Abstract
The classification of taxa belonging to the Sordariales has been problematic over the years. With the beginning of the DNA era, ascospore morphology, which was the main criterium for the delimitation of taxa in the Sordariales, was demonstrated to not be useful for inferring taxonomic relationships especially at the genus level. In the past decades, the combination of both morphological and molecular data allowed the reclassification of these taxa. Recently, a study of some often overlooked Diaporthomycetidae and Sordariomycetidae included a new taxonomic classification for members of the Sordariales, many of which were based on nomenclatural errors or which lacked sufficient data to support their hypotheses. The authors did not contribute any new DNA sequences, but instead relied on datasets generated by previous authors in their published phylogenetic studies. Surprisingly, different results were obtained contradicting these previous studies and, in an act of taxonomic vandalism, five new families were introduced without performing further molecular analyses to verify the incongruencies with these previous studies. Three of these new families, which we consider doubtful, are Bombardiaceae, Lasiosphaeridaceae and Zygospermellaceae. The family Strattoniaceae is here considered superfluous since it was introduced to accommodate only a single genus and delimited based on a species that is not the type species of Strattonia. The Neoschizotheciaceae was erected based on the new genus Neoschizothecium, which was introduced to accommodate members of Schizothecium since Huang et al. (2021) considered Schizothecium as a synonym of Podospora after misinterpreting their type species as the same. However, Schizothecium and Podospora have been two independent genera based on two different type species for half a century, making Neoschizothecium and Neoschizotheciaceae superfluous. Moreover, they proposed 32 new combinations, 16 of which are now superfluous or doubtful. Most of these taxonomic errors could have been avoided if a proper literature review had been performed. Two examples are the new superfluous combinations of Triangularia tarvisina and Cladorrhinum olerum, because the former is considered conspecific with Triangularia setosa, and the latter conspecific with Cladorrhinum foecundissimum, the anamorph of Arnium olerum. The focus of the current review is to provide a scientifically responsible alternative to the erroneous novelties proposed at the family, genus and species level in the recent classification of Sordariales.
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Introduction
The order Sordariales is one of the most diverse groups in the Sordariomycetes and the classification of their members based solely on morphology has been problematic (Hawksworth and Eriksson 1986; Miller and Huhndorf 2004a, 2005; Huhndorf et al. 2004; Kruys et al. 2015). The taxonomic classification of taxa belonging to this order was traditionally based on ascospore morphology; however, Miller and Huhndorf (2005) demonstrated that this character is extremely homoplastic and not useful for inferring taxonomic relationships. Instead, the ascomatal wall morphology appears to be more phylogenetically informative, even though it has its limitation since not all taxa exhibit distinctive features in their ascomatal walls, and/or similar ascomatal wall characteristics are found in different monophyletic lineages.
For nearly two decades, extensive molecular studies have been combined with morphological data to delimit sordarialean taxa at the family, genus and species level (Miller and Huhndorf 2004a; Cai et al. 2005; Kruys et al. 2015; Wang et al. 2019a; Marin-Felix et al. 2020). Historically, the Sordariales has contained 7 to 14 families, depending on the authors’ concepts (Hawksworth and Eriksson 1986; Eriksson et al. 2001). Huhndorf et al. (2004) restricted the order to 3 families, i.e. Chaetomiaceae, Lasiosphaeriaceae and Sordariaceae, the first two of which were considered polyphyletic based on molecular data. The Chaetomiaceae has been extensively studied in recent years based on a polyphasic approach combining morphological and molecular data, resulting in its delimitation as a monophyletic lineage (Wang et al. 2019a, b). However, the polyphyly of Lasiosphaeriaceae, which was the largest family of the order, remained problematic until it was recently partly resolved (Marin-Felix et al. 2020). Kruys et al. (2015) demonstrated the separation of the family into four different clades. Subsequently, Wang et al. (2019a) introduced the new family Podosporaceae to accommodate taxa belonging to clade IV in Kruys et al. (2015). Marin-Felix et al. (2020) delimited Lasiosphaeriaceae to clade III, which contained the type genus Lasiosphaeria. Moreover, the new families Diplogelasinosporaceae, Naviculisporaceae and Schizotheciaceae were introduced to accommodate three monophyletic lineages containing taxa resembling those in the Lasiosphaeriaceae. Once again, the morphological characters used to delimit these families turned out to be homoplastic and appeared independently in multiple lineages. Other lasiosphaeriaceous taxa were nested in an unsupported lineage (Lasiosphaeriaceae s. lat. I, Fig. 1), and therefore a new family was not introduced for this clade. Finally, another monophyletic lineage with two genera was shown as an unsupported sister group to Schizotheciaceae (Lasiosphaeriaceae s. lat. II, Fig. 1). However, a new family was not introduced until further studies including additional taxa and molecular data could be performed. Figure 1 shows the phylogenetic tree obtained from the study performed by Marin-Felix et al. (2020).
