the center to appear black or dark yellow.

TAIWAN • Guanshan Township, Taitung County, 23°02'12.8"N, 121°11'22.6"E, serpentine soil in rice field, 3^rd November 2022, K.W. Cheng, living culture NTUPPMCC 22-260 to 270.

Westerdykella dispersa have a global distribution and have been isolated from diverse substrates, including soil from the Netherlands and Nigeria (Arenal et al. 2007), freshwater ecosystem sediments in Brazil and Korea (da Silva et al. 2003; Goh et al. 2021), marine sediments in China and Spain (Xu et al. 2017; Guerra-Mateo et al. 2024), as endophytes of Phragmites australis in Italy (Angelini et al. 2012), and in rare cases, isolated from a neutropenic patient (Clum 1955; Sue et al. 2014). In the multi-locus phylogenetic analysis conducted in this study, strains identified as W. dispersa were separated into three distinct clusters designated as Clades A, B, and C (Fig. 13). Strains NTUPPMCC 22-260, 22-261, 22-263 and 22-266 grouped with the ex-type strain of W. dispersa (CBS 297.56) in Clade B. Two other representative strains, CBS 390.61 and CBS 288.67, along with our strains NTUPPMCC 22-262, 22-264, 22-265, and 22-267 to 22-270, formed a separate clade (Clade C), which is sister to the main W. dispersa lineage. Additionally, strain CBS 508.75 formed a basal clade (also referred to as Clade A) relative to Clades B and C, complicating the delineation of precise species boundaries. When comparing sequence identity, the representative strain NTUPPMCC 22-269, which clusters in Clade C, showed 97.6% similarity (925/948 bp) in the tub2 gene to the ex-type strain of W. dispersa (CBS 297.56). This strain also formed a strongly supported clade (80% bootstrap support) sister to the clade containing the ex-type strain in single gene phylogeny of tub2 (See Suppl. material 2: fig. S1). However, no significant genetic divergence was observed between these strains in the ITS and LSU regions (ITS: 433/437 bp, identities 99.1%, including 3 gaps; LSU: 824/830 bp, identities 99.4%, including 4 gaps). As shown in Fig. 15, although PDA cultures exhibited slight variation in colony coloration (NTUPPMCC 22-266 representing Clade B and NTUPPMCC 22-269 representing Clade C; yellow to pale orange versus grayish-white to pale gray-green), other micromorphological features did not show notable differences (See Suppl. material 1: table S4). Additionally, relying solely on culture characteristics is not a reliable method for delineating fungal species (Jeewon and Hyde 2016). Therefore, based on molecular similarity, phylogenetic placement, and morphological consistency, we tentatively identify strains in three clades as W. dispersa. The observed genetic variation may be related to their geographical origin or the specific habitats from which these strains were isolated. Consistent with previous studies (Sue et al. 2014), both sexual and asexual stages were observed in culture for W. dispersa in the present study. This report represents the first record of W. dispersa in Taiwan.

Figure 15. 

Morphology of Westerdykella dispersa NTUPPMCC 22-266. A, B 14-days-old colony on PDA; C Ascomata (red arrow) and conidiomata (blue arrow); D Squashed ascomata; E Conidiomata and ostiolate; F Peridium; G Asci; H Ascospores; I Conidia. Morphology of Westerdykella dispersa NTUPPMCC 22-269. J, K 14-days-old colony on PDA; L Ascomata (red arrow) and conidiomata (blue arrow); M Ascospores; N Conidia. Scale bars: 0.5 mm (C, L); 0.1 mm (D); 20 µm (E–G, M); 10 µm (H, I, N, O).

TAIWAN • Wanrung Township, Hualien County, 23°42'40.3"N, 121°24'48.2"E, serpentine soil in rice field, 2^nd November 2022, K.W Cheng, holotype, NTUPPMH 22-218 (Permanently preserved in a metabolically inactive state), ex-holotype NTUPPMCC 22-255, ex-isotype NTUPPMCC 22-256 to 259.

Named after Formosa, the former name of Taiwan, where the type specimen was collected.

Sexual morph Cleistothecia 250–430 µm diam, non-ostiolate, globose, glabrous, mostly superficial, some submerged in PDA, dirty gray when immature, black when mature. Peridium single-layered, brown, translucent, membranous, angular cells. Asci subglobose to globose, hyaline when immature, 32-spored, 15.7–21.0 µm × 14.6–18.4 µm (x̄ = 18.3 × 16.3 µm, L/W ratio = 1.1, n = 30). Ascospores ellipsoidal, smooth, subhyaline to light brown, 1 to 3 guttules, no germ-slits, 3.4–6.4 µm × 1.8–3.2 µm (x̄ = 5.2 × 2.6 µm, L/W ratio = 2.01, n = 50). Asexual morph undetermined.

Colony exhibits rapid growth, reaching 80 mm diam with flat, sparse aerial mycelium, creamy white, surface and margins smooth, pale gray in central region due to the presence of cleistothecia.

Westerdykella formosana forms a distinct clade in our phylogenetic analysis (Fig. 13 and Suppl. material 2: figs S1, S2). The ex-type strain of W. formosana (NTUPPMCC 22-255) exhibits significant genetic divergence from its closest relative, the ex-type strain of W. aquatica (JAUCC 1788), with 94.7% identity in the ITS region (392/414 bp, including 1 gap), and from the representative strain PY1 of W. aquatica in the tub2 gene (96.7% identity; 857/886 bp). Morphologically, W. formosana produces larger asci but smaller ascospores compared to its phylogenetically closest relative, W. aquatica (x̄ = 18.3 × 16.3 µm versus 15.3 × 14.1 µm; x̄ = 5.2 × 2.6 µm versus 6.5 × 2.9 µm). Additionally, W. formosana lacks the yellow hue observed in PDA cultures of W. aquatica (Fig. 16; Song et al. 2020). Based on molecular, morphological, and cultural differences, we propose our five strains (NTUPPMCC 22-255 to 22-259) as a novel species, Westerdykella formosana. Further morphological comparisons with other Westerdykella species are provided in Suppl. material 1: table S4.

Figure 16. 

Morphology of Westerdykella formosana NTUPPMCC 22-255. A, B 14-days-old colony on PDA; C Ascomata; D Immature ascoma; E Squashed ascomata; F Peridium; G, H Immature ascus; I Ascus; J, L Ascospore; K Immature ascospore. Scale bars: 100 µm (C, E); 200 µm (D); 20 µm (F–J); 5 µm (K, L).

Sexual morph Cleistothecia clustered in submerged regions in PDA, 106–185 µm diam, globose to subglobose, dirty gray when immature, dark brown to black when mature. Asci subglobose to ovoid, hyaline when immature, greenish brown when mature, 32-spored, edges slightly irregular due to crowding of mature ascospores, 26.9–40.2 µm × 20.8–29.8 µm (x̄ = 32.7 × 24.5 µm, L/W ratio = 1.35, n = 30). Ascospores mostly globose, some subglobose, smooth, yellowish-brown, 1 to 2 guttules, 5.2–6.8 µm × 5.4–6.9 µm (x̄ = 6.1 × 5.9 µm, L/W ratio = 1.03, n = 50). Asexual morph undetermined.

Colony reaching 50 mm diam with slightly diffused edge, predominantly creamy white and partly fluffy, with only the cleistothecia cluster region turning dark brown.

TAIWAN • Guanshan Township, Taitung County, 23°02'14.8"N, 121°11'22.6"E, serpentine soil in rice field, 3^rd November 2022, K.W. Cheng, living culture NTUPPMCC 22-243 to 247.

