DNA extractions, PCR and DNA sequencing

DNA extractions were performed using UltraClean Microbial DNA Isolation Kits (MO BIO Laboratories Inc., Carlsbad, California) from mycelium scraped from colonies grown on PDA using a sterile scalpel. DNA concentration and quality were determined by Nanodrop ND-1000 spectrometer (Thermo Scientific, Wilmington, Delaware) and preparations were diluted to 1–5 ng/μL of DNA template.

The second largest subunit of the RNA polymerase II (rpb2) was amplified following the protocol of de Cock & Lévesque (2004) using the primer combinations 5F2/7cR and 7cF/11aR (O'Donnell et al. 2007) in a total reaction volume of 20 μL. PCR products of the larger subunit of the ATP citrate lyase (acl1, Nowrousian et al. 2000) was amplified using the newly designed primers acl1-230up (5'-AGC CCG ATC AGC TCA TCA AG-3') and acl1-1220low (5'-CCT GGC AGC AAG ATC VAG GAA GT-3') in a total reaction volume of 20 μL following the same protocol. PCR reactions were placed in an Eppendorf thermal cycler (Westbury, New York) and processed with the following temperature profile for the rbp2 regions: 3 min at 95 °C (initial denaturation), 5 cycles 45 s at 95 °C (denaturation), 45 s at 60 °C (annealing), 2 min at 72 °C (extension), followed by 5 cycles with annealing at 58 °C, followed by 30 cycles with annealing at 54 °C, with a final extension 8 min at 72 °C. The temperature profile for the acl1 region was as follows: 3 min at 95 °C, 5 cycles 45 s at 95 °C, 45 s at 64 °C, 2 min at 72 °C, followed by 5 cycles with annealing at 62 °C, followed by 30 cycles with annealing at 56 °C, with a final extension 8 min at 72 °C. For forward and reverse strands, sequencing reactions were performed directly without cleaning PCR amplicons, using a BigDye sequencing kit (Applied Biosystems, Foster City, California) on an ABI3130 DNA Analyzer (Applied Biosystems). The following profile was used for the sequencing reactions: 95 °C for 3 min, then for 40 cycles at 95 °C for 30 s, 50 °C for 15 s, 60 °C for 2 min. Contig sequences were assembled using Sequencher v. 4.9 (Gene Codes Corporation, Ann Arbor, Michigan) and aligned manually using BioEdit 7 (Hall 1999). Protein coding DNA sequences were aligned along the reading frame of the corresponding amino acid sequence and divided into 3 partitions, rpb2 region 5–7, rpb2 region 7–11, and acl1. Intergenic spacer regions and introns of the rpb2 and acl1 gene sequences could not be reliably aligned and were excluded from the final alignment. Additional ITS sequences were generated for some of the species mentioned below using the methods described by Nguyen & Seifert (2008).

All DNA sequences generated in this study are deposited in GenBank (accession numbers listed in Table 1 and in the Taxonomy part as barcodes). We have designated some of these as “DNA barcodes” when they represent type, authentic, or thoroughly validated strains.

Phylogenetic analyses

One hundred independent ML analyses under the GTR + I + G nucleotide substitution model of the combined and partitioned data set (rpb2 5–7 with 488 parsimony-informative characters, rpb2 7–11 with 387 parsimony-informative characters, and acl1 with 206 parsimony-informative characters) resulted in a single best ML tree with –lnL = –57,309.9782 (not shown). The parameters for the GTR + I + G model of the rpb2 5–7 partition were as follows: Estimated base frequencies; A = 0.2098, C = 0.2885, G = 0.2691, T = 0.2326; substitution rates AC = 2.104, AG = 6.386, AT = 2.011, CG = 0.767, CT = 9.725, GT = 1.000; proportion of invariable sites I = 0.3861; gamma distribution shape parameter α = 0.8858. The parameters for the GTR + I + G model of the rpb2 7–11 partition were as follows: Estimated base frequencies; A = 0.2033, C = 0.3050, G = 0.2538, T = 0.2379; substitution rates AC = 1.680, AG = 7.167, AT = 2.089, CG = 0.914, CT = 10.966, GT = 1.000; proportion of invariable sites I = 0.5253; gamma distribution shape parameter α = 0.8815. The parameters for the GTR + I + G model of the acl1 partition were as follows: Estimated base frequencies; A = 0.1774, C = 0.3655, G = 0.2369, T = 0.2202; substitution rates AC = 0.982, AG = 2.844, AT = 0.638, CG = 0.839, CT = 7.876, GT = 1.000; proportion of invariable sites I = 0.4834; gamma distribution shape parameter α = 0.9192.

Ten independent ML analyses under the codon substitution model (M3 with K = 3) of the combined and partitioned data set (rpb2 5–7 with 294 parsimony-informative characters, rpb2 7–11 with 292 parsimony-informative characters, and acl1 with 145 parsimony-informative characters) resulted in a single best ML tree with –lnL = –54,991.4885 (Fig. 1). The parameters for the M3 codon model of the rpb2 5–7 partition were as follows: 61 empirical codon frequencies (F3×4 method); substitution rates AC = 1.234, AG = 2.380, AT = 1.222, CG = 0.743, CT = 2.758, GT = 1.000; and three estimated nonsynonymous rate categories ω1 = 0.0020 with p1 = 0.6471, ω2 = 0.0726 with p2 = 0.2452, ω3 = 0.3214 with p3 = 0.1077. The parameters for the M3 codon model of the rpb2 7–11 partition were as follows: 61 empirical codon frequencies (F3×4 method); substitution rates AC = 1.023, AG = 2.820, AT = 1.177, CG = 0.933, CT = 2.489, GT = 1.000; and three estimated non-synonymous rate categories ω1 = 0.0020 with p1 = 0.8918, ω2 = 0.0925 with p2 = 0.0985, ω3 = 0.5436 with p3 = 0.0097. The parameters for the M3 codon model of the acl1 partition were as follows: 61 empirical codon frequencies (F3×4 method); substitution rates AC = 1.863, AG = 3.515, AT = 1.290, CG = 1.264, CT = 3.346, GT = 1.000; and three estimated non-synonymous rate categories ω1 = 0.0031 with p1 = 0.8025, ω2 = 0.1007 with p2 = 0.1211, ω3 = 0.4420 with p3 = 0.0763. These dN/dS ratios (ω < 1) verify a significant departure from neutrality (ω ≈ 1) of the rpb2 and acl1 data partitions implying natural selection against changes of amino acids in the encoding genes studied.

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Fig. 1.

(p. 89). Maximum likelihood (ML) tree under the M3 codon model inferred from combined rpb2 + acl1 gene sequence data set. Negative-log likelihood (-lnL) of the ML tree is –54,991.4885. Branches with ML-BP and MP-BP values of > 75 % and PP scores > 0.95 are in bold. Internodes that are supported with individual values of ML-BP or MP-BP > 75 % or PP scores > 0.95, respectively, are drawn in bold and grey. Symbols following strain numbers indicate different morphs known for the species: ○ = microconidial state, = Fusarium-like macroconidial state, = teleomorph. Vertical bars in red indicate members of Cosmospora sensu Rossman et al. (1999), yellow bars taxa of the basal Fusarium-like clade, and a dark grey bar species of the terminal Fusarium clade, respectively.

In comparison, the best ML tree for the M3 codon model received a significantly better negative-log likelihood score than the best ML tree under the GTR + I + G nucleotide substitution model. The topology of the phylograms did not differ for the clades studied. Only some basal lineages such as “Nectria” diminuta, “N.” rubropeziza, and “Pseudonectria” pachysandricola grouped differently using different substitution models, probably a result of long branch attraction.