The genera belonging to this order have also been taxonomically challenging to delineate over the years. For example, the genera Gelasinospora and Neurospora, both in the Sordariaceae, were established based on different patterns of ascospore ornamentation. García et al. (2004) demonstrated that this character was not phylogenetically informative and synonymized Gelasinospora under Neurospora. This observation agreed with Miller and Huhndorf (2005), who found that ascospore morphology was a homoplastic character throughout the order. The largest genera in the Chaetomiaceae have also been recently refined, i.e. Chaetomium, Humicola and Thielavia, resulting in the introduction of 17 new genera and more than 70 new combinations to accommodate taxa not included in the molecular-based monophyletic lineages of these recircumscribed genera (Wang et al. 2016a, 2019a, b). Genera traditionally placed in Lasiosphaeriaceae are currently being studied. For example, Wang et al. (2019a) delimitated Cladorrhinum, Podospora and Triangularia, whereas Marin-Felix et al. (2020) established 5 new genera, i.e. Areotheca, Lundqvistomyces, Pseudoechria, Pseudoschizothecium and Rhypophila. These taxonomic changes were done to accommodate taxa previously placed in Cercophora, Podospora and Triangularia based on morphology, but that no longer occurred in the more narrowly defined, DNA-based monophyletic lineages representing these genera.
Recently, Huang et al. (2021) performed a phylogenetic study based on ITS, LSU, RPB2 and TUB2 sequences already available in GenBank, without generating a single new sequence. As a result, they introduced 5 new families, 1 new genus and 32 new combinations in the order Sordariales. However, most of these taxonomic novelties are based on errors of interpretation or lack sufficient data for their creation (Table 1). In order to compare the contradictory results between the phylogenetic study of Huang et al. (2021) and previous studies (Kruys et al. 2015; Marin-Felix et al. 2020), we tried to reanalyze the original molecular alignments generated by Huang et al. (2021). However, these alignments are not available in TreeBase even though they stated in their publication that final alignments and trees were deposited in TreeBase. Therefore, we had to download all sequences from GenBank to perform a phylogenetic analysis that included all sequences previously used in Marin-Felix et al. (2020) and Huang et al. (2021). No sequences in Chaetomiaceae were included since no novelties were proposed in this family (Table 2). The maximum likelihood (ML) and Bayesian inference (BI) analyses including the four loci were performed as described by Harms et al. (2021). The lengths of the individual alignments used in the combined dataset were 556 bp (ITS), 916 bp (LSU), 978 bp (RPB2) and 618 bp (TUB2), and the final combined alignment was 3068 bp. A poorly aligned ambiguous region was manually deleted from the ITS1 region. Figure 2 shows the most likely tree obtained from the RAxML analysis of the combined dataset generated in our study. It is identical in the topology of the 95% majority-rule consensus tree generated by the Bayesian analysis. It is unfortunate that Huang et al. (2021) did not indicate the GenBank accession numbers of the sequences they used to produce their trees, making it very difficult for the scientific community to reproduce their results. It should have been mandatory to indicate which sequences were incorporated in their phylogenetic study, as well as to cite the underlying papers giving proper attribution to the authors that generated those data, as recommended in Aime et al. (2020), a recent ICTF-sponsored paper on best practices in taxonomy. Surprisingly, the second author of Huang et al. (2021) is also a co-author of the Aime et al. (2020) paper, yet he does not follow his own recommendation.
New families superfluously introduced or without sufficient evidence
The family Schizotheciaceae was recently introduced by Marin-Felix et al. (2020) to accommodate lasiosphaeriaceous taxa occurring in a well-supported monophyletic lineage phylogenetically distant from both the Podosporaceae and the clade containing the type genus Lasiosphaeria. However, Huang et al. (2021) erroneously changed its name to Neoschizotheciaceae based on taxonomic errors by Wang et al. (2019a). Both papers incorrectly assumed that the genera Schizothecium and Podospora shared the same type species, and thus, should be synonymized. Therefore, the new genus Neoschizothecium was introduced with N. curvisporum as its type species to accommodate species of Schizothecium outside the Podosporaceae. Huang et al. (2021) designated Neoschizothecium as type genus of their new family Neoschizotheciaceae.