Preussia globosa was synonymized under Westerdykella globosa by Ito (1995). This species has been reported from various environments, including soil from a stream bank and stored wheat grains in India (Rai and Tewari 1963; Kumari et al. 2019), paddy soil in Japan (Ito and Nakagiri 1995), and soil cultivated with Ganoderma lucidum in China (Zaheer et al. 2024). Our study recovered five strains (NTUPPMCC 22-243–247) that clustered in a strongly supported clade (100%/1.00) with the ex-type strain of W. globosa (IFO 32588) (Rai and Tewari 1963), confirming their identity as W. globosa (Fig. 13). The strains isolated in the present study share similar morphologies with W. globosa in producing globose, brown mature ascospores. Notably, consistent with previous studies, only the sexual stage was observed for strains identified as W. globosa in the present study. However, it is worthy to note that the asci of our strains are larger than previously reported (27–40 µm × 21–30 µm versus 20–24 µm × 14–17 µm) (Fig. 17; Ito and Nakagiri 1995). This is the first report of Westerdykella globosa in Taiwan.

Figure 17. 

Morphology of Westerdykella globosa NTUPPMCC 22-246. A, B 14-days-old colony on PDA; C Ascomata; D Immature ascomata; E Squashed ascomata; F, G Immature asci; H Ascus; I Ascospores. Scale bars: 0.1 mm (C); 50 µm (D); 20 µm (F–H); 10 µm (I).

The genus Talaromyces was first established by Benjamin (1955) and used to accommodate sexual stages of some Penicillium species. Currently, Talaromyces is the largest genus in the family Trichocomaceae, which is recorded in over 170 accepted species classified into 8 sections in Mycobank (Accession date: March 10, 2025). Talaromyces has a global distribution and has been reported from a wide range of substrates including air, indoor environments, plant materials, food products, dung, but mostly from soils (Hyde et al. 2024; Visagie et al. 2024). Some Talaromyces species play a key role as endophytes, helping plants against pathogens and promoting plant growth (Naraghi et al. 2012; Hashem et al. 2023; Nicoletti et al. 2023b). Additionally, while some species can cause diseases in humans, others show activity against human cancer cell lines (Chan et al. 2016; Zhai et al. 2016; Nicoletti et al. 2023a). In genus Talaromyces, specifically within the section Talaromyces, both asexual and sexual morphs have been recorded in some species, exhibiting considerable morphological diversity. In the asexual morph, most species possess bi-verticillate conidiophores, although some exhibit both bi-verticillate and mono-verticillate conidiophores (Nguyen et al. 2023).

Sexual morph undetermined. Asexual morph Conidiophores arose from aerial hyphae, or roping hyphal aggregations, hyaline, straight, bi-verticillate. Metulae 9.6–15.5 µm × 2.4–3.0 µm. Phialides 3–5, flask-shaped, 8.5–10.8 µm × 2.1–2.6 µm. Conidia globose to subglobose, hyaline, few pale green, 2.2–2.5 µm × 1.6–2.1 µm (x̄ = 2.3 × 1.9 µm, L/W ratio = 1.20, n = 25).

• CYA 23–25/33–38; CYAS No growth; MEA 55–58/80–85; OA 43–46/85–90; PDA 38–42/60–65; YESA 43–45/62–65.

• CYA/MEA 20 °C 28–30/30–33; 30 °C 30–33/51–56; 37 °C 16–18/16–19.

CYA, 25 °C, 14 days, sulcate, margin entire and white to buff, floccose, sporulation sparse, pale gray to grayish-green, soluble pigments absent, exudates clear droplets; reverse in coffee brown to caramel. MEA, 25 °C, 14 days, margin slightly irregular and beige, floccose to funiculose, sporulation dense, grayish-green, soluble pigments absent, exudates clear droplets; reverse in light yellowish brown. OA, 25 °C, 14 days, margin entire and pale gray, floccose to funiculose, sporulation dense, dark green, soluble pigments absent, exudates clear droplets; reverse in buff. PDA, 25 °C, 14 days, margin irregular and whitish, floccose to funiculose, sporulation dense, olive green, soluble pigments absent, exudates clear droplets; reverse in cream-buff. YESA, 25 °C, 14 days, margin slightly irregular, floccose, sporulation moderately dense, warm beige, soluble pigments and exudates absent; reverse in light gold to metallic gold.

TAIWAN • Guanshan Township, Taitung County, 23°02'12.8"N, 121°11'22.0"E, serpentine soil in rice field, 2^nd November 2022, K.W Cheng, living culture NTUPPMCC 22-271.

In the present study, our strain (NTUPPMCC 22-271) clustered within the clade containing ex-type strain, along with other representative strains of T. adpressus with strong statistical support (100%/1.00) (Fig. 19). T. adpressus NTUPPMCC 22-271 exhibited similar asexual morph to the ex-type strain of T. adpressus (CBS 140620), with bi-verticillate conidiophores, phialides 3–5, and subglobose conidia (Fig. 18); however, our strain (NTUPPMCC 22-271) did not grow on CYAS (Chen et al. 2016). T. adpressus has been reported from a wide range of substrates including sea sand, indoor air, peanut, Heterodera zeae cysts, Oryza coarctata as endophytic fungi (Chen et al. 2016; Peterson and Jurjevic 2019; Airin et al. 2023; Lee et al. 2023; Mo et al. 2024). However, this study represents the first discovery of T. adpressus in Taiwan.

Figure 18. 

Morphology of Talaromyces adpressus NTUPPMCC 22-271. A, D 14-days-old colony on PDA; B, E 14-days-old colony on MEA; C, F 14-days-old colony on CYA; G, H 14-days-old colony on YESA; I 14-days-old colony on OA; J, K Conidiophores, phialides, and conidiogenous cells; L Conidia. Scale bars: 20 µm (J, K); 10 µm (L).

Figure 19. 

Maximum likelihood (ML) phylogenetic tree based on a concatenated dataset of ITS, cmdA, rpb2, and tub2. Species representing section Talaromyces including 113 strains representing 98 taxa were included in the concatenated dataset, with 2127 characters (ITS 536 bp, cmdA 336 bp, rpb2 843 bp, and tub2 412 bp) including alignment gaps. The tree was rooted with Talaromyces helicus CBS 335.48 (Section Helici). MLB ≥ 70% and BPPs ≥ 0.95 were shown at each node; values lower than these thresholds are indicated by a hyphen (–). The scale bar indicates the number of estimated substitutions per site. The strains introduced in this study are in red and novel species are in bold. The ex-type strains are marked with ^T.

TAIWAN • Wanrung Township, Hualien County, 23°42'40.3"N, 121°24'48.2"E, serpentine soil in rice field, 2^nd November 2022, K.W Cheng, holotype, NTUPPMH 22-219 (Permanently preserved in a metabolically inactive state), ex-holotype NTUPPMCC 22-275, ex-isotype NTUPPMCC 22-273 to 274, 276 to 285.

Named after Taiwan, the country where the type specimen was collected.

Sexual morph undetermined. Asexual morph Conidiophores arose from aerial hyphae, or roping hyphal aggregations, hyaline, smooth but some slightly rough, straight, most mono-verticillate or bi-verticillate, occasionally formed subterminal side branches of mono-verticillate, 5–130 µm. Metulae 10.5–16.5 µm × 2.8–3.2 µm. Phialides most 3–5, flask-shaped, 8.2–15.6 µm × 2.0–2.8 µm, rarely mono-phialides up to 18.2 µm × 3.5 µm. Conidia globose to subglobose, few pyriform, rough surfaces and walls, hyaline in immature, pale green to green in mature, 3.3–4.6 µm × 2.9–4.0 µm (x̄ = 3.8 × 3.5 µm, L/W ratio = 1.1, n = 50).

• CYA 13–15/30–33; CYAS No growth; MEA 58–60/80–85; OA 48–50/88–90; PDA 52–57/72–75; YESA 37–40/65–72.

• CYA/MEA 20 °C 30–32/38–40; 30 °C 19–21/55–58; 37 °C 15–16/25–28.