Similarily, heuristic searches of the parsimony analysis yielded a single most parsimonious tree (not shown), which did not have a significantly different topology than that of the ML analyses. The MP tree was 14 023 steps with a consistency index (CI) of 0.152, a retention index (RI) of 0.492, a rescaled CI (RC) of 0.075, and a homoplasy index (HI) of 0.848.

1 000 ML pseudoreplicates, two independent MCMC analyses, and 1 000 heuristic bootstrap replicates of the combined and partitioned data set conducted with GARLI, MrBayes and PAUP, respectively, yielded majority consensus trees with highly concordant topologies (not shown) similar to that of the best ML tree generated for the M3 codon model. Internodes with significant clade support are drawn in thicker lines on the best ML tree topology (Fig. 1). Nodes were considered strongly supported when ML bootstrap proportions (ML-BP) is ≥ 75 %, Bayesian posterior probabilities (PP) is ≥ 0.95, and MP bootstrap proportions (MP-BP) is ≥ 75 % (Lutzoni et al. 2004).

Polyphyly of Cosmospora sensu Rossman

In the best ML tree (Fig. 1), species formerly placed in Cosmospora sensu Rossman fall into several major clades. The first major clade includes Volutella with four strains of three species, V. ciliata, V. citrinella (“Cosmospora” stilbellae) and V. consors (“C.” consors), in a strongly supported clade. Chaetopsina penicillata (= Chaetopsinectria or “Cosmospora” chaetopsinae-penicillatae) is a well supported sister species of Volutella, confirming the close phylogenetic relationship of Chaetopsina and Volutella (Zhang & Zhuang 2006, Luo & Zhuang 2010). Although not strongly supported, the Volutella/Chaetopsina group is the sister clade to a diverse fungal clade consisting of species of Calonectria, Cylindrodendrum, Heliscus, Mariannaea, and Neonectria.

The second major clade includes species formerly classified as Nectria applanata, Cosmospora purtonii, and C. wegeliniana. This clade is strongly supported and comprises species having ascomata with perithecial walls mainly consisting of two regions, and which are probably host-specific. These species are transferred to Stylonectria in the taxonomic section below.

The third and largest clade includes several subclades including the type species of Cosmospora, C. coccinea, and species with Fusarium-, Acremonium- and Verticillium-like anamorphs, which are classified in Cosmospora sensu stricto, Dialonectria, Fusicolla, Macroconia, and Microcera below. Cosmospora coccinea forms a strongly supported clade with other well-known species of the genus with Acremonium-like anamorphs, such as C. butyri, C. cymosa, and C. viridescens. This clade contains a group of species with similar microconidial anamorphs and a fairly constant ecological niche, delineating the new generic concept of Cosmospora s. str. Basal to Cosmospora is the strongly supported Dialonectria clade, which contains D. episphaeria and a new species, D. ullevolea. With “Nectria” rishbethii as a sister species, this subclade is delimited from another strongly supported subclade with species of Macroconia and Microcera, and Fusicolla matuoi. Macroconia and Microcera are sister clades, and include species such as Macroconia papilionacearum and Mac. leptosphaeriae as well as Microcera coccophila, Mic. diploa, and Mic. larvarum. These subclades, together with a few “residual” species classified in Fusarium such as “F.” cavispermum, “F.” ciliatum, “F.” melanochlorum, and “F.” merismoides var. chlamydosporale, are all phylogenetically distinct from the terminal Fusarium clade discussed below.

The terminal Fusarium clade contains a group of fungi with Cosmospora-like teleomorphs, of which only “Nectria” zealandica was formally combined in Cosmospora (Nirenberg & Samuels 2000). The terminal clade includes “Nectria” desmazieri and “N.” atrofusca, and is dealt with in more detail by Schroers et al. (2011).

As a singleton, “Nectria” diminuta does not group with any of the clades mentioned above. In all analyses under various substitution models (data not shown), “N.” diminuta fell neither in the terminal Fusarium clade nor the basal Fusarium-like clade nor any of the Cosmospora sensu Rossman groups (Fig. 1). This positional artifact may be caused by long-branch attraction or a paucity of parsimony-informative characters for the basal taxa in the combined DNA sequence data set.

Polyphyly of Fusarium sensu Wollenweber

The genus Fusarium is taxonomically linked to the teleomorph genus Gibberella, because they share the same species as type, F. sambucinum and G. pulicaris. In nature, Gibberella teleomorphs occur less frequently than their Fusarium anamorphs (Rossman et al. 1999). In the ML tree (Fig. 1), the Gibberella clade, representing Fusarium in the strict sense and including the type species in addition to F. graminearum, F. sublunatum, and F. verticillioides, is strongly supported. In Fig. 1 and Schroers et al. (2011), Gibberella is the sister clade to Cyanonectria. The terminal Fusarium clade in Fig. 1, including species with teleomorphs described in Albonectria, Cyanonectria, Gibberella, Haematonectria, and Neocosmospora, did not receive a statistically significant support similar to that obtained in other phylogenetic analyses (Schroers et al. 2009). The basal lineage of the terminal Fusarium clade is represented by the “Nectria” ventricosa species complex. Within the terminal Fusarium group, members of Albonectria and the Haematonectria/Neocosmospora species complex as well as the species pair “Albonectria” albida and “Fusarium” nematophilum always formed strongly supported groups.

The basal Fusarium-like clade, with numerous members formerly classified in Fusarium sections Arachnites, Eupionnotes, Macroconia, Pseudomicrocera, and Submicrocera, is phylogenetically and phenotypically distinct from the terminal Fusarium clade mentioned above. The basal clade splits into several subclades similar to what is described above for Cosmospora sensu Rossman. Therefore we have given these groups genus rank in the taxonomy part below.

Another genus of Fusarium-like species is represented by Atractium. Atractium crassum (“Fusarium” merismoides var. crassum) did not fall within the basal or terminal Fusarium clades. Together with Atractium stilbaster, it forms a strongly supported sister lineage to a group of fungi including species of Chaetopsina, Pseudonectria, and Volutella.

Accepted species

Atractium stilbaster Link 1809, Mag. Ges. naturf. Freunde, Berlin 3: 10.
Basionym: Fusarium stilbaster (Link) Link in Willdenow, Sp. pl., Edn 4 6(2): 106. 1825 (1824).

• = Atractium fuscum Sacc., Syll. Fung. 2: 514. 1883.

• ≡ Stilbella fusca (Sacc.) Seifert, Stud. Mycol. 35: 77. 1985.

See Seifert (1985a, as Stilbella fusca) for other synonyms.

Typification: Illustration published in Mag. Ges. naturf. Freunde, Berlin 3 as tab. I, fig. 11, lectotype designated here, reproduced here as Fig. 2B. epitype of A. stilbaster designated here: Germany, Bayrischer Wald, Rachelseewand, on bark, Jul. 1967, W. Gams, CBS 410.67.

Other material examined: See Seifert (1985a). Canada, Quebec, Gatineau Park, Lac Bourgeous, on cut end of stump, Jul. 1992, K.A. Seifert, DAOM 215627.

Notes: Seifert (1985a) provided illustrations and a complete description of this species. The variability in conidium dimensions and septation reported by Seifert (1985a) may indicate the existence of several closely related but possibly morphologically diagnosable species.

Atractium crassum (Wollenw.) Seifert & Gräfenhan, comb. & stat. nov. MycoBank MB519420.
Basionym: Fusarium merismoides var. crassum Wollenw., Fus. autogr. del. 3: 857. 1930. (The publication of the same species in Zeitschrift für Parasitenkunde 3(3): 308. 1931 was apparently after the cited 1930 publication).