The complex nomenclatural histories surrounding the type species of Podospora and Schizothecium have been discussed in detail (Lundqvist 1972; Ament-Velásquez et al. 2020; Vogan et al. 2021). Briefly, two distinct type specimens representing two distinct type species exist for each genus: the conserved non-original type specimen of Podospora fimiseda (Ces. & De Not.) Niessl. (in Hedwigia 22: 156. Oct 1883) and the lectotype illustration of Schizothecium fimicola Corda (in Icon. Fung. 2: 29, tab. 13, fig. 105, Jul 1838). This segregation, which was based on morphological data and discussed by Lundqvist (1972), was later supported by molecular data (Cai et al. 2005). Wang et al. (2019a) overlooked the conserved type of Podospora (i.e. Sordaria fimiseda Ces. & De Not.) and incorrectly cited S. fimicola Corda as type species. To further complicate matters, Wang et al. (2019a) designated an epitype specimen (CBS H-24048) for S. fimicola that was induced to produce fertile ascomata in culture (CBS 482.64), but this epitype represents P. fimiseda, not S. fimicola! We have examined the ex-epitype culture (CBS 482.64) and could not reproduce the fruiting of ascomata in culture. The epitype specimen was also examined, but no ascomata were found to study their morphology in detail, despite images of mature ascomata fruiting in culture provided in Wang et al. (2019a). According to the pictures of the epitype shown by Wang et al. (2019a), this specimen produces hyphal-like ascomatal hairs surrounding the entire ascoma, which match P. fimiseda (Miller 2003). Schizothecium fimicola has swollen agglutinated ascomatal hairs only in the upper part of the ascomata. Thus, the type species of Schizothecium should be conserved as S. fimicola (typ. cons. pending). The ascomal wall of CBS 482.64 needs to be studied to verify that it is pseudo-bombardioid and matches the description of P. fimiseda (Miller 2003) and, therefore, it is a suitable epitype for this later species. If the conservation proposal to change the type species of Podospora from P. fimiseda to P. anserina (Vogan et al. 2021) is accepted, this would also bring additional resolution to the complicated and often confused nomenclatural history of these two genera. Since Podospora and Schizothecium are clearly not synonyms as Wang et al. (2019a) and Huang et al. (2021) believed, there was no reason to create a new family (i.e. Neoschizotheciaceae) for Schizotheciaceae. Thus, Neoschizotheciaceae is nomenclaturally illegitimate (Art. 14.3, Shenzhen Code) and a superfluous synonym of Schizotheciaceae.
It is worthwhile to mention that one should always attempt to make decisions that lead to as few taxonomic name changes and reduce the possibility of publishing taxonomically superfluous names, as recommended in the recent guidelines for publishing new fungal species or names, version 3.0 (Aime et al. 2020). This is especially important in this group of fungi, in which many names are not represented by DNA sequences of type material and many new combinations are possible. Therefore, the proposal to introduce a new genus with numerous subsequent new combinations for an established lineage should have never been accepted and was easily avoidable if a review of the literature was performed.
The new family Strattoniaceae was erected to accommodate the genus Strattonia. Surprisingly, the genus was redefined without the study of any material of the type species (St. tetraspora), but based only on the already available sequences of the type strain of another species, St. oblecythiformis. The redefinition was made only on morphological characters even though it has already been clearly demonstrated that taxonomists must be careful proposing any taxonomic reclassification of members of the Sordariales and that a polyphasic approach based on both morphological and molecular data is required (Miller and Huhndorf 2004a; Kruys et al. 2015; Marin-Felix et al. 2020). It is of note that no cultures of St. tetraspora are available in any recognized culture collection. Therefore, it is of upmost importance to recollect this species and include it in phylogenetic analyses to confirm the monophyly of Strattonia. Huang et al. (2021) argued that the characteristics of Strattonia should be reduced to those species producing ascospores with an upper cell surrounded by a gelatinous sheath. On the other hand, taxa that have no sheath have been demonstrated to belong to different genera, i.e. Jugulospora and Lundqvistomyces (Marin-Felix et al. 2020). Therefore, the presence or absence of an ascospore sheath is polyphyletic and one cannot assume that all species with ascospores surrounded by a sheath are going to belong to the same monophyletic lineage. In fact, other species characterized by ascospores surrounded by a gelatinous sheath are placed in different genera, such as Echria (Schizotheciaceae), Fimetariella (Lasiosphaeriaceae s. lato) and Sordaria (Sordariaceae). This family is erected based on a clade containing only two species, S. oblecythiformis and the new combination S. petrogale, but both species only contain sequences from the internal transcribed spacer region (ITS) and the nuclear rDNA large subunit (LSU) from the study of Vu et al. (2019). For these reasons, we reject the family Strattoniaceae until additional taxa, including the type species, and additional genes (i.e. RPB2 and TUB2) have been studied.
The families Lasiosphaeridaceae and Zygospermellaceae, erected for only one and two genera, respectively, are also points of contention since they were proposed based on limited taxon sampling and poor taxonomic practices. In the recent phylogenetic studies from Kruys et al. (2015) and Marin-Felix et al. (2020), both clades now considered independent families by Huang et al. (2021) were clustering together in a well-supported clade. Huang et al. (2021) prematurely introduced both families since they formed two independent lineages in their phylogenetic study. However, both families are included in the Schizotheciaceae clade in our Bayesian phylogenetic study (0.97 pp) (Fig. 2). More taxa and sequences should be incorporated in further phylogenetic analyses to verify if the Lasiosphaeridaceae and Zygospermellaceae are two independent lineages or belong to the Schizotheciaceae. For these reasons, we reject these families until more data can be analysed and we refer to both lineages as Lasiosphaeriaceae s. lato.
In our phylogenetic study, the only family not supported is Lasiosphaeriaceae s. str. However, the conflicts may be caused by the high number of taxa in which only the ITS and LSU sequences are available, which most likely influences the backbone relationships and support for these phylogenetic relationships resulting in misleading higher-level classifications. Although most strains included in Huang et al. (2021) are available in the CBS collection, and therefore additional loci could have been sequenced, they chose not to generate these critical sequence data for their phylogenetic analyses.