CYA, 25 °C, 14 days, obvious sulcate, margin entire, floccose, sporulation none, pale gray to beige at center, soluble pigments absent, exudates clear small droplets; reverse in yellowish brown and caramel at center. MEA, 25 °C, 14 days, margin slightly irregular and beige, floccose to funiculose, sporulation dense, grayish-green, soluble pigments absent, exudates clear droplets; reverse in cream-buff. OA, 25 °C, 14 days, margin entire and beige, floccose to funiculose, sporulation dense, olive green, soluble pigments absent, exudates clear small droplets; reverse in buff. PDA, 25 °C, 14 days, margin entire and whitish, floccose to funiculose, sporulation dense, green, soluble pigments absent, exudates clear droplets; reverse in cream-buff. YESA, 25 °C, 14 days, margin slightly irregular, floccose, sporulation moderately dense, warm beige, soluble pigments absent, exudates clear small droplets; reverse in warm beige to copper brown.

Talaromyces taiwanensis forms a strongly supported clade (100%/0.99) with its sister species T. californicus and T. louisianensis in the multi-locus phylogeny (Fig. 19). The ex-type strain of T. taiwanensis (NTUPPMCC 22-275) shows over 98.5% sequence similarity across the ITS, rpb2, and tub2 regions when compared to the ex-type strains of T. californicus (NRRL 58168) and T. louisianensis (NRRL 35823). However, a small genetic variation is observed in the cmdA region, where T. taiwanensis exhibits 97.6% identity (325/333 bp, including 1 gap) to these sister species. Morphologically, T. taiwanensis displays conidial structure similar to T. californicus characterized by mono-verticillate and single phialides, a rare phenotypic feature in the T. sect. of Talaromyces (Fig. 20; Peterson and Jurjevic 2019). However, T. taiwanensis NTUPPMCC 22-275 formed smaller conidia to its phylogenetically closely related species T. californicus and T. louisianensis (x̄ = 3.0–5.0 µm × 3.0–4.0 µm versus 4.0–6.0 µm × 4.0–7.0 µm and versus 3.5–5.0 µm × 3.5–5.0 µm). Furthermore, T. taiwanensis demonstrates significantly slower growth (13–15 mm) compared to T. californicus (25–40 mm) and T. louisianensis (35–39 mm) and lacks sporulation on CYA (Peterson and Jurjevic 2019). Furthermore, these two species were isolated from air in USA and our samples were from serpentine soil in Taiwan (Peterson and Jurjevic 2019).

Figure 20. 

Morphology of Talaromyces taiwanensis NTUPPMCC 22-275. A, D 14-days-old colony on PDA; B, E 14-days-old colony on MEA; C, F 14-days-old colony on CYA; G, H 14-days-old colony on YESA; I 14-days-old colony on OA; J–L Conidiophores, phialides, and conidiogenous cells; M Conidia. Scale bars: 20 µm (J, K); 10 µm (L, M).

Sexual morph Ascomata solitary or clustered, superficial, globose to subglobose, yellow hyphae covered, 220–470 µm diam. Asci subglobose to ovoid, hyaline, 8.6–12.7 µm × 7.9–10.1 µm (x̄ = 10.9 × 9.6 µm, L/W ratio = 1.14, n = 15). Ascospores ellipsoidal, spiny, thick walled, 4.2–5.0 µm × 2.8–3.5 µm (x̄ = 4.6 × 3.2 µm, L/W ratio = 1.47, n = 25). Asexual morph Conidiophores straight, bi-verticillate, smooth walled and long stipes, up to 300 µm. Metulae 9.1–14.0 µm × 2.5–2.8 µm. Phialides 3–6, flask-shaped, 8.1–12.5 µm × 2.2–2.5 µm. Conidia globose to subglobose, smooth walled, hyaline to pale brownish green, 2.0–2.8 µm × 1.6–2.4 µm (x̄ = 2.4 × 2.0 µm, L/W ratio = 1.20, n = 25).

• CYA 35–38/58–61; CYAS 15–17/31–33; MEA 40–42/70–75; OA 39–42/85–90; PDA 38–41/70–75; YESA 30–33/43–48.

• CYA/MEA 20 °C 32–34/31–33; 30 °C 40–44/37–42; 37 °C No growth/No growth.

CYA, 25 °C, 14 days, margin entire and light yellow, floccose, sporulation dense, yellowish orange, soluble pigments absent, exudates clear droplets; reverse in orange and copper brown at center. MEA, 25 °C, 14 days, margin entire and whitish, floccose, sporulation dense, grayish-green, soluble pigments absent, exudates clear droplets; reverse in cream-buff. OA, 25 °C, 14 days, margin entire and golden yellow, floccose to funiculose, sporulation dense, orange to grayish-green and wine red at center, soluble pigments absent, exudates clear droplets; reverse in buff. PDA, 25 °C, 14 days, margin entire and light yellow, floccose, sporulation dense, yellowish orange to grayish-green, soluble pigments absent, exudates clear droplets; reverse in cream-buff. YESA, 25 °C, 14 days, slightly sulcate, margin irregular, floccose, sporulation moderately dense, yellowish orange, soluble pigments and exudates absent; reverse in orange-brown.

TAIWAN • Guanshan Township, Taitung County, 23°02'17.6"N, 121°11'26.3"E, serpentine soil in rice field, 3^rd November 2022, K.W. Cheng, living culture NTUPPMCC 22-272.

In the present study, our strain (NTUPPMCC 22-272) clustered within the clade containing ex-type strain, along with other representative strains of T. thailandensis with strong statistical support (85%/1.00) (Fig. 19). T. thailandensis (NTUPPMCC 22-272) displayed morphological features similar to the ex-type strain (CBS 133147) as reported by Manoch et al. (2013) and Yilmaz et al. (2014). Typically, these species exhibit ellipsoidal, spiny, thick-walled ascospores (sexual stage), bi-verticillate conidiophores with 3–6 phialides, and subglobose conidia (asexual stage), along with an absence of growth at 37 °C. However, our strain (NTUPPMCC 22-272) differs by presenting a distinctive red hue on OA (Fig. 21). T. thailandensis has been reported previously in Thailand as soil-derived fungus (Manoch et al. 2013; Ningsih et al. 2024). However, this study represents the first discovery of T. thailandensis in Taiwan.

Figure 21. 

Morphology of Talaromyces thailandensis NTUPPMCC 22-272. A, D 14-days-old colony on PDA; B, E 14-days-old colony on MEA; C, F 14-days-old colony on CYA; G, J 14-days-old colony on YESA; H 14-days-old colony on OA; I 14-days-old colony on CYAS; K Ascomata and conidiophores; L Asci; M Ascospores; N, O Conidiophores, phialides, and conidiogenous cells; P Conidia. Scale bars: 0.5 mm (K); 10 µm (L, N–P); 5 µm (M).

Cylindrotrichum oligospermum was originally used by (Corda) Bonord. to establish the genus Cylindrotrichum, while Reticulascus was introduced as a new genus with Reticulascus clavatus as the type species, and Cylindrotrichum clavatum as its asexual morph. Later, C. oligospermum, including C. hennebertii, was recombined and treated as a synonym of R. tulasneorum (Réblová et al. 2011). However, Réblová et al. (2016) recommended the continued use of Cylindrotrichum over Reticulascus due to its wider usage and greater number of associated names. Additionally, Blastophorum aquaticum was synonymized with Cylindrotrichum aquaticum by Luo et al. (2019). The asexual morph of Cylindrotrichum is characterized by the absence of setae. Conidiophores are cylindrical, straight to flexuous, solitary or in clusters, mononematous, and macronematous. Conidiogenous cells are usually monophialidic, rarely polyphialidic, with a hyaline to subhyaline collarette. Conidia are hyaline, cylindrical, slightly tapering with an obtuse apex, septate, guttulate, and smooth-walled (Luo et al. 2019; Crous et al. 2022). The sexual morph lacks stroma and produces superficial ascomata that are subglobose to conical, brown, and occur solitarily or in gregarious groups. The ostiolum is periphysate. Asci are eight-spored, cylindrical-clavate, unitunicate, and short-stipitate. Ascospores are hyaline, ellipsoidal to fusiform, and septate (Réblová et al. 2011; Luo et al. 2019). Cylindrotrichum (Reticulascus) strains has been reported from Australia, China, Czech Republic, France, Germany, and Netherlands as a saprobe on dead wood (Réblová et al. 2011; Luo et al. 2019; Crous et al. 2022).