Typification: Germany, Berlin, isolated from drinking water, 1928, H.W. Wollenweber 3119, lectotype designated here, CBS. ex-type cultures CBS 180.31 = NRRL 20894. GenBank barcodes: HQ897722 (rpb2), HQ897859 (acl1).

Notes: This species was described and illustrated by Wollenweber (1930, reproduced here as Fig. 2A), Wollenweber & Reinking (1935), and Gerlach & Nirenberg (1982). The strains described by the latter authors are now degenerated, and the following details come from their description. Fresh cultures grow slowly, 15–30 mm diam after 10 d on PDA, and sometimes produce Coremium-like structures. The macroconidia are gently curved with a rounded to somewhat conical basal cell and a rounded apical cell; there is no foot to the basal cell. They are mostly 3–5-septate; 3-septate conidia average 52 × 5 μm (ranging 37–60 × 4.5–5.5), 4–5-septate 60 × 5.5 μm (50–65 × 5-6), 1–2 septate 31 × 4.5 μm (25–37 × 3–6). Chlamydospores are terminal, intercalary or in conidia, round, 7–12 μm diam.

A second culture, BBA 62257, was illustrated by Gerlach (1972) and Gerlach & Nirenberg (1982) but is no longer available. A dried culture kept in the CBS herbarium is designated as lectotype above, because it is the only known original material. Wollenweber's published illustration of the type strain (Fig. 2A) represents the macroconidia of his taxon well. Epitypification must await the isolation of a fresh culture and specimen that can demonstrate the salient morphological features more completely than the existing cultures.

This species developed in damp chambers on small twigs collected from cold, running river water in Ontario, Canada, but the cultures were not preserved and the fungus cannot be relocated on the original specimen. Attempts to recollect and reisolate the fungus from the same locality were unsuccessful. The conidiomata on the natural substrate were glistening white and flame-shaped; the bundles of parallel macroconidia give the appearance of minute synnemata (Fig. 2C). However, little conidiomatal tissue is actually produced, and the phialides arise from a typical, Fusarium-like sporodochium of interwoven but not stromatic hyphae and conidiogenous cells.

Atractium holubovae (Seifert, S.J. Stanley & K.D. Hyde) Seifert, comb. nov. MycoBank MB519421.
Basionym: Stilbella holubovae Seifert, S.J. Stanley & K.D. Hyde, Sydowia 47: 258, 1995.

Typification: Philippines, Negros Occiental, Bario Caliban, Caliban River, on submerged wood, Dec. 1994, K.D. Hyde & E. Arimas, holotype DAOM 214961.

Notes: This species was described and illustrated by Seifert et al. (1995) in the absence of pure cultures and is transferred here on the basis of its morphological similarity with A. stilbaster. It is known from the holotype and two subsequent records on submerged wood collected from streams in Asia (Sivichai et al. 2002, Fryar et al. 2004).

Cosmospora Rabenh., Hedwigia 2: 59. 1862.

Type species: Cosmospora coccinea Rabenh. 1862.

Stroma inconspicous or absent. Perithecia scattered to gregarious, pyriform with an acute or apical papilla, collapsing cupulate or pinched when dry, orange red or bright red, turning dark red in KOH+, smooth walled, usually 150–450 μm high. Asci cylindrical to narrowly clavate, with an apical ring, 8 uniseriate or partly biseriate ascospores. Ascospores initially hyaline but becoming yellow brown to reddish brown, 1-septate, becoming tuberculate when mature. Conidiophores Acremonium-like, either lateral phialides on somatic hyphae, or with one or two layers of monochasial branching, or verticillate, hyaline. Phialides monophialidic, cylindrical to subulate, hyaline. Microconidia ellipsoidal, oblong or clavate or slightly allantoid, aseptate, hyaline, in slimy heads. Macroconidia absent. Chlamydospores usually not seen, but produced on some media.

Colonies on PDA slow growing, 15–25 mm diam in 14 d at room temperature, surface powdery, felt-like, floccose, cottony, white, pale pink, ochre to olivaceous green, sporulation usually abundant, arising directly from agar surface or from sometimes abundant aerial mycelium.

Habitat: On fruiting bodies and stromata of other fungi, e.g. Fomitopsis, Hypoxylon, Inonotus, Stereum, often isolated from soil.

Notes: About 65 species have been attributed to Cosmospora sensu Rossman. This concept is relatively broad, encompassing a great deal of anamorphic variability, although the teleomorph morphology is relatively conserved, with small, orange or reddish KOH+ perithecia with thin walls, cylindrical asci with or without an apical ring, and eight, uniseriate, 1-septate ascospores; stroma development is usually limited. Our phylogenetic analyses (Fig. 1) identify several distinct lineages within the prevailing concept of Cosmospora. New teleomorph genera have already been proposed for some lineages, namely Nectricladiella (a synonym of the anamorphically typified genus Cylindrocladiella) and Chaetopsinectria (a synonym of the anamorphically typified genus Chaetopsina). In general, well-supported clades correlate with anamorph types, although Fusarium-like anamorphs are found in several lineages.

Here, we propose a more restricted concept for Cosmospora, limiting it to the clade of species surrounding the type, C. coccinea, which have only microconidial, Acremonium-like anamorphs and tend to occur on other fungi. Other microconidial genera recognised are Mariannaea and Volutella. The clades with Fusarium-like anamorphs are reclassified below in the reintroduced genera Dialonectria, Fusicolla, and Microcera, with Macroconia elevated to generic rank from its previous sectional rank in Nectria. A small residue of species remains in Cosmospora sensu Rossman that are not redisposed here.

Although several of the new combinations propose the transfer of an anamorph typified name to a teleomorphically typified genus, as explained in the Introduction, the results are correct, legitimate, and valid for those species that are not pleomorphic, i.e. those that lack a teleomorph and are outside Art. 59 of the ICBN.

Accepted species

Cosmospora coccinea Rabenh., Hedwigia 2: 59. 1862 [non Nectria coccinea (Pers.) Fr. 1849].

• = Verticillium olivaceum W. Gams, Cephalosporium-artige Schimmelpilze, p. 129. 1971.

Typification: Germany, near Laubach, on rotting pores of a polypore, Solms, Fungi europaei no. 459, lectotype BPI designated by Rossman et al. 1999.

Other material examined: Germany, Bayrischer Wald, Arberseewand, on hymenium of Inonotus nodulosus on Fagus sylvatica, Aug. 1967, W. Gams 680, CBS 341.70 = VKM F-2863; Kr. Plön, near Dobersdorf, on hymenium of Inonotus radiatus on Alnus, Oct. 1965, W. Gams 1104, CBS 343.70; Eifel, Geeser Wald near Gerolstein, on Inonotus radiatus, Sep. 1970, W. Gams, CBS 841.70; Eifel, Geeser Wald near Gerolstein, on Inonotus radiatus, Sep. 1970, W. Gams, CBS 983.70 = VKM F-2862; Neubrandenburg, Kleppelshager Forst near Friedland, on Inonotus radiatus, Oct. 1978, P. Hübsch H78/40, CBS 704.79; Bayern, on Inonotus nodulosus, dead crust, on fallen branch of Fagus sylvatica, 1993, T.R. Lohmeyer & R. Boesmiller 93/62, A.R. 2741 = BPI 802729 = CBS 114050; Nordrhein-Westfalen, Detmold, Krebsteich, on Inonotus nodulosus on Fagus sylvatica, Apr. 2007, T. Gräfenhan 2007-37, DAOM 235821.