Finally, the family Bombardiaceae was introduced by Huang et al. (2021), even though the ML bootstrap support was only 76% and there was no Bayesian inference support for this clade. Huang et al. (2021) explained that Marin-Felix et al. (2020) discussed the low support of this lineage, and for that reason no family was introduced to accommodate it. Nonetheless, they considered this lineage to be well-supported in their phylogenetic study, and therefore the new family Bombardiaceae was introduced to represent it. In our phylogenetic study (Fig. 2), which included the same sequences that Huang et al. (2021) used, the clade representing this family is not supported (42% bs/0.89 pp), so we do not accept the Bombardiaceae as a justifiable family.
We take this opportunity to clarify that most of the outgroups used in Huang et al. (2021) do not belong to the family Microascales as they erroneously indicated, but rather to the Coronophorales (syn. Melanosporales) as in the case of all the Microthecium spp. included, as well as Thielavia basicola.
New genera superfluously introduced or redefined based on poor taxonomic practice
As mentioned above, Neoschizothecium is a superfluous genus based on misinterpretation of the type species of Podospora and Schizothecium so it is nomenclaturally illegitimate (Art. 14.3, Shenzhen Code) and thus, a superfluous synonym under Schizothecium. The delimitation of Strattonia based on a single species is a poor taxonomic decision since the type species of the genus was not included in the study of Huang et al. (2021). Finally, the delimitation of Cercophora is also based on poor taxonomic practice since Huang et al. (2021) chose a dubious candidate to represent the type species of C. mirabilis in their analyses but thankfully, they did not designate an epitype. It is impossible to confirm the morphological identification of this strain (CBS 120402) because it does not sporulate in culture as mentioned by Marin-Felix et al. (2020). Therefore, it is not a suitable representative of the type species of Cercophora and a suitable epitype must be studied and designated before this genus can be properly delimited. The placement of Cercophora spp. in different lineages and families support the necessity of a detailed study of this genus and the careful designation of an epitype for the type species in order to determine the proper taxonomic placement of Cercophora within the order.
New combinations superfluously introduced or failing to follow good taxonomic practice
The new combination of Cladorrhinum olerum proposed to accommodate Arnium olerum is superfluous because Marin-Felix et al. (2020) already synonymized this latter name under Cl. foecundissimum. The nucleotide similarity between both species is 99.81% for ITS, 100% for LSU, 98.60% for RPB2 and 100% for TUB2, suggesting that these represent the asexual and sexual morphs of the same taxon.
The new combination T. tarvisina is superfluous since P. tarvisina has been considered a synonym of T. setosa for 50 years based on their morphological similarity (Lundqvist 1972). This is corroborated based on the high nucleotide similarity greater than 99.5% of the four loci (ITS, LSU, RPB2 and TUB2) between both species according to a BLAST comparison. Therefore, this new combination was made in error due to the failure of a proper literature review by Huang et al. (2021). Likewise, the new combination T. praecox is also superfluous since this species shows morphological and molecular similarity also with T. setosa, and therefore P. praecox is here considered a synonym to this later species. The description of T. setosa is here emended to incorporate the sizes observed in P. praecox when it was introduced, which are similar to T. setosa except for the ascus dimensions (up to 190 μm wide in P. praecox vs. up to 60 μm in T. setosa) (Cailleux 1969; Lundqvist 1972; Wang et al. 2019a).
Triangularia setosa (G. Winter) X. Wei Wang & Houbraken, Stud. Mycol. 93: 243. 2019. emend. Y. Marin & A.N. Mill.
MB829894
Basionym: Sordaria setosa G. Winter, Abh. Naturf. Ges. Halle 13: 97. 1873.
Synonyms: Philocopra setosa (G. Winter) Sacc., Syll. Fung. 1: 249. 1882.
Podospora setosa (G. Winter) Niessl, Hedwigia 22: 156. 1883.
Pleurage setosa (G. Winter) Kuntze, Revis. Gen. Pl. 3: 505. 1898.
Cladochaete setosa (G. Winter) Sacc., Ann. Mycol. 10: 318. 1912.
Philocopra setosa subsp. tarvisina Sacc., Syll. Fung. (Abellini) 1: 250. 1882.
Philocopra setosa var. tarvisina (Sacc.) Traverso, Fl. Ital. Crypt. (Florence) 1: 437. 1907.
Philocopra tarvisina (Sacc.) J.H. Mirza & Cain, Can. J. Bot. 47: 2041. 1970.
Podospora tarvisina (Sacc.) J.H. Mirza & Cain, Can. J. Bot. 47: 2041. 1970.
Triangularia tarvisina (Sacc.) S.K. Huang & K.D. Hyde, Fungal Divers. 111: 515. 2021.
Podospora praecox Cailleux, Cahiers de La Maboké 7: 102. 1969.
Triangularia praecox (Cailleux) S.K. Huang & K.D. Hyde, Fungal Divers. 111: 515. 2021.