TAIWAN • Guanshan Township, Taitung County, 23°02'12.8"N, 121°11'22.0"E, serpentine soil in rice field, 2^nd November 2022, K.W Cheng, holotype, NTUPPMH 22-220 (Permanently preserved in a metabolically inactive state), ex-holotype NTUPPMCC 22-287, ex-isotype NTUPPMCC 22-286.

Named after Formosa, the former name of Taiwan, where the type specimen was collected.

Sexual morph undetermined. Asexual morph Conidia produced on carnation leaves and WA. Conidiophores solitary, subcylindrical, light brown, unbranched, straight to slightly flexuous, and thick-walled. Conidiogenous cells subcylindrical, light brown to light gray, terminal or intercalary, with flared collarettes. Conidia solitary or aggregated in clusters, subcylindrical to slightly curved, with an obtuse apex, guttules, hyaline, smooth-walled, and 0 to 3-septate, 13.4–19.9 µm × 3.8–6.1 µm (x̄ = 16.3 × 4.6 µm, L/W ratio = 3.6, n = 50). Chlamydospores rusty copper-brown, circular to slightly ellipsoidal, clustered 1–3 on PDA and WA. Single chlamydospores 6.1–8.9 µm × 5.9–8.4 µm (x̄ = 7.3 × 7.2 µm, L/W ratio = 1.0, n = 50).

Colony reaching 60 mm diam with flat, spreading, gray margin and dark gray blue in the center, reverse similar.

Cylindrotrichum formosanum NTUPPMCC 22-287 is typical of Cylindrotrichum in having straight to flexuous, brown, subcylindrical conidiophores, terminal or intercalary conidiogenous cells with flared collarettes, and subcylindrical, smooth, hyaline conidia (Fig. 22; Réblová et al. 2011; Crous et al. 2022). However, our strains (NTUPPMCC 22-286 and NTUPPMCC 22-287) can be easily differentiated from its closely related species based on both phylogeny and morphology (Fig. 23). C. formosanum present a distinct clade with a strongly support (96%/1.00) as a sister group to C. parahennebertii in our multi-locus phylogenetic analysis. Moreover, the ex-type strain of C. formosanum (NTUPPMCC 22-287) exhibits significant genetic divergence from the ex-type strain of C. parahennebertii (CBS 148282) , with 84.2% identity in the ITS region (378/449 bp, including 41 gaps) and 97.3% identity in the LSU region (783/805 bp, including 2 gaps). Morphologically, C. formosanum produces larger conidia than C. parahennebertii (x̄ = 16.3 × 4.6 µm versus 13.5 × 3.8 µm). Additionally, conidia of C. formosanum are 0- to 3-septate, whereas C. parahennebertii consistently produces distinctly 3-septate conidia (Fig. 22; Crous et al. 2022). Beyond commonly observed morphological features, this study also reports a novel characteristic for Cylindrotrichum species: the presence of rusty copper-brown, circular to slightly ellipsoidal chlamydospores observed in culture (Fig. 22L). Based on these molecular and morphological differences, we propose our two strains (NTUPPMCC 22-286 and NTUPPMCC 22-287) as a novel species, Cylindrotrichum formosanum.

Figure 22. 

Morphology of Cylindrotrichum formosanum NTUPPMCC 22-287. A, B 14-days-old colony on PDA; C–G Conidiophores and conidiogenous cells giving rise to conidia; H, I Conidiophore; J Conidiogenous cells; K Conidia; L Chlamydospores. Scale bars: 20 µm (C–E, G–I, K, L); 10 µm (F, J).

Figure 23. 

Maximum likelihood (ML) phylogenetic tree based on a concatenated dataset of ITS, LSU, and SSU. In total, 16 strains representing 13 taxa were included in the concatenated dataset, with 2055 characters (ITS 475 bp, LSU 848 bp, and SSU 732 bp) including alignment gaps. The tree was rooted with Colletotrichum musae CBS 116870. MLB ≥ 70% and BPPs ≥ 0.95 were shown at each node; values lower than these thresholds are indicated by a hyphen (–). The scale bar indicates the number of estimated substitutions per site. The strains introduced in this study are in red and novel species are in bold. The ex-type strains are marked with ^T.

The genus Parasarocladium was first introduced by Summerbell et al. (2018) to accommodate three soil borne, acremonium-like species, and is typified by Pa. radiatum, which was isolated from soil in India. Currently, 15 species epithets are recognized for Parasarocladium in Mycobank (Accession date: March 10, 2025). Conidiophores of Parasarocladium species are solitary or aggregated, arising from aerial or substratal mycelium, erect, aseptate or septate, smooth, hyaline. Conidiogenous cells are phialidic, hyaline, smooth, lateral or terminal, straight or irregularly curved, monophialides or polyphialides. The conidia are hyaline, smooth, ellipsoidal to ovate, or bacilliform to fusiform, aseptate, sometimes slightly curved, forming slimy heads on the phialides (Summerbell et al. 2018; Lee et al. 2025). Parasarocladium has a global distribution and has been isolated from soil and plants as a soil borne fungus, plant pathogen, and endophyte. (Summerbell et al. 2018; Hou et al. 2023).

TAIWAN • Guanshan Township, Taitung County,23°02'17.6"N, 121°11'26.3"E, serpentine soil in rice field, 3^rd November 2022, K.W. Cheng, holotype, NTUPPMH 22-221 (Permanently preserved in a metabolically inactive state), ex-holotype NTUPPMCC 22-288.

Named after Formosa, the former name of Taiwan, where the type specimen was collected.

Sexual morph undetermined. Asexual morph Conidia were observed on WA. Conidiophores mostly solitary, phialidic, straight but some curved, smooth, hyaline, arising directly from aerial or substratal hyphe, unbranched, mono-phialides or adelophialides predominant, 7–18 × 2–3 μm. Conidia ellipsoidal, sometimes fusoid, hyaline, aseptate, smooth-walled, 1-celled, several tiny guttules, arranged in slimy heads, 3.7–7.4 µm × 2.0–3.9 µm (x̄ = 4.9 × 2.6 µm, L/W ratio = 1.94, n = 50).

Colony exhibits slow growth, reaching 35 mm diam with creamy white, radially folded, slightly rugose at center region, smooth margin, reverse pale yellow.

Parasarocladium formosum forms a distinct clade with strong support (94%/1.00), as a sister taxon to Pa. chondroidum in our multi-locus phylogenetic analysis (Fig. 25). Moreover, the ex-type strain of Pa. formosum (NTUPPMCC 22-288) shows significant genetic divergence from its closest relative, the ex-type strain of Pa. chondroidum (CBS 652.93), with 96.7% identity in the ITS region (438/453 bp, including 4 gaps) and 93.1% identity in the tef-1 gene (752/808 bp). It is worth noting that Pa. chondroidum has been reported as an endophyte in Gramineae, whereas Pa. formosum NTUPPMCC 22-288, although isolated from a paddy field, was recovered from soil and has not been identified as an endophyte (Hou et al. 2023). Moreover, the conidia of our new species are slightly larger and straighter compared to the original description of Pa. chondroidum CBS 652.93, which exhibited relatively smaller and curved conidia. (3.7–7.4 µm × 2.0–3.9 µm versus 3.4–8 µm × 1.2–2.5 µm) (Fig. 24; Hou et al. 2023). Based on these molecular and morphological differences, we propose our strain (NTUPPMCC 22-288) as a novel species, Parasarocladium formosum.