Notes: For descriptions, illustrations, and additional taxonomic synonyms of the microconidial anamorph, see Gams (1971); the teleomorph is briefly described by Rossman et al. (1999).

Cosmospora arxii (W. Gams) Gräfenhan & Schroers, comb. nov. MycoBank MB519422.
Basionym: Acremonium arxii W. Gams, Cephalosporium-artige Schimmelpilze, p. 123. 1971.

Typification: Germany, Niedersachsen, near Wilhelmshaven, Neuenburger Urwald, on Hypoxylon sp., May 1965, W. Gams, holotype CBS H-6635, ex-type culture CBS 748.69 GenBank barcodes: HQ897725 (rpb2), HQ897862 (acl1).

Other material examined: Germany, Nordrhein-Westfalen, Kamen, Heerener Holz, on Hypoxylon on Fagus, Apr. 2007, T. Gräfenhan 2007-22, DAOM 235822; Nordrhein-Westfalen, Detmold, Externsteine, on Hypoxylon on Fagus sylvatica, Apr. 2007, T. Gräfenhan 2007-28, DAOM 235823; Nordrhein-Westfalen, Detmold, Donoper Teich, on Hypoxylon on Fagus sylvatica, Apr. 2007, T. Gräfenhan 2007-29, DAOM 235824 & T.G. 2007-33, DAOM 235825; USA, Pennsylvania, near Salt Springs State Park, on Hypoxylon on Acer, May 2007, T. Gräfenhan 2007-55, DAOM 235826.

Notes: The teleomorph of Cosmospora arxii is commonly found on Hypoxylon spp. on Fagus in North America and Europe, but has not been described yet; its morphology is similar to that of C. viridescens. For a description, illustrations, and discussion of the microconidial anamorph, see Gams (1971) and notes under C. berkeleyana below.

Cosmospora berkeleyana (P. Karst.) Gräfenhan, Seifert & Schroers, comb. nov. MycoBank MB519423.
Basionym: Verticillium berkeleyanum P. Karst., Meddeland. Soc. Fauna Fl. Fenn. 18: 64. 1891.

• ≡ Acremonium berkeleyanum (P. Karst.) W. Gams, Netherlands J. Pl. Pathol. 88: 76. 1982.

Typification: Finland, near Mustiala, on Stereum hirsutum on Betula, Oct. 1890, P.A. Karsten 2310, holotype H.

Notes: For a description and discussion of this microconidial species, see Karsten (1891) and Gams & Zaayen (1982).

Although some have considered the teleomorph to be the heterotypic Hypomyces berkeleyanus Plowr. & Cooke (≡ Sphaerostilbella berkeleyana (Plowr. & Cooke) Samuels & Candoussau), our observations complicate the situation considerably. Because our phylogenetic results suggest that this is a species complex, the proposed synonyms applied to the teleomorph-anamorph connections for Cosmospora berkeleyana need to be re-evaluated (Fig. 1). These synonyms include Acremonium butyri, Cephalosporium khandalense, Gliomastix lavitskiae, Nectria vilior, and N. viridescens (Gams 1971, Samuels et al. 1990, Rossman et al. 1999). In our phylogenetic analysis, all of these putative synonyms can be interpreted as distinct species of Cosmospora.

Cosmospora berkeleyana, C. vilior, and C. viridescens have often been considered synonymous, but this now seems unlikely and each name must be re-evaluated. Samuels et al. (1990, 1991) studied and discussed the type material of C. vilior on a valsaceous stroma from Brazil. Because no fresh material from subtropical South America is available, we are unable to reinterpret Samuels' concept in phylogenetic terms. Cosmospora viridescens was described from a fungal host on Salix in Europe and thus may have distinct host relationships and geographical distribution. Possible morphological distinctions between these two teleomorphs are discussed below under C. viridescens.

Gams & Zaayen (1982) studied a recent specimen and culture identified as Acremonium berkeleyanum, which was unavailable for our study (The Netherlands, Oostelijk Flevoland, Abbert-bos, perceel O66, on Stereum hirsutum, July 1981, W. Gams, CBS 501.81). A similar fungus producing perithecia and the characteristic greenish Acremonium-like anamorph on basidiocarps of S. hirsutum on Alnus rubra is common in British Columbia, Canada (Seifert, unpubl. data).

Until species limits can be more clearly established, we prefer not to epitypify C. berkeleyana or C. vilior. The diversity of substrates and broad geographic distribution recorded for C. berkeleyana (Gams 1971, www.cbs.knaw.nl/databases) suggest that additional phylogenetic species await discovery in this complex.

Cosmospora butyri (J.F.H. Beyma) Gräfenhan, Seifert & Schroers, comb. nov. MycoBank MB519428.
Basionym: Tilachlidium butyri J.F.H. Beyma, Zentralbl. Bakteriol., 2 Abt. 99: 388. 1938.

• ≡ Acremonium butyri (J.F.H. Beyma) W. Gams, Cephalosporium-artige Schimmelpilze, p. 126. 1971.

Typification: Denmark, Copenhagen, butter, Knudsen, holotype CBS H-6601, ex-type cultures CBS 301.38 = MUCL 9950. GenBank barcodes: HQ897729 (rpb2), HQ897866 (acl1).

Notes: No teleomorph is known, but see notes under C. berkeleyana above. This microconidial species is described, illustrated, and discussed by van Beyma (1938) and Gams (1971). As noted by Summerbell et al. (2011), there may be more than one fungus preserved as CBS 301.38; we have not examined the holotype specimen.

Cosmospora cymosa (W. Gams) Gräfenhan & Seifert, comb. nov. MycoBank MB519429.
Basionym: Acremonium cymosum W. Gams, Cephalosporium-artige Schimmelpilze, p. 131. 1971.

Typification: Germany, Schleswig-Holstein, Kr.Rendsburg, Enkendorfer Gehölz, on decaying Inonotus radiatus, Oct. 1965, W. Gams, lectotype designated here CBS H-5054, isotype CBS H-6603, ex-type culture CBS 762.69. GenBank barcodes: HQ897778 (rpb2), HQ897914 (acl1).

Other material examined: Germany, Kr.Plön, Dobersdorfer Wald, on Inonotus radiatus on Alnus glutinosa, June 1965, W. Gams 512A, CBS H-8146, CBS 258.70.

Notes: For description and illustrations of this microconidial anamorphic species, see Gams (1971). No teleomorph is known.

Cosmospora khandalensis (Thirum. & Sukapure) Gräfenhan & Seifert, comb. nov. MycoBank MB519430.
Basionym: Cephalosporium khandalense Thirum. & Sukapure, Mycologia 58: 359. 1966.

Typification: India, Maharashtra, Khandala, on decaying stem of Bambusa, Aug. 1964, M.J. Thirumalachar, holotype HACC 148, isotype CBS H-15076, ex-type cultures ATCC 16091 = CBS 356.65 = IMI 112790 = MUCL 7974. GenBank barcodes: HQ897723 (rpb2), HQ897860 (acl1).

Notes: The microconidial anamorph of this species as typified here is described and illustrated by Sukapure & Thirumalachar (1966) and discussed by Gams (1971). See notes above under C. berkeleyana.

Cosmospora lavitskiae (Zhdanova) Gräfenhan & Seifert, comb. nov. MycoBank MB519431.
Basionym: Gliomastix lavitskiae Zhdanova, Mikrobiol. Zhurn. 28: 37. 1966.