Ascomata superficial, mouse grey in reflected light, solitary, ovoid to ampulliform with a short, black beak, ostiolate, 230–900 μm high, 185–800 μm diam; ascomatal wall brown, opaque, of textura intricata or epidermoidea in surface view; ascomatal hairs arising mainly around the lower half, hyphal-like, erect or flexuous, brown, 1.5–3 μm diam near base. Asci fasciculate, fusiform or elongated fusiform, 170–430 × 25–60(–190) μm, without a conspicuous apical ring, stipitate, stipe 21.5–62 μm long, containing numerous irregularly- and densely-arranged ascospores, evanescent. Ascospores at first one-celled, hyaline, becoming transversely septate and two-celled; upper cell olivaceous brown to brown, ellipsoidal to broadly fusiform, equilateral, with an apical germ pore, (15–)17–21.5(–22) × (9–)10.5–13 μm; lower cell hyaline, clavate to cylindrical, 8–12 × 2–3 μm; apical and basal mucilaginous appendages mostly present, up to 120 μm long. Asexual morph not observed (adapted from Lundqvist 1972 and Wang et al. 2019a).
Huang et al. (2021) proposed the new combination Jugulospora minor to accommodate Strattonia minor. Even though we consider the transference of this species to Jugulospora necessary, Huang et al. (2021) did not demonstrate whether it is an independent species or if it should be synonymized with J. rotula as happened with Apiosordaria globosa, A. hispanica and Rhexosporium terrestre (Marin-Felix et al. 2020). Strattonia minor is similar to J. rotula, differing only by the size of the upper cell of the ascospores and the width of the asci (Lundqvist 1972; Marin-Felix et al. 2020). In our phylogenetic study (Fig. 2), the type strain of this species occurred in the moderately well-supported clade (82% bs/0.98 pp) representing J. rotula. Therefore, J. minor is here considered a synonym of J. rotula, whose description is here emended to incorporate the new sizes of asci and ascospores.
Jugulospora rotula (Cooke) N. Lundq. emend. Y. Marin & A.N. Mill.
MB315972
Basionym: Sphaeria rotula Cooke, Handb. British Fungi 2: no. 2598. 1871.
Synonyms: Strattonia minor N. Lundq., Symb. Bot. Upsal. 20: 271. 1972.
Jugulospora minor (N. Lundq.) S.K. Huang & K.D. Hyde, Fungal Divers. 111: 95. 2021.
Rhexosporium terrestre Udagawa & Furuya, Trans. Mycol. Soc. Japan 18: 303. 1977.
Apiosordaria globosa Dania García, Stchigel & Guarro, Mycologia 95: 137. 2003.
Apiosordaria hispanica Dania García, Stchigel & Guarro, Mycologia 95: 134. 2003.
Ascomata ostiolate, superficial or immersed, scattered to aggregated, pale brown to brown, pyriform, 350–770 × 200–540 μm, covered with pale brown, septate hyphal-like hairs, 1–5 μm diam; neck brown to dark brown, cylindrical to conical, papillate, 80–280 μm long, 90–250 μm wide; ascomatal wall membranaceous, semi-transparent, brownish-orange to brown, 3–9-layered, 15–45 μm thick; outer layers textura angularis and textura intricata; inner layers textura epidermoidea. Paraphyses and periphyses filiform, up to 2 μm in diam. Asci unitunicate, eight-spored, cylindrical, 145–250 × 8–28 μm, stipitate, with a thin apical ring, evanescent. Ascospores at first one-celled, hyaline, clavate, becoming transversely septate and two-celled; upper cell dark brown, obovoid to globose, truncate at the base, ornamented with warts arranged uniformly or forming longitudinal ridges or large spots, (12–)13–18(–29) × 6–27 μm, with an apical to lateral germ pore 0.5–3 μm in diam.; lower cell hyaline, conical, smooth-walled to slightly warted, 1–6 μm long, collapsing; gelatinous caudae absent. Asexual morph present. Conidia hyaline to pale-colored, almost smooth-walled, ovate to elongate, 2–6 × 1.5–2.5 μm, produced laterally or terminally on undifferentiated hyphae, solitary (adapted from Marin-Felix et al. 2020).
As mentioned above, the genus Strattonia is delimited based on the non-type species S. oblecythiformis, which should not be accepted due to the difficulty of delimiting genera in the Sordariales based on only morphological data (for further details, see section “New families superfluously introduced or without sufficient evidence”). For this reason, the new combination S. petrogale should not be taken up until further studies that include the type species confirm the correct taxonomic placement of the lineage representing Strattonia.
The nine new combinations in the newly erected genus Neoschizothecium proposed for accommodating the species previously belonging to Schizothecium are also here considered superfluous for the same reasons the family Neoschizotheciaceae is invalid. Moreover, N. minicauda was introduced to accommodate P. minicauda. However, the strain included in the phylogenetic study does not represent type material and its morphology was not studied. Therefore, the transfer of this species to Schizothecium should await further studies.