Figure 24. 

Morphology of Parasarocladium formosum NTUPPMCC 22-288. A, B 14-days-old colony on PDA; C–E Conidiophores, phialides, and conidiogenous cells; F Conidia. Scale bars: 20 µm (C); 10 µm (D–F).

Figure 25. 

Maximum likelihood (ML) phylogenetic tree based on a concatenated dataset of ITS, LSU, and tef-1. In total, 19 strains representing 17 taxa were included in the concatenated dataset, with 2159 characters (ITS 505 bp, LSU 809 bp, and tef-1 845 bp) including alignment gaps. The tree was rooted with Sarocladium ochraceum CBS 428.67. MLB ≥ 70% and BPPs ≥ 0.95 were shown at each node; values lower than these thresholds are indicated by a hyphen (–). The scale bar indicates the number of estimated substitutions per site. The strains introduced in this study are in red and novel species are in bold. The ex-type strains are marked with ^T.

The genus Sarocladium was introduced by Gams and Hawksworth (1975) to accommodate two rice (Oryza sativa) pathogens, S. oryzae and S. attenuatum, with the former as type species. Currently, 38 species epithets are recognized for Sarocladium in Mycobank (Accession date: March 10, 2025). Conidiophores of Sarocladium are mononematous, hyaline, arising from aerial mycelium, submerged hyphae or hyphal ropes. They are straight or slightly curved, mono-, poly- or adelophialidic with smooth-walls. Conidia are hyaline to subhyaline, smooth-walled, and highly variable in shape—ranging from cylindrical, bacilliform, oblong, ovoid, fusoid, and limoniform to subglobose or irregular. They are typically produced in slimy heads or dry chains. Additionally, recent studies have reported the occasional presence of crystals and chlamydospores in some species (Giraldo et al. 2015; Hou et al. 2023). Sarocladium has a global distribution (Ou et al. 2020). Species in Sarocladium have been reported as plant pathogens of rice and apple fruit and some species reported as opportunistic human pathogens, and saprophytic fungi in soil or plant debris. Furthermore, recent studies have reported them as endophytes in tropical grasses, coastal grass, and crops (Yeh and Kirschner 2014; Giraldo et al. 2015; Gonzáles-Teuber et al. 2017; Hou et al. 2019; Anjos et al. 2020; Ou et al. 2020).

TAIWAN • Guanshan Township, Taitung County, 23°02'17.6"N, 121°11'26.3"E, serpentine soil in rice field, 3^rd November 2022, K.W. Cheng, holotype, NTUPPMH 22-222 (Permanently preserved in a metabolically inactive state), ex-holotype NTUPPMCC 22-289.

Named after Formosa, the former name of Taiwan, where the type specimen was collected.

Sexual morph undetermined. Asexual morph Conidia were observed on WA. Conidiophores solitary, hyaline, straight to slightly flexuous, smooth-walled, arising from hyphal ropes or vegetative hyphae. Phialides subulate, hyaline, wide at the base, with, 13–30 µm long. Adelophialides and schizophialides not observed. Conidia unicellular, cylindrical with rounded ends, hyaline, smooth-walled, 1-celled, few with inconspicuous 1 to 2 guttules on the end(s), sometimes aggregated in clusters forming a slimy head, 3.5–5.3 µm × 1.1–2.1 µm (x̄ = 4.4 × 1.5 µm, L/W ratio = 3.08, n = 50).

Colony exhibit slow growth, reaching 35 mm diam with flat, pale orange, wrinkled in the center, slimy, and smooth margin. The reverse side of the colony displayed similar characteristics.

In the present study, Sarocladium formosanum forms a distinct clade with strong support (99%/1.00) based on multi-locus phylogenetic analysis (Fig. 27). Moreover, S. formosanum shows significant genetic divergence from its closest relatives, ex-type strain of S. strictum (CBS 346.70) and S. bactrocephalum (CBS 749.69) with 95.5% identity to S. strictum (677/710 bp) and 93.1% identity to S. bactrocephalum (661/710 bp) in the rpb2 gene. Morphologically, S. formosanum lacks adelophialides, schizophialides, and chlamydospores, which distinguishes it from S. mali (Fig. 26; Hou et al. 2019). Several Sarocladium species have been recorded in Taiwan. S. spinificis was reported as an endophyte of the coastal grass Spinifex littoreus (Yeh and Kirschner 2014), while S. attenuatum, S. oryzae, S. sparsum, and S. spirale were isolated from rice grains and leaf sheaths (Ou et al. 2020). However, our species, S. formosanum and S. serpentinicola, were isolated from serpentine environments and formed distinct clades from these previously reported species in the phylogeny. While this study establishes S. formosanum as a distinct species, future studies should aim to recover additional isolates from similar environments to further validate its phenotypic variation and ecological distribution.

Figure 26. 

Morphology of Sarocladium formosanum NTUPPMCC 22-289. A, B 14-days-old colony on PDA; C–E Conidiophores and phialides; F Conidia. Scale bars: 10 µm (C–F).

Figure 27. 

Maximum likelihood (ML) phylogenetic tree based on a concatenated dataset of ITS, LSU, rpb2, and tef-1. In total, 45 strains representing 38 taxa were included in the concatenated dataset, with 2821 characters (ITS 497 bp, LSU 779 bp, rpb2 734 bp, and tef-1 811 bp) including alignment gaps. The tree was rooted with Parasarocladium breve CBS 150.62. MLB ≥ 70% and BPPs ≥ 0.95 were shown at each node; values lower than these thresholds are indicated by a hyphen (–). The scale bar indicates the number of estimated substitutions per site. The strains introduced in this study are in red and novel species are in bold. The ex-type strains are marked with ^T.

TAIWAN • Guanshan Township, Taitung County, 23°02'14.8"N, 121°11'22.6"E, serpentine soil in rice field, 3^rd November 2022, K.W. Cheng, holotype, NTUPPMH 22-223 (Permanently preserved in a metabolically inactive state), ex-holotype NTUPPMCC 22-290.

Named after the serpentine soil from which the species was isolated.

Sexual morph undetermined. Asexual morph Conidia were observed on WA. Conidiophores solitary, hyaline, straight to slightly flexuous, smooth-walled, arising from hyphal ropes or vegetative hyphae. Phialides subulate, hyaline, wide at the base, with, 23–32 µm long. Schizophialides not observed. Conidia unicellular, cylindrical with rounded ends, hyaline, smooth-walled, 1-celled, few with inconspicuous 1 to 2 guttules on the end(s), sometimes aggregated in clusters forming a slimy head, 3.2–5.5 µm × 1.2–1.8 µm (x̄ = 4.3 × 1.5 µm, L/W ratio = 2.92, n = 30). Adelophialides observed, 3.6–8.8 µm long and sporulated obvious guttules and larger conidia, 3.8–7.0 µm × 1.6–2.5 µm (x̄ = 5.3 × 2.0 µm, L/W ratio = 2.73, n = 30).

Colony exhibit slow growth, reaching 30 mm diam with flat, pale orange, slightly wrinkled in the center, slimy, and smooth margin. The reverse side of the colony displayed similar characteristics.