Typification: Ukraine, Poltawa region, on plant debris from rhizosphere soil of Zea mays, July 1961, holotype D.K. Zabolotny Institute of Microbiology and Virology of the National Academy of Sciences of Ukraine, ex-type cultures ATCC 18666 = CBS 530.68 = IMI 133984 = VKM F-1324. GenBank barcodes: HQ897726 (rpb2), HQ897863 (acl1).

Notes: The microconidial anamorph of the species is described and illustrated by Zhdanova (1966) and discussed by Gams (1971). No teleomorph is known. See notes above under C. berkeleyana.

Cosmospora viridescens (C. Booth) Gräfenhan & Seifert, comb. nov. MycoBank MB519432.
Basionym: Nectria viridescens C. Booth, Mycol. Papers 73: 89. 1959.

Typification: UK, England, Yorkshire, Sawley Woods, on black pyrenomycete on branches of Salix, Apr. 1954, C. Booth, holotype IMI 56736, isotype DAOM 83074.

Notes: The microconidial anamorph and teleomorph of this species as typified are described, illustrated, and discussed by Booth (1959) and Gams (1971).

Cosmospora viridescens is morphologically similar to C. vilior, but the latter has tuberculate ascospores, compared to the spinulose ascospores of C. viridescens (Samuels et al. 1990). Both species have Acremonium-like anamorphs with green colonies, and their perithecia occur on black, valsaceous stromata. Ascospore isolates made from perithecia collected on stromata of Hypoxylon and Ustulina in temperate areas often yield green colonies similar to C. viridescens, but are probably different from the tropical or subtropical species identified as C. vilior. Furthermore, differences in substrate specificity and geographic distribution support the distinction of C. viridescens from the other Cosmospora species mentioned above.

Cosmospora viridescens cannot be correlated with any described Acremonium species, nor can any of the described Acremonium species in this complex be unequivocally connected to any of the described teleomorphic species. Of the species in this complex with names based on anamorphic types, only C. arxii unequivocally has a known teleomorph, but it has apparently never been named.

Dialonectria (Sacc.) Cooke, Grevillea 12: 109. 1884. MycoBank MB1491.

Type species: Dialonectria episphaeria (Tode: Fr.) Cooke 1884 as D. sanguinea.

Stroma inconspicous or absent. Perithecia scattered and solitary or in small groups, pyriform with a short acute or round apical papilla, collapsing cupulate or pinched when dry, orange red to carmine red, turning dark red in KOH+, smooth-walled, usually < 200 μm high. Asci cylindrical to narrowly clavate, with an apical ring, 8 uniseriate ascospores. Ascospores hyaline to pale brown, 1-septate, smooth or becoming tuberculate when mature. Conidiophores initially as lateral phialides on somatic hyphae, sometimes verticillate, hyaline. Phialides monophialidic, subulate to subclavate, hyaline. Microconidia ellipsoidal to clavate, aseptate, hyaline, abundant. Macroconidia, if present, subcylindrical, moderately curved, slightly narrowing toward each end, apical cell often slightly hooked with a more or less pointed tip, basal cell not or scarcely pedicellate, predominantly 3–5-septate, hyaline, mostly thin-walled. Chlamydospores not observed.

Colonies on PDA slow growing, 25–50 mm diam in 14 d at room temperature, surface smooth, white to orange, aerial mycelium sparse, often becoming pionnotal, i.e. with abundant sporulation occuring in slimy masses over colony surface, often without discrete sporodochia.

Habitat: Mostly growing on stromata of other ascomycetes on deciduous trees.

Notes: Dialonectria was introduced first as a subgenus of Nectria and was revised in that context by Samuels et al. (1991), with a delimitation that more or less correlated with what the same authors later assigned to Cosmospora sensu Rossman. With the more restricted delimitation of Cosmospora adopted above, we also propose a restricted concept of Dialonectria around its type species, D. episphaeria. Most of the ~45 other species ascribed to Dialonectria by various authors have been reassigned or synonymised with other species by students of Nectria over the past 30 years.

Several phylogenetically distinct lineages are known within the D. episphaeria complex, one of which is described as a new species below.

Accepted species

Dialonectria episphaeria (Tode: Fr.) Cooke as D. sanguinea, Grevillea 12: 110. 1884.
Basionym: Sphaeria episphaeria Tode: Fr., Tode, Fungi Mecklenb. Sel. 2: 21. 1791: Fries, Syst. Mycol. 2: 454. 1823.

• ≡ Nectria episphaeria (Tode: Fr.) Fr., Summa Veg. Scand. 2: 388. 1846.

• ≡ Cucurbitaria episphaeria (Tode: Fr.) O. Kuntze, Rev. Gen. Plant. 3: 461. 1898.

• ≡ Fusarium episphaeria (Tode) W.C. Snyder & H.N. Hansen, Amer. J. Bot. 32: 662. 1945.

• ≡ Cosmospora episphaeria (Tode: Fr.) Rossman & Samuels in Rossman, Samuels, Rogerson & Lowen, Stud. Mycol. 42: 121. 1999.

Typification: Origin unknown, lectotype designated by Booth (1959) in L 0112704, Herb. Lugd. Bat. 910267659 ex Herb. Persoon, isotype TNS.

Notes: For description, illustrations, and discussion of the teleomorph, see Booth (1959). The anamorph produces micro- and macroconidia and is described by Gerlach & Nirenberg (1982) and Nelson et al. (1983).

The morphological species Dialonectria episphaeria splits into at least five phylogenetic lineages, which share similar phenotypic traits (Gräfenhan et al. 2008). There is presently no fresh, well-characterised material on Diatrype on Crataegus from northern Germany suitable for epitypification. The anamorph of D. episphaeria was often reported as or referred to as Fusarium aquaeductuum var. medium, e.g. Gerlach & Nirenberg 1982, but we consider this to represent a different phylogenetic species that is described below as a new species.

Dialonectria ullevolea Seifert & Gräfenhan, sp. nov. MycoBank MB519433. Fig. 3A–J.

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Fig. 3.

A–J. Dialonectria ullevolea, ex-type strain (BBA 64549). A. Micro- and macroconidia formed on CMA after 18 d. B. Colony surface on PDA after 1 mo. C. Microconidia formed on CMA after 18 d. D–E. Phialides bearing microconidia on agar surface (D) and submerged (E) on CMA after 14 d. F. Cylindrical asci with obliquely uniseriate ascospores. G. Pyriform perithecia in culture on CMA after 50 d. H. Cells at surface of perithecial wall mounted in water. I. Perithecial apex mounted in water. J. Ascospores in optical section mounted in water. Scale bars: C, D, E, J = 10 μm; A, F, H, I = 20 μm; G = 200 μm.

• = Fusarium aquaeductuum var. medium Wollenw., Fus. autogr. del., no. 844. 1930.

Etymology: K.A.S. recalls impassioned discussion on the topic of dividing Fusarium with P. Crous, K. O'Donnell, M. Stadler, and B. Summerell during the 7^th International Mycological Congress in Oslo, Norway, August 2002; this is commemorated with Dialonectria ullevolea, named for the Ullevol pub, where this discussion occurred.