Cladorrhinum brunnescens is transferred to Podospora as P. brunnescens. However, in our phylogenetic study, this species is not placed in the well-supported clade (99% bs/1 pp) representing Podospora. Only ITS and LSU sequence data of the type strain are available. Therefore, the other two loci should be sequenced and additional analyses conducted before this combination is accepted.
Finally, two additional new combinations that followed poor taxonomic practices are Cl. leucotrichum and T. nannopodalis, which were proposed based on strains that do not represent type material and whose morphology was not studied.
Limitation in the morphological study
Huang et al. (2021) performed morphological studies of type material for several taxa belonging to the Sordariales, although they mostly repeated what can already be found in the literature without providing any new information while at the same time destroying irreplaceable type material. Examination of type material is important, but generating sequence data from types or designating epitypes with molecular data is a higher priority. No molecular data were generated in Huang et al. (2021). Due to the difficulty of delimiting species and genera of this order based only on morphology, it is much more important to generate sequences from these types of materials to incorporate in phylogenetic analyses instead of re-examining material that has previously been studied and well documented. This is the case of Triangularia horridula, a new combination proposed after a morphological and molecular study of the holotype from the fungarium of Saccardo (Forin et al. 2021). Using next-generation sequencing techniques, the generation of molecular data from type material is possible and essential to improve taxonomic classifications.
Conclusions and final remarks
In conclusion, it is clear that the authors of Huang et al. (2021) were not able to fully appreciate or understand the problems surrounding the reclassification of the order Sordariales, which has been studied using a combination of meticulous morphological and molecular analyses by various workers for more than a decade. Even in the last few years, chemotaxonomic data have been combined with morphological and molecular data to verify some taxonomic relationships. For example, Shao et al. (2020) demonstrated that different specimens and strains of Jugulospora produced the same xanthoquinodins compounds, corroborating the redefinition of the genus performed by Marin-Felix et al. (2020). Moreover, the new genus Pseudorhypophila was introduced based on the production of the same class of compounds, i.e. zopfinol and derivatives, by members of the same monophyletic lineage (Harms et al. 2021). In this later work, they observed that producers of sordarins, which are a class of natural antifungal agents, were all located in the Naviculisporaceae, supporting the introduction of this family based on molecular data by Marin-Felix et al. (2020). The taxonomy of the Sordariales should not be rearranged following the results of a single phylogenetic study and numerous new family names should not be introduced without careful consideration. The study of Huang et al. (2021) is reminiscent of those of Raymond Hoser (Kaiser et al. 2013; Rhodin et al. 2015; Wüster et al. 2021) or Alexander Doweld (2001), who frequently practice taxonomic vandalism by formally naming clades based on the work of previous workers. The introduction of unnecessary families, genera and species for unstable and unsupported clades that will eventually change justifies the criticisms of other mycological disciplines. These claim fungal taxonomists only want to constantly change names and make systematic mycology a more difficult field. New scientific names will remain in databases forever even if they are proven to be invalid or superfluous and have the potential to be used by future careless workers and further populated in the literature making them appear as valid and accepted names. Therefore, the introduction of new taxa should be done responsibly by following the best taxonomic practices available, such as a thorough review of past literature, conducting polyphasic studies to corroborate initial hypotheses and collaborating with experts in the group of fungi under study (Aime et al. 2020; Lücking et al. 2020).
Furthermore, it is possible that DNA-based phylogenies can be misleading in the recognition of species just like morphological studies alone. Polymorphisms can interfere in species identification based only on morphology, but also the lack of loci or the use of loci inappropriate for the fungal taxa under study can also lead to the wrong conclusions (Lücking et al. 2020). This is the case for some of the new combinations proposed by Huang et al. (2021) based only on ITS and LSU sequences. Therefore, both phenotypic and molecular approaches should be combined for a more robust taxonomic classification.
It is worthy to mention that according to the recent guidelines for publishing a new fungal species or name provided by Aime et al. (2020), it is strongly recommended to examine the types of the basionyms before making changes and include notes on how to differentiate the new recombined species from other similar species in that genus. Even though one of the co-authors of this guideline was also one of the authors of all new combinations proposed, none of these recommendations were followed in any of the new combinations performed by Huang et al. (2021).
Data availability
All data generated or analysed during this study are included in this published article (and its supplementary information files).