Sarocladium serpentinicola introduced in this study forms a distinct clade with moderately support (82%/0.91) based on multi-locus phylogenetic analysis (Fig. 27). Moreover, S. serpentinicola forms significant genetic divergence to its closer relatives, ex-type strain of S. pseudostrictum (CBS 137660) with 96.0% identity in the ITS region (460/474 bp, including 5 gaps) and 96.2% identity in the tef-1 gene (777/808 bp). It also exhibits notable divergence from S. formosanum, another novel species described in this study, with 91.3% identity in the rpb2 gene (648/710 bp) and 96.9% identity in the tef-1 gene (783/808 bp). S. serpentinicola NTUPPMCC 22-290 can be distinguished from its close relatives S. pseudostrictum and S. graminicola by the presence of adelophialides and the production of larger conidia from these structures (Fig. 28; Giraldo et al. 2015; Anjos et al. 2020).

Figure 28. 

Morphology of Sarocladium serpentinicola NTUPPMCC 22-290. A, B 14-days-old colony on PDA; C, D Conidiophores and phialides; E, F Adelophialides; G Conidia. Scale bars: 10 µm (C–G).

The genus Dimorphiseta was introduced to place D. terrestris, a strain originally isolated from soil habit in USA by Lombard and Crous (2016), and three species are recognized in MycoBank (Accession date: March 10, 2025). Conidiomata of these species are superficial, oval to elongate or irregular in outline, sporodochial, stromatic, cupulate, scattered or gregarious, and are covered by an olivaceous green mucoid layer. Three distinct types of setae are present: type I – hyaline, thin-walled, flexuous to circinate, verrucose, tapering to an obtuse apice; type II – hyaline, thick-walled, septate, smooth, tapering to a sharp apice; type III – hyaline, thin-walled, straight, terminating in an obtuse apex. Conidiophores are irregular, macronematous and smooth-walled. Conidiogenous cells are hyaline, cylindrical, phialidic, smooth, with conspicuous collarettes while conidia are hyaline, cylindrical, fusiform, smooth, aseptate, funnel-shaped mucoid apical appendage (Lombard et al. 2016; Liang et al. 2019). The species of Dimorphiseta have been reported from China, Taiwan, and USA occurring on soil and also as saprobes in plant species belonging to Poaceae and Cannabaceae families (Lombard et al. 2016; Liang et al. 2019; Tennakoon et al. 2021).

TAIWAN • Wanrung Township, Hualien County, 23°42'40.3"N, 121°24'48.2"E, serpentine soil in rice field, 2^nd November 2022, K.W Cheng, holotype, NTUPPMH 22-224 (Permanently preserved in a metabolically inactive state), ex-holotype NTUPPMCC 22-291.

Named after Formosa, the former name of Taiwan, where the type specimen was collected.

Sexual morph undetermined. Asexual morph No sporulation on PDA and MEA, conidiomata produced very few on carnation leaves and surface of WA. Conidiomata 260–460 µm diam, randomly scattered, superficial, sporodochial, stromatic, subglobose to irregular in outline, dark green to black, agglutinated slimy mass of conidia. Setae thick-walled, hyaline, smooth, septate, straight to slightly curved, tapering to sharp apices, 170–240 µm long, 4–6 µm wide at broadest part. Conidiophores unbranched, hyaline to green, smooth to lightly verrucose, arising from basal stroma. Conidiogenous cells phialidic, hyaline, cylindrical, smooth, with collarette at tip, 17.2–22.7 µm × 1.7–2.3 µm (x̄ = 20 × 1.9 µm, n = 25). Conidia aseptate, hyaline, fusiform, smooth, few with funnel-shaped apical appendage, 7.8–9.0 µm × 2.1–3 µm (x̄ = 8.4 × 2.6 µm, L/W ratio = 3.32, n = 50).

Colony reaching 60 mm diam with white, fluffy, cotton-like mycelium in center that gradually thinned toward the edges with a slightly irregular margin. A slight yellowish-green pigment diffused in PDA and the reverse side of the medium appeared canary yellow.

This study introduces Dimorphiseta formosana as a new species, described from a single strain obtained from serpentine soil. D. formosana forms a distinct clade with moderately high statistical support (68%/0.98) based on multi-locus phylogenetic analysis (Fig. 30). Furthermore, D. formosana exhibits significant genetic divergence from its closest relative, the ex-type strain of D. obtusa (CGMCC 3.19206), across four loci: ITS (491/516 bp, identities 95.2%, including 1 gap), cmdA (501/572 bp, identities 87.6%, including 12 gaps), rpb2 (608/721 bp, identities 84.3%), and tub2 (254/307 identities, 82.7%, including 1 gap). Furthermore, our new species can be differentiated from D. obtusa (CGMCC 3.19206) by its smaller conidia, measuring 8–9 µm × 2–3 µm compared to 9–11 µm × 2–4 µm as reported by Liang et al. (2019) (Fig. 29). Even though its conidiogenous cells and conidia closely resemble those of the ex-type strain of D. terrestris (CBS 127345), our species lacks any Type I setae (Lombard et al. 2016). Additionally, while both D. formosana and D. serpentinicola were isolated from serpentine environments, D. formosana demonstrated a faster growth rate on PDA and produced a more vibrant yellow on the reverse side of the culture.

Figure 29. 

Morphology of Dimorphiseta formosana NTUPPMCC 22-291. A, B 14-days-old colony on PDA; C Conidiomata; D Setae; E Conidiophores and conidiogenous cells; F Conidia (red arrow: funnel-shaped appendage). Scale bars: 0.2 mm (C); 50 µm (D); 10 µm (E, F).

Figure 30. 

Maximum likelihood (ML) phylogenetic tree based on a concatenated dataset of ITS, cmdA, rpb2, and tub2. In total, 22 strains representing 19 taxa were included in the concatenated dataset, with 2424 characters (ITS 569 bp, cmdA 709 bp, rpb2 721 bp, and tub2 425 bp) including alignment gaps. The tree was rooted with Inaequalispora prestonii CBS 175.73. MLB ≥ 70% and BPPs ≥ 0.95 were shown at each node; values lower than these thresholds are indicated by a hyphen (–). The scale bar indicates the number of estimated substitutions per site. The strains introduced in this study are in red and novel species are in bold. The ex-type strains are marked with ^T.

TAIWAN • Wanrung Township, Hualien County, 23°42'40.3"N, 121°24'48.2"E, serpentine soil in rice field, 2^nd November 2022, K.W Cheng, holotype, NTUPPMH 22-225 (Permanently preserved in a metabolically inactive state), ex-holotype NTUPPMCC 22-292.

Named for the serpentine soil from which the species was isolated.

Sexual morph undetermined. Asexual morph No sporulation on PDA and MEA, conidiomata produced on carnation leaves. Conidiomata 258–548 µm diam, 70–225 µm deep, randomly scattered, superficial, sporodochial, stromatic, globose to subglobose, smooth outline, dark green to black, agglutinated slimy, mucoid mass of conidia. Setae thick-walled, hyaline, smooth, septate, straight to slightly curved, tapering to sharp apices, 180–280 µm long, 5–7 µm wide at broadest part. Conidiophores unbranched, hyaline to green, smooth to lightly verrucose, arising from basal stroma. Conidiogenous cells phialidic, hyaline, cylindrical, smooth, with collarette at tip, 18.3–23.5 µm × 1.6–2.2 µm (x̄ = 21.0 × 1.9 µm, n = 25). Conidia aseptate, hyaline, fusiform, smooth, funnel-shaped apical appendage, 7.4–8.7 µm × 2.2–3.1 µm (x̄ = 8.1 × 2.7 µm, L/W ratio = 3.07, n = 50).

Colony reaching 38 mm diam with abundant white, cotton-like mycelium and slightly irregular margin. A mustard pigment developed, and the reverse side of the medium appeared pale yellow.