Coloniae in agaro CMA perithecia fertilia, aurantiaco-rubra vel rubra formantes; perithecia pyriformia, papilla brevi praedita, Dialonectriae episphaeriae similia, ascosporis dilute brunneis, bicellularibus, (8.7–)9.7–11(–12.5) × (3.7–)4–4.5(–4.8) μm. Conidiophora primum phialides simplices ex hyphis orientes, deinde irregulariter ramosa, nonnumquam verticillata. Monophialides subulatae vel subclavatae, 8–20 × 1.5–2.3 μm. Conidia copiosa in pionnote conidiophororum aggregatorum vel in conidiophoris singulis, tenuitunicata, hyalina: microconidia ellipsoidea vel clavata, unicellularia, (3–)3.5–5(–6.5) × 1–1.5(–1.7) μm, fere copiosa; macroconidia plerumque 3–5-septata, 1-septata: 10–25 × 1.5–2 μm, 3-septata: (20–)30–42(–48) × (1.8-)2–2.5(–2.7) μm, 4–5-septata: (30–)37–43.5(–50) × (1.8-)2–2.5(–2.7) μm, 6–7-septata: 40–48(–52) × (2–)2.3–2.7 μm, subcylindrica, modice curvata, utrinque paulo angustata, sursum saepe paulo uncinata et plus minusve acutata; ad basim vix an non pedicellata. Coloniae in agaro PDA lente crescentes, 25–30 mm diam. post 14 dies, dilute aurantiae vel griseo-aurantiae. Mycelium aerium absens vel appressum, pionnotes aurantia iuxta coloniam mediam. Corpora sclerotialia absentia.

On CMA, the type culture forms fertile, orange red to bright red perithecia, pyriform each with a short apical papilla, morphologically similar to Dialonectria episphaeria as described by Booth (1959); ascospores pale brown, 1-septate, (8.7–)9.7–11(–12.5) × (3.7–) 4–4.5(–4.8) μm (n = 50).

Colonies slow-growing on PDA, 25–30 mm diam in 14 d at room temperature. Surface light orange (5A5) to greyish orange (5B5) in colony centre, whitish at margin, margin smooth to broadly lobed. Reverse similar in colour but less bright with a slightly yellowish tinge (6A4 to 6B5). Aerial mycelium sparse or occasionally with floccose spots, lacking or appressed at margin. Sporulation in orange pionnotal masses, first observed near colony centre. Sclerotial bodies not observed.

In culture on CMA: Conidiophores initially unbranched, with phialides arising laterally from hyphae, later irregularly or occasionally verticillately branched. Phialides monophialidic, subulate to subclavate, 8–20 × 1.5–2.3 μm, hyaline. Conidia produced abundantly in pionnotes of aggregated conidiophores or on single conidiophores, delicate, hyaline. Microconidia ellipsoidal to clavate, aseptate, (3–)3.5–5 (–6.5) × 1–1.5(–1.7) μm (n = 30), hyaline, abundant. Macroconidia subcylindrical, moderately curved, slightly narrowing toward each end, apical cell often slightly hooked with a more or less pointed tip; basal cell not or scarcely pedicellate, predominantly 3–5-septate, 1-septate: 10–25 × 1.5–2 μm (n = 5), 3-septate: (20–)30–42(–48) × (1.8-)2–2.5(–2.7) μm (n = 40), 4–5-septate: (30–)37–43.5(–50) × (1.8-)2–2.5(–2.7) μm (n = 30), 6–7-septate: 40–48(–52) × (2–)2.3–2.7 μm (n = 25). Chlamydospores not observed.

Typification: Netherlands, Baarn, Groeneveld, perithecia on branch of Fagus sylvatica, July 1984, K.A. Seifert 357, holotype CBS H-3565, ex-type cultures BBA 64549 = CBS 512.84 = NRRL 20688. GenBank barcodes: HQ897749 (rpb2), HQ897885 (acl1).

Other material examined: USA, Pennsylvania, near Salt Springs State Park, on pyrenomycete stroma on Fagus, May 2007, T. Gräfenhan 2007-56, DAOM 235827; Canada, Quebec, Mayo, Forêt la Blanche, on pyrenomycete stroma on deciduous tree, Oct. 2007, T. Gräfenhan 2007-72, DAOM 235828.

Notes: To preserve the taxonomic concept of F. aquaeductuum var. medium sensu Wollenweber (1930), we typify Dialonectria ullevolea with an isolate from Fagus sylvatica collected in The Netherlands. The species produces a teleomorph and both microconidial and macroconidial synanamorphs; it seems to be pan-temperate and has been collected in Europe and North America.

Fusicolla Bonord., Handbuch der allgemeinen Mykologie p. 150. 1851.

Type species: Fusicolla betae (Desm.) Bonord. 1851.

Stroma erumpent from host with hyphae forming a slimy, pale orange sheet over the substratum, with perithecia fully or partially immersed. Perithecia scattered to gregarious, or in small groups, globose to pyriform with a short acute or disk-like papilla, pinched when dry, yellow, pale buff to orange, KOH–, smooth walled, usually 100–200 μm high. Asci cylindrical to narrowly clavate, with an apical ring, 8 uniseriate ascospores. Ascospores hyaline to pale brown, 1-septate, smooth or becoming slightly verrucose when mature. Conidiophores initially as lateral phialides on somatic hyphae, sometimes monochasial, verticillate or penicillate, hyaline. Phialides monophialidic, cylindrical to subulate, hyaline. Microconidia sparse or absent, ellipsoidal to allantoid, aseptate, hyaline. Macroconidia falcate, more or less straight, or moderately to clearly curved, slightly narrowing toward each end, apical cell often hooked with a more or less pointed tip, basal cell slightly pedicellate, predominantly 1–3-septate, or 3–5-septate, in one species up to 10-septate, hyaline, mostly thin-walled. Chlamydospores absent, sparse, or abundant, when present globose, single, in pairs or chains, sometimes in macroconidia.

Colonies on PDA slow growing, 30–55 mm diam in 14 d at room temperature, surface smooth, whitish to pale brown, pink or orange, sometimes with violet or reddish-brown tones, often entirely pionnotal; aerial mycelium sparse or abundant, turf-like, felt-like, or coremioid if with violet or reddish-brown tones.

Habitat: On soil or plant matter in contact with soil, on woody material, slime flux of trees, sometimes on stromata of other fungi, in flowing water including drinking water and sewage.

Notes: Fusicolla has generally been considered a synonym of Fusarium (see notes under F. betae below), but is adopted here for elements of the F. aquaeductuum and F. merismoides species complexes. Some of the varieties attributed to those two species by other authors are raised to species rank. The application of the name Fusarium merismoides var. chlamydosporale remains uncertain at this time, while F. merismoides var. crassum is transferred to Atractium above.

Eight other species were described in Fusicolla before the genus was synonymised with Fusarium by Wollenweber (1916, see below), six of them by Karsten. We have not seen the type specimens of any of these species, which have apparently not been revised since their original descriptions.

Accepted species

Fusicolla betae (Desm.) Bonord., Handbuch der allgemeinen Mykologie p. 150. 1851. Fig. 4.
Basionym: Fusisporium betae Desm., Ann. Sci. Nat., Bot., Sér. 1, 19: 436. 1830.

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Fig. 4.

Fusicolla betae, lectotype (K). A. Sporodochium. B. Conidia and phialides. Scale bar in B = 10 μm.

• ≡ Fusarium betae (Desm.) Sacc., Michelia 2: 132. 1880.

• ≡ Pionnotes betae (Desm.) Sacc., Syll. Fung. 4: 726. 1886.

• ≡ Pionnotes rhizophila var. betae (Desm.) De Wild. & Durieu, Prodr. Fl. Belg. 2: 367. 1898.

Typification: France, on tuber of Beta vulgaris, spring 1826, Desmazières, lectotype designated here K(M) 167520, Plantes Cryptogames du Nord de la France, no. 305; epitype designated here: Germany, Schleswig-Holstein, Kiel, on young plants of Triticum aestivum, Jan. 1983, C. Bauers, preserved culture BBA 64317. GenBank barcodes: HQ897781 (rpb2), HQ897917 (acl1).