References
Aime MC, Miller AN, Aoki T et al (2020) How to publish a new fungal species, or name, version 3.0. IMA Fungus 12:11
Ament-Velásquez SL, Johannesson H, Giraud T et al (2020) The taxonomy of the model filamentous fungus Podospora anserina. MycoKeys 75:51–69
Bell A (1999) Podospora petrogale (Fungi, Sordariales: Lasiosphaeriaceae), a new species from Australia. Muelleria 12:235–240
Bell A, Mahoney DP, Debuchy R (2016) Podospora bullata, a new homothallic ascomycete from kangaroo dung in Australia. Ascomycete.org 8:111–118
Cai L, Jeewon R, Hyde KD (2005) Phylogenetic evaluation and taxonomic revision of Schizothecium based on ribosomal DNA and protein coding genes. Fungal Divers 19:1–21
Cai L, Jeewon R, Hyde KD (2006) Phylogenetic investigations of Sordariaceae based on multiple gene sequences and morphology. Mycol Res 110:137–150
Cailleux R (1969) Champignons stercoraux de Republique Centrafricaine, 3. Podospora nouveaux. Cahiers de la Maboké 7:87–102
Carmarán CC, Berretta M, Martínez S et al (2015) Species diversity of Cladorrhinum in Argentina and description of a new species, Cladorrhinum australe. Mycol Prog 14:94
Chang JH, Kao HW, Wang YZ (2010) Molecular phylogeny of Cercophora, Podospora, and Schizothecium (Lasiosphaeriaceae, Pyrenomycetes). Taiwana 55:110–116
Charria-Girón E, Surup F, Marin-Felix Y (2022) Diversity of biologically active secondary metabolites in the ascomycete order Sordariales. Mycol Progress 21:43
Corda ACJ (1838) Icones fungorum hucusque cognitorum. Annals and magazine of natural history 2:1–43
Crous PW, Shivas RG, Quaedvlieg W et al (2014) Fungal Planet description sheets: 214–280. Persoonia 32:184–306
Crous PW, Wingfield MJ, Burgess TI et al (2017) Fungal Planet description sheets: 625–715. Persoonia 39:270–467
Crous PW, Luangsa-ard JJ, Wingfield MJ et al (2018) Fungal Planet description sheets: 785–867. Persoonia 41:238–417
Dai DQ, Phookamsak R, Wijayawardene NN et al (2017) Bambusicolous fungi. Fungal Divers 82:1–105
Doweld A (2001) Prosyllabus Tracheophytorum: Tentamen Systematis Plantarum Vascularium (Tracheophyta). Moscow: GEOS.
Eriksson OE, Baral H-O, Currah RS et al (2001) Outline of Ascomycota-2001. Myconet 7:1–88
Fernández FA, Lutzoni FM, Huhndorf SM (1999) Teleomorph-anamorph connections: the new pyrenomycetous genus Carpoligna and its Pleurothecium anamorph. Mycologia 91:251–262
Fernández FA, Miller AN, Huhndorf SM et al (2006) Systematics of the genus Chaetosphaeria and its allied genera: morphological and phylogenetic diversity in north temperate and neotropical taxa. Mycologia 98:121–130
Forin N, Vizzini A, Fainelli F et al (2021) Taxonomic re-examination of nine Rosellinia types (Ascomycota, Xylariales) stored in the Saccardo mycological collection. Microorganisms 9:666
García D, Stchigel AM, Cano J et al (2004) A synopsis and re-circumscription of Neurospora (syn. Gelasinospora) based on ultrastructural and 28S rDNA sequence data. Mycol Res 108:1119–1142
Geydan TD, Debets AJ, Verkley GJ et al (2012) Correlated evolution of senescence and ephemeral substrate use in the Sordariomycetes. Mol Ecol 21:2816–2828
Górz A, Boroń P (2018) Episternus onthophagi: a new monotypic genus of epizoic fungus found on Onthophagus beetles (Scarabaeoidea). Phytotaxa 376:43
Greif MD, Stchigel AM, Miller AN et al (2009) A re-evaluation of genus Chaetomidium based on molecular and morphological characters. Mycologia 101:554–564
Harms K, Milic A, Stchigel AM et al (2021) Three new derivatives of zopfinol from Pseudorhypophila mangenotii gen. et comb. nov. J Fungi 7:181
Hawksworth DL, Eriksson OE (1986) The names of accepted orders of Ascomycetes. Syst Ascomycetum 5:175–184
Huang SK, Hyde KD, Mapook A et al (2021) Taxonomic studies of some often over-looked Diaporthomycetidae and Sordariomycetidae. Fungal Divers 111:443–572
Huhndorf SM, Miller AN, Fernández FA (2004) Molecular systematics of the Sordariales: the order and the family Lasiosphaeriaceae redefined. Mycologia 96:368–387
Kaiser H, Crother BI, Kelly CMR et al (2013) Best practices: in the 21st century, taxonomic decisions in herpetology are acceptable only when supported by a body of evidence and published via peer-review. Herpetol Rev 44:8–23
Kruys Å, Huhndorf SM, Miller AN (2015) Coprophilous contributions to the phylogeny of Lasiosphaeriaceae and allied taxa within Sordariales (Ascomycota, Fungi). Fungal Divers 70:101–113
Lücking R, Aime MC, Robbertse B et al (2020) Unambiguous identification of fungi: where do we stand and how accurate and precise is fungal DNA barcoding? IMA Fungus 11:14
Lundqvist N (1972) Nordic Sordariaceae s. lat. Symb. Bot Upsal 20:1–374
Madrid H, Cano J, Stchigel A et al (2010) Ramophialophora humicola and Fibulochlamys chilensis, two new microfungi from soil. Mycologia 102:605–612