The new taxon D. serpentinicola proposed in the present study forms a distinct clade with strong statistical support (97/1.00) based on multi-locus phylogenetic analysis (Fig. 30). Moreover, D. serpentinicola exhibits significant genetic divergence from its closest relative, the ex-type strain of D. acuta (CGMCC 3.19208), with 90.7% identity in the cmdA gene (526/580 bp, including 11 gaps) and 93.8% identity in the rpb2 gene (676/721 bp). The colony color and texture on PDA were similar to D. acuta CGMCC 3.19208, but pigment diffusion into the medium was observed in PDA (Fig. 31; Liang et al. 2019). D. acuta was previous recorded in Taiwan, isolated from the dead leaves of Celtis formosana by (Tennakoon et al. 2021). However, our species exhibited smaller conidia (8.1 × 2.7 µm versus 10.5 × 2.5 µm) and longer setae (up to 280 µm versus 150 µm) compared to D. acuta (Tennakoon et al. 2021).

Figure 31. 

Morphology of Dimorphiseta serpentinicola NTUPPMCC 22-292. A, B 14-days-old colony on PDA; C Conidiomata; D Setae; E, F Conidiophores and conidiogenous cells; G, H Conidia (red arrow: funnel-shaped appendage). Scale bars: 0.5 mm (C); 50 µm (D); 20 µm (E); 10 µm (F, G); 5 µm (H).

The genus Pseudothielavia was initially proposed by Wang and Houbraken (2019), to place Coniothyrium terricola, which is initially isolated from soil habitat. In recent years several species were introduced in this genus and currently four species epithets are listed in MycoBank (Accession date: March 10, 2025) for Pseudothielavia. Ascomata of these species are solitary to aggregated, globose or subglobose, superficial or submerged. They are typically non-ostiolate, though some species develop an ostiole at maturity. Peridium is brown, composed of textura epidermoidea, and may appear semi-translucent or translucent. Asci are clavate to pyriform, eight-spored and evanescent. Ascospores are 1-celled, olivaceous brown at maturity, smooth-walled, fusiform in shape and possess an apical, oblique or lateral germ pore (Wang et al. 2019). Species reported for Pseudothielavia are widely distributed and have been reported from Chile, China, Egypt, Japan, Papua New Guinea, and USA mainly from soil habitats (Wang et al. 2019; Zhang et al. 2021; Noguchi et al. 2022; Hussien et al. 2023).

Sexual morph Cleistothecia 105–145 µm diam, non-ostiolate, globose, glabrous, black when mature, solitary to aggregated, mostly superficial, some submerged in PDA, aerial mycelium covered. Peridium brown, semi-translucent, membranous, textura epidermoidea. Asci subglobose to pyriform, hyaline when immature, eight-spored, 23.7–27.0 µm × 20.5–23.5 µm (x̄ = 25.5 × 22.5 µm, L/W ratio = 1.13, n = 10). Ascospores 1 celled, olivaceous brown when mature, subglobose to ellipsoidal, some smooth, apical germ pore, 9.3–11.7 µm × 6.7–9.0 µm (x̄ = 10.5 × 7.6 µm, L/W ratio = 1.39, n = 20). Asexual morph undetermined.

Colony reaching 50 mm diam with thick white aerial mycelium, fluffy, edge irregularly, wavy margin, and similar to reverse side of the colony.

TAIWAN • Guanshan Township, Taitung County, 23°02'12.8"N, 121°11'22.0"E, serpentine soil in rice field, 2^nd November 2022, K.W Cheng, living culture NTUPPMCC 22-293 and NTUPPMCC 22-294.

Two strains (NTUPPMCC 22-293 and NTUPPMCC 22-294) isolated in this study clustered within the clade containing ex-type strains, along with other representative strains of Pseudothielavia arxii and Pse. terricola, with strong statistical support (100%/1.00) (Fig. 33). Although both Pse. arxii and Pse. terricola exhibited no clear phylogenetic variation in our tree or in previous studies, they can be distinguished by differences in ascospore morphology (Wang et al. 2019). The morphology of our strain (NTUPPMCC 22-294) exhibited an apical germ pore, similar to that of Pse. terricola (CBS 165.88) (Fig. 32). According to its original description (Wang et al. 2019; Noguchi et al. 2022), Pse. arxii lacks an apical germ pore and instead possesses an oblique to lateral germ pore. Therefore, based solely on morphological similarity, we identified our strain as Pse. terricola. However, further studies are required to determine whether Pse. arxii and Pse. terricola represent two distinct species or a single species. This study represents the first discovery of a Pseudothielavia species in Taiwan.

Figure 32. 

Morphology of Pseudothielavia terricola NTUPPMCC 22-294. A, B 14-days-old colony on PDA; C Ascomata; D Squashed ascomata; E Immature ascus; F Ascospores. Scale bars: 1 mm (C); 50 µm (D); 20 µm (E, F).

Figure 33. 

Maximum likelihood (ML) phylogenetic tree based on a concatenated dataset of ITS, LSU, rpb2, and tub2. In total, 26 strains representing 21 taxa were included in the concatenated dataset, with 2315 characters (ITS 531 bp, LSU 556 bp, rpb2 809 bp, and tub2 419 bp) including alignment gaps. The tree was rooted with Triangularia longicaudata CBS 252.57. MLB ≥ 70% and BPPs ≥ 0.95 were shown at each node; values lower than these thresholds are indicated by a hyphen (–). The scale bar indicates the number of estimated substitutions per site. The strains introduced in this study are in red and novel species are in bold. The ex-type strains are marked with ^T.

The genus Pseudorhypophila was proposed accommodate four Zopfiella species namely, Zopfiella mangenotii, Z. marina, Z. pilifera, and Z. submersa, which form a well-supported monophyletic clade within the family Navicularisporaceae in Harms et al. (2021). At present, four species are recognized in MycoBank (Accession date: March 10, 2025). Species in this genus are characterized in their sexual stage by immersed to erumpent ascomata that are non-ostiolate or ostiolate, and globose to subglobose or ovate to pyriform in shape. Asci are clavate to cylindrical, stipitate, and contain 4–8 spores, with a small apical ring that may sometimes be indistinct. Ascospores are biseriate and two-celled, often enclosed in gelatinous sheaths. They are hyaline and thin-walled. The upper cell is olivaceous brown to dark brown, usually narrowly conical with an acuminate apex and a rounded base; occasionally ovoid to limoniform, bearing an apical or subapical germ pore, and sometimes a distinct apical appendage. The lower cell remains hyaline, though it may occasionally appear pale olivaceous brown, pale brown, or even dark brown. It is straight and cylindrical, but may also be curved, hemispherical, or initially broadly obconical, later becoming flattened at the apex (Guarro et al. 1997; Harms et al. 2021). In the asexual stage Pseudorhypophila species produce holoblastic hyaline conidia that are spherical to subspherical, or ovate to elongate, smooth-walled, sessile, borne singly along the vegetative hyphae (Harms et al. 2021; Liu et al. 2025). Pseudorhypophila has been reported from Egypt, France, Iraq, Japan, South Korea and Taiwan, occurring on substrates such as freshwater, plant debris, soil, and mud (Guarro et al. 1997; Chang et al. 2010; Marin-Felix et al. 2020; Hussien et al. 2023; Liu et al. 2025).

TAIWAN • Guanshan Township, Taitung County, 23°02'14.8"N, 121°11'22.6"E, serpentine soil in rice field, 3^rd November 2022, K.W. Cheng, holotype, NTUPPMH 22-226 (Permanently preserved in a metabolically inactive state), ex-holotype NTUPPMCC 22-297, ex-isotype NTUPPMCC 22-295, 296, 298 to 300.

Named after Formosa, the former name of Taiwan, where the type specimen was collected.