Other material identified: Germany, northern Germany, rotting potato tuber, E. Langerfeld DE 8, FRC E-0114 = MRC 2196 = NRRL 47186. Turkey, roots of Papaver, 2007, G. Turhan, T.G. 2007-70. UK, on Beta vulgaris, IMI 105043 = NRRL 22133.

Notes: Morphologically, Fusicolla betae closely resembles other members of the Fusicolla merismoides species complex, and critical taxonomic reevaluation of this complex is required to develop reliable species concepts.

There has been confusion over the identity of this species with two independent concepts in the literature. Wollenweber (1916, no. 99, 100) probably studied type material of Fusisporium betae, but later listed the species as synonym of Fusarium merismoides irrespective of precedence of the older species epithet (Wollenweber & Reinking 1935). Following this, the genus Fusicolla was usually listed as a synonym of Fusarium, e.g. Carmichael et al. 1980. Alternatively, Chupp (1954, p. 111) cited Fusarium betae and “Fusidium betae Desm.” (probably a lapsus for Fusisporium) as synonyms of Cercospora beticola. He cited only the type of C. beticola and types of other Cercospora names synonymised with C. beticola; types of the Fusarium/Fusidium names were not cited. We conjecture that he proposed the synonymy based on the identity of the host and a general congruence in conidial size and septation. Crous & Braun (2003) followed the latter synonymy including Fusisporium betae as a synonym of Cercospora apii s. lat.; they also did not see type material (U. Braun, pers. comm.). Our studies of the lectotype designated above confirm that Desmaziéres' fungus produces sporodochia, phialides, and Fusarium-like conidia identical to those of the epitype selected above.

Fusicolla acetilerea (Tubaki, C. Booth & T. Harada) Gräfenhan & Seifert, comb. et stat. nov. MycoBank MB519434.
Basionym: Fusarium merismoides var. acetilereum Tubaki, C. Booth & T. Harada, Trans. Brit. Mycol. Soc. 66: 355. 1976.

Typification: Japan, Osaka, near Osaka University, soil, 1973, T. Miyoshi, holotype IFO 30040, ex-type cultures IMI181488 = BBA 63789 = NRRL 20827. GenBank barcodes: HQ897701 (rpb2), HQ897839 (acl1).

Other material identified: Australia, soil, FRC E-0052 = NRRL 13261, FRC E-0120 = NRRL 47187, FRC E-0121 = NRRL 47188, ICMP 10485 = NRRL 39744, IMI 175962 = NRRL 22137. Philippines, Nueva Vizcaya, FRC E-0164 = NRRL 47201. south Africa, soil, FRC E-0130 = NRRL 47191, FRC E-0136 = NRRL 47193, FRC E-0205 = NRRL 47210, FRC E-0226 = NRRL 47215, FRC E-0229 = NRRL 47844, FRC E-0257 = NRRL 47222, FRC E-0265 = NRRL 47224, FRC E-0287 = NRRL 47231, FRC E-0288 = NRRL 47232. Zambia, soil, FRC E-0208 = NRRL 47212.

Notes: This species produces both macroconidia and microconidia. The holotype is described, illustrated, and discussed by Tubaki et al. (1976) and Gerlach & Nirenberg (1982).

Fusicolla aquaeductuum (Radlk. & Rabenh.) Gräfenhan, Seifert & Schroers, comb. nov. MycoBank MB519435.
Basionym: Selenosporium aquaeductuum Radlk. & Rabenh., Kunst-Gewerbe-Blatt 49: 10. 1863.

• ≡ Fusarium aquaeductuum (Radlk. & Rabenh.) Lagerh., Centralbl. Bakteriol. Parasitenk. 9: 655. 1891.

Typification: Germany, Bayern, München, water fountain near Gasteigberg, Nov. 1862, L. Radlkofer, lectotype designated here B 700014034. A permanent slide prepared by Radlkofer and sent to Wollenweber is selected here as the lectotype of Selenosporium aquaeductuum; it is the only known authentic material. epitype designated here: Germany, Berlin-Dahlem, Julius-Kühn-Institute (formerly BBA), isol. ex plugged water tap in BBA, May 1985, H.I. Nirenberg, ex-type cultures BBA 64559 = CBS 837.85 = NRRL 20865 = NRRL 37595. GenBank barcodes: HQ897744 (rpb2), HQ897880 (acl1).

Other material examined: Germany, Berlin, drinking water, 1974, W. Gerlach, BBA 63669 = CBS 734.79 = NRRL 20686; The Netherlands, Baarn, rubber tubing, 1953, A.L. van Beverwijk, CBS H-12677, CBS 268.53 = NRRL 22115.

Notes: No teleomorph is known for this species. For a description, illustrations, and discussion of the microconidial and macroconidial synanamorphs of this species as epitypified here, see Gerlach & Nirenberg (1982).

In Radlkofer (1863), two figures illustrate Selenosporium aquaeductuum, one showing 1–2(–4)-septate conidia borne on phialides. Wollenweber (1916) studied a permanent slide originally prepared by Radlkofer and drew the fungus with 1-septate and 3–4-septate conidia. On the herbarium sheet with that slide, Wollenweber noted the presence of two Fusarium species, F. aquaeductuum with 1-septate conidia, 18–22 × 1.5–2 μm and F. biasolettianum with 3-septate conidia, 30–55 × 2–2.5 μm. Based on similarities of the phenotype and substrate preferences, we classify Fusarium aquaeductuum in Fusicolla.

Wollenweber & Reinking (1935) included Microcera brachyspora Sacc. & Scalia as a synonym of F. aquaeductuum, but this should be confirmed with type studies.

Wollenweber (1931) linked Fusarium aquaeductuum var. aquaeductuum to “Nectria” episphaeria var. coronata (syn. “Nectria” purtonii, see below); subsequently this anamorph-teleomorph connection was accepted by Booth (1959), Gerlach and Nirenberg (1982), Samuels et al. (1991), and Rossman et al. (1999). According to our phylogenetic results, “Nectria” purtonii is not a member of Fusicolla but belongs to Stylonectria. The reported anamorph-teleomorph connection could not be confirmed here.

Fusicolla epistroma (Höhn.) Gräfenhan & Seifert, comb. nov. MycoBank MB519436.
Basionym: Dendrodochium epistroma Höhn., Sitzungsber. Kaiserl. Akad. Wiss., Wien, Math.-Naturwiss. Kl., Abt. 1, 118: 424. 1909.

• ≡ Fusarium epistroma (Höhn.) C. Booth as F. epistromum, The Genus Fusarium p. 66. 1971.

Typification: Germany, Brandenburg, “Schmidt's Grund” near Tamsel, on old stromata of Diatrypella favacea on branches of Betula, Nov. 1906, P. Vogel, Sydow's Mycotheca germanica 648 Hymenula epistroma, lectotype B 700014042 designated here, isotypes FH 00286649, K, S F40143. epitype designated here: UK, England, Yorkshire, Aberford & Gundale, on Diatrypella on Betula, Apr. 1961, C. Booth, IMI 85601, ex-type cultures ATCC 24369 = BBA 62201 = NRRL 20461 = NRRL 20439. GenBank barcodes: HQ897765 (rpb2), HQ897901 (acl1).

Other material examined: Germany, Triglitz, 1907, O. Jaap, herb. von Höhnel 3087, FH 00286650.