Madrid H, Cano J, Gené J et al (2011) Two new species of Cladorrhinum. Mycologia 103:795–805
Marin-Felix Y, Miller AN, Cano-Lira JF et al (2020) Re-evaluation of the order Sordariales: delimitation of Lasiosphaeriaceae s. str., and introduction of the new families Diplogelasinosporaceae, Naviculisporaceae, and Schizotheciaceae. Microorganisms 8:1430
Miller AN (2003) A reinterpretation of the pseudo-bombardioid ascomal wall in taxa in the Lasiosphaeriaceae. Sydowia 55(2):267–273
Miller AN, Huhndorf SM (2004a) A natural classification of Lasiosphaeria based on nuclear LSU rDNA sequences. Mycol Res 108:26–34
Miller AN, Huhndorf SM (2004b) Using phylogenetic species recognition to delimit species boundaries within Lasiosphaeria. Mycologia 96:1106–1127
Miller AN, Huhndorf S (2005) Multi-gene phylogenies indicate ascomal wall morphology is a better predictor of phylogenetic relationships than ascospore morphology in the Sordariales (Ascomycota, Fungi). Mol Phylogenet Evol 35:60–75
Nygren K, Strandberg R, Wallberg A et al (2011) A comprehensive phylogeny of Neurospora reveals a link between reproductive mode and molecular evolution in fungi. Mol Phylogenet Evol 59:649–663
Raja HA, Schoch CL, Hustad VP et al (2011) Testing the phylogenetic utility of MCM7 in the Ascomycota. MycoKeys 1:63–94
Réblová M (2008) Bellojisia, a new sordariaceous genus for Jobellisia rhynchostoma and a description of Jobellisiaceae fam. nov. Mycologia 100:893–901
Rhodin AGJ, Kaiser H, van Dijk PP et al (2015) Comment on Spracklandus Hoser, 2009 (Reptilia, Serpentes, ELAPIDAE): request for confirmation of availability of the generic name and for the nomenclatural validation of the journal in which it was published. Bull Zool Nomencl 72:65–78
Shao L, Marin-Felix Y, Surup F et al (2020) Seven new cytotoxic and antimicrobial xanthoquinodins from Jugulospora vestita. J Fungi 6:188
Stchigel AM, Cano J, Miller AN et al (2006) Corylomyces: a new genus of Sordariales from plant debris in France. Mycol Res 110:1361–1368
Vogan AA, Miller AN, Silar P (2021) (2803) Proposal to change the conserved type of Podospora, nom. cons. (Ascomycota). Taxon 70:429–430
von Niessl G (1883) Über die Theilung der Gattung Sordaria. Hedwigia 22:153–156
Vu D, Groenewald M, de Vries M et al (2019) Large-scale generation and analysis of filamentous fungal DNA barcodes boosts coverage for kingdom Fungi and reveals thresholds for fungal species and higher taxon delimitation. Stud Mycol 92:135–154
Wang XW, Houbraken J, Groenewald JZ et al (2016a) Diversity and taxonomy of Chaetomium and chaetomium-like fungi from indoor environments. Stud Mycol 84:145–224
Wang XW, Lombard L, Groenewald JZ et al (2016b) Phylogenetic reassessment of the Chaetomium globosum species complex. Persoonia 36:83–133
Wang XW, Bai FY, Bensch K et al (2019a) Phylogenetic re-evaluation of Thielavia with the introduction of a new family Podosporaceae. Stud Mycol 93:155–252
Wang XW, Yang FY, Meijer M et al (2019b) Redefining Humicola sensu stricto and related genera in the Chaetomiaceae. Stud Mycol 93:65–153
Wu B, Tian J-Q, Wang L et al (2016) Apiosordaria hamata sp. nov. from lake sediment in China. Mycotaxon 131:847–857
Wüster W, Thomson SA, O’Shea M et al (2021) Confronting taxonomic vandalism in biology: conscientious community self-organization can preserve nomenclatural stability. Biol J Linn Soc 10:1–26
Zhang ZF, Liu F, Zhou X et al (2017) Culturable mycobiota from Karst caves in China, with descriptions of 20 new species. Persoonia 39:1–31
Zhang ZF, Zhao P, Cai L (2018) Origin of cave fungi. Front Microbiol 9:1407
Acknowledgements
The authors wish to thank Prof. Dr. Pedro Crous for examining the epitype of Podospora fimiseda.
Funding
Open Access funding enabled and organized by Projekt DEAL. This research was funded by Deutsche Forschungsgemeinschaft (DFG) – Project-ID 490821847.
Author information
Authors and Affiliations
Contributions
Conceptualization, Y. M.-F. and A. N. M.; writing-original draft preparation, Y. M.-F. and A. N. M.; writing-review and editing, Y. M.-F. and A. N. M.; all authors have read and agreed to the published version of the manuscript.
Corresponding author
Ethics declarations
Conflict of interest
The authors declare no competing interests.
Additional information
Section editor: Roland Kirschner
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary information
ESM 1
(DOCX 236 kb)
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
About this article
Cite this article
Marin-Felix, Y., Miller, A.N. Corrections to recent changes in the taxonomy of the Sordariales. Mycol Progress 21, 69 (2022). https://doi.org/10.1007/s11557-022-01814-z
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1007/s11557-022-01814-z