Sexual morph Ascomata 342–504 µm diam, non-ostiolate, globose, dirty gray when immature, black when mature, submerged in PDA. Peridium multi-layered, brown, translucent, membranous, angular cells. Asci clavate to cylindrical, hyaline when immature, eight-spored, 74–111 µm × 14–21 µm (x̄ = 90.9 × 17.8 µm, L/W ratio = 5.13, n = 20). Ascospores two-celled; upper cell ellipsoidal to slightly fusiform, smooth, brown, multiple guttules, subapical germ pore, 18.3–24.6 µm × 8.8–12.5 µm (x̄ = 21.3 × 11.0 µm, L/W ratio = 1.95, n = 50), lower cell cylindrical with slightly tapering or rounded end, hyaline to pale brown, thin-walled, 4.0–8.0 µm × 3.1–5.8 µm (x̄ = 5.8 × 4.3 µm, L/W ratio = 1.36, n = 50). Asexual morph undetermined.

Colony exhibit rapid growth, reaching 80 mm diam with flat, sparse aerial mycelium, white, surface and margins slight smooth. The reverse exhibited blackish-gray center, with a gradient radiating outward into lighter gray tones.

In the present study, six Pseudorhypophila strains (NTUPPMCC 22-295 to 300) formed a distinct clade with a strong statistical support (100%/1.00), clearly separating from known Pseudorhypophila species in the multi-locus phylogenetic analysis (Fig. 35). Furthermore, the ex-type strain of Pseudorhypophila formosana (NTUPPMCC 22-297) exhibits significant genetic divergence from its closest relatives, the ex-type strains of P. mangenotii (CBS 419.67) and P. poae (CMML 20-36), with 94.0% (936/996 bp) and 94.2% (938/996 bp) identity, respectively, in the rpb2 gene. In line with earlier research on P. marina and P. pilifera, our isolate produces ascomata lacking ostioles and bearing 2-celled ascospores, a distinctive trait of the Pseudorhypophila (Harms et al. 2021). However, P. formosana NTUPPMCC 22-297 is distinguished by its lower cell lengths, which are noticeably smaller than those of the type species, P. marina CBS 698.96 (4–8 µm × 3–6 µm versus 6–13 µm × 3–5 µm) (Fig. 34; Guarro et al. 1997). Moreover, P. poae has been recorded only in its asexual morph, which was not observed in our strains (NTUPPMCC 22-295 to 300). Notably, the other representative strain of P. marina (Zopfiella marina CBS 155.77) was previously reported from Taiwan. However, it also differs from P. formosana NTUPPMCC 22-297 in morphology, phylogeny and habitat (marine mud versus terrestrial serpentine soil) (Overy et al. 2014; Harms et al. 2021).

Figure 34. 

Morphology of Pseudorhypophila formosana NTUPPMCC 22-297. A, B 14-days-old colony on PDA; C Ascomata; D Immature ascomata; E Squashed ascomata; F, G Immature ascus; H, I Ascus; J Ascospores; K, L Ascospores (red arrows: subapical germ pores). Scale bars: 0.5 mm (C); 100 µm (E); 20 µm (D, F–I); 10 µm (J); 5 µm (K–L).

Figure 35. 

Maximum likelihood (ML) phylogenetic tree based on a concatenated dataset of ITS, LSU, and rpb2. In total, 23 strains representing 16 taxa were included in the concatenated dataset, with 2444 characters (ITS 569 bp, LSU 869 bp, and rpb2 1006 bp) including alignment gaps. The tree was rooted with Corylomyces selenosporus CBS 113930. MLB ≥ 70% and BPPs ≥ 0.95 were shown at each node; values lower than these thresholds are indicated by a hyphen (–). The scale bar indicates the number of estimated substitutions per site. The strains introduced in this study are in red and novel species are in bold. The ex-type strains are marked with ^T.

The genus Phialoparvum was introduced by Giraldo and Crous (2019) to place Phialoparvum bifurcatum, which was isolated from soil habitat in Belgium. To date, three species are recognized in MycoBank (Accession date: March 10, 2025) for Phialoparvum. The genus was introduced solely based on the asexual morph and characterized by its erect, originating directly from vegetative hyphae or hyphal ropes, which can be either unbranched or poorly branched conidiophores (Giraldo and Crous 2019). Conidiogenous cell of this genus is enteroblastic, hyaline, mono-, poly-, and adelophialides, subulate to ampulliform while forming conspicuous collarette. Conidia are cylindrical, hyaline, unicellular, smooth-walled, and aggregated in slimy heads (Giraldo et al. 2019).

TAIWAN • Guanshan Township, Taitung County, 23°02'14.8"N, 121°11'22.6"E, serpentine soil in rice field, 3^rd November 2022, K.W. Cheng, holotype, NTUPPMH 227 (Permanently preserved in a metabolically inactive state), ex-holotype NTUPPMCC 22-301.

Named after Formosa, the former name of Taiwan, where the type specimen was collected.

Sexual morph undetermined. Asexual morph Conidia were observed on WA. Conidiophores solitary, hyaline, straight to slightly flexuous, arising from hyphal ropes or vegetative hyphae. Phialides subulate to ampulliform, hyaline, terminal or lateral, with conspicuous periclinal thickening and cylindrical collarette, 4–18 µm long. Mono-phialides or adelophialides predominant, few poly-phialides with two conidiogenous loci. Conidia cylindrical, hyaline, smooth, thick-walled, 1-celled, with 1 to 2 guttules, sometimes aggregated in clusters forming a slimy head, 3.6–4.6 µm × 1.7–2.4 µm (x̄ = 4.2 × 2.1 µm, L/W ratio = 2.04, n = 50).

Colony exhibit slow growth, reaching 30 mm diam with flat, creamy white, and velvety to powdery at the center, gradually thinning toward the edges with a smooth margin. The reverse side of the colony displayed similar characteristics.

In our multi-locus phylogenetic assessment, Phialoparvum formosanum forms a distinct branch with low statistical support, sister to the clade containing the ex-type strain of Ph. bifurcatum (CBS 299.70B). Despite the weak nodal support, these taxa exhibit substantial genetic divergence across three loci: ITS (440/455 bp, identities 96.7%, including 7 gaps), rpb2 (259/279 bp, identities 92.8%), and tef-1 (761/787 bp, identities 96.7%) (Fig. 37 and Suppl. material 2: figs S3–S5). Ph. formosanum NTUPPMCC 22-301 shares typical characteristics of the genus Phialoparvum, including hyaline, solitary, arising from hyphal ropes or vegetative hyphae of conidiophores and subulate to ampulliform phialides. However, the conidia of Ph. formosanum NTUPPMCC 22-301 are broader than the type strain of Ph. bifurcatum CBS 299.70B (3.6–4.6 µm × 1.7–2.4 µm versus 2.8–4.4 µm × 1.2–1.8 µm) (Fig. 36; Giraldo and Crous 2019). Additionally, Ph. formosanum exhibits prominent guttules in its conidia, a feature that differentiates it from the other three Phialoparvum species (Fig. 36; Giraldo and Crous 2019; Giraldo et al. 2019).

Figure 36. 

Morphology of Phialoparvum formosanum NTUPPMCC 22-301. A, B 14-days-old colony on PDA; C–E Conidiophores, phialides, and conidiogenous cells; F Conidia. Scale bars: 10 µm (C–F).

Figure 37. 

Maximum likelihood (ML) phylogenetic tree based on a concatenated dataset of ITS, LSU, rpb2, and tef-1. In total, 26 strains representing 19 taxa were included in the concatenated dataset, with 2810 characters (ITS 477 bp, LSU 798 bp, rpb2 748 bp, and tef-1 787 bp) including alignment gaps. The tree was rooted with Sodiomyces alcalophilus CBS 114.92. MLB ≥ 70% and BPPs ≥ 0.95 were shown at each node; values lower than these thresholds are indicated by a hyphen (–). The scale bar indicates the number of estimated substitutions per site. The strains introduced in this study are in red and novel species are in bold. The ex-type strains are marked with ^T.