Notes: For descriptions, illustrations, and discussion of the micro- and macroconidial synanamorphs of this species, see Booth (1971) and Gerlach & Nirenberg (1982).

An anamorph-teleomorph connection of F. epistromum with Nectria (“Cosmospora“) magnusiana was suggested by Höhnel (1909) and later followed by Jaap (1910), Booth (1959), Gerlach & Nirenberg (1982), and Samuels et al. (1991). Höhnel (1909) based his assumption on the observation that both fungi occurred on the same host fungus, Diatrypella favacea. However, he did not collect or observe the teleomorph together with his Dendrodochium epistroma. Wollenweber (1924, No. 539) studied a specimen of N. magnusiana collected by Jaap (Fungi selecti exs. 418) and questioned the link with Höhnel's anamorphic fungus. Booth's (1959) report of the anamorph-teleomorph connection included a drawing of the anamorph that lacks attribution to a specimen, but looks much like Wollenweber's Fusaria autographice delineata no. 539. The conidiophores and conidia are similar, having subulate phialides and non-septate, oblong to allantoid conidia. We compared Rehm's type material (S F84956, B 700014041) to the description given by Samuels et al. (1991) based on Jaap's exsiccati. In contrast to the latter, the KOH–ascomatal wall of the type specimen appears slightly verrucose and the colour is dark orange-brown with an obtuse apex and an ostiolar area that becomes almost black. Mature ascospores of Nectria magnusiana measure (12–)13–14.5(–15.5) × (5.5–)5.8–6.5(–6.8) μm and are significantly wider than those of the Jaap exsiccata studied by Samuels et al. (1991). The type material of N. magnusiana is reminiscent of Neonectria or Nectria s.str. An anamorph was associated with the same stroma from which perithecia developed. Its buff-coloured hymenium bears oblong-ellipsoidal microconidia conidia, 3.5–8 × 1–2 μm. These microconidia match those observed in two authentic collections of Dendrodochium epistroma (Sydow's Mycotheca Germanica 648 and Jaap's Fungi Selecti Exsiccati 349). Booth (1959) and Samuels et al. (1991) concluded that D. epistroma is the anamorph of N. magnusiana, both being host specific to Diatrypella favacea. Only a few Fusarium-like macroconidia were found on the type material of Dendrodochium epistroma, but macroconidia were lacking on the hymenium of the type collection of N. magnusiana. Interestingly, in culture the ex-type isolate of Fusicolla epistroma produces predominantly 3-septate conidia, rarely microconidia. From this, it remains unclear whether the associated anamorph on the type material of N. magnusiana is Fusicolla epistroma. Therefore, we decided to designate the epitype for F. epistroma based on Booth's material and not to consider the older species name Nectria magnusiana for this species.

Fusicolla matuoi (Hosoya & Tubaki) Gräfenhan & Seifert, comb. nov. MycoBank MB519437.
Basionym: Fusarium matuoi Hosoya & Tubaki, Mycoscience 45: 264. 2004.

• ≡ Cosmospora matuoi Hosoya & Tubaki, Mycoscience 45: 262. 2004.

• [= Fusarium splendens Matuo & Takah. Kobay., nom. nud., Trans. Mycol. Soc. Japan 2(4): 13. 1960].

Typification: Japan, Honshu, Yamagata Pref., Mamurogawa-machi, Mogami-gun, on Albizia julibrissin, Oct. 1958, T. Kobayashi, holotype TNS F-11127, ex-type culture MAFF 410976.

Other material examined: Iran, Prov. Gilan, near Bandarepahlavi, on rotting stalk of Zea mays, Oct. 1968, D. Ershad, BBA 62154 = FRC E-0089 = NRRL 47180. Japan, on Albizia julibrissin, Oct. 1959, T. Kobayashi, ATCC 18694 = CBS 581.78 = MAFF 238445 = NRRL 20427.

Notes: For a description, illustrations, and discussion of the teleomorph and micro- and macroconidial synanamorphs of this species, see Hosoya & Tubaki (2004).

Fusicolla merismoides (Corda) Gräfenhan, Seifert & Schroers, comb. nov. MycoBank MB519438.
Basionym: Fusarium merismoides Corda, Icon. Fung. 2: 4. 1838.

Typification: Czech Republic, Prague, on very wet shards of a plant pot, winter 1836, Corda, holotype PRM 155493.

Notes: Fusicolla merismoides is morphologically well characterised and has been widely accepted as a distinctive species (Wollenweber 1931, Booth 1971, Gerlach & Nirenberg 1982, Nelson et al. 1983, Leslie et al. 2006, Domsch et al. 2007); these authors provide descriptions, illustrations, and discussion of the macroconidial anamorph of this species. The morphological species concept was established by Wollenweber & Reinking (1935), who synonymised numerous taxa with Fusarium merismoides var. merismoides. Unlike F. betae, which is mainly known from roots and tubers of plants, F. merismoides is commonly isolated from soils, polluted water, slime fluxes of trees, rotting plant material, and many other substrates. Gräfenhan et al. (2008) discovered several phylogenetic lineages in the F. merismoides morphological species, including some ascospore isolates; the same conclusion can be drawn from publically available sequences attached to this name. We studied Corda's type material deposited in PRM and could not come to a satisfying conclusion on the selection of an appropriate epitype based solely on the macroconidial characteristics. Moreover, after examination of authentic material of Fusarium biasolettianum (PRM 155487), we could not confirm the reported synomymy with Fusicolla merismoides (Wollenweber & Reinking 1935). Macroconidia of Fusarium biasolettianum have almost an pointed and slightly hooked apical cell and a pedicellate basal cell (Fig. 5) that rather resemble macroconidium characteristics of Fusarium s. str. species. Rossman et al. (1999) mentioned Chrysogluten biasolettianum nom. rej., but there is no nomenclatural connection between this teleomorphic fungus and F. biasolettianum; the coincidental epithets indicate only that they were named in honour of the Italian botanist B. Biasoletto.

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Fig. 5.

Fusarium biasolettianum, authentic material (PRM 155487). Macroconidia. Scale bar = 10 μm.

Most of the varieties within F. merismoides are distinct species, either within Fusicolla or in sister genera.

Fusicolla violacea Gräfenhan & Seifert, sp. nov. MycoBank MB519439.

• = Fusarium merismoides var. violaceum W. Gerlach, Phytopathol. Z. 90: 34. 1977. nom. inval. Art. 37.

Latin description in Gerlach, Phytopath. Z. 90: 34-35. 1977 under the name “Fusarium merismoides var. violaceum“.

Typification: Iran, Prov. Gilan, near Rasht, on Quadraspidiotus perniciosus (San José insect) scaleon dying twig of Prunus domestica, Nov. 1968, W. Klett, holotype CBS 634.76, permanently cryopreserved culture, ex-type cultures BBA 62461 = NRRL 20896. GenBank barcodes: HQ897696 (rpb2).

Notes: For descriptions, illustrations, and discussion of the micro- and macroconidial synanamorphs of this species, see Gerlach (1977) and Gerlach & Nirenberg (1982).

The taxon was not validly published because the author did not designate a holotype, instead listing one living strain with accession numbers in two culture collections as “Cultura typica”.

Macroconia (Wollenw.) Gräfenhan, Seifert & Schroers, gen. et stat. nov. MycoBank MB519441.
Basionym: Nectria sect. Macroconia Wollenw., Angew. Bot. 8: 179. 1926. MycoBank MB519440.

Type species: Nectria leptosphaeriae Niessl in Krieger 1886, here recognised as Macroconia leptosphaeriae (Niessl) Gräfenhan & Schroers.

Stroma inconspicous or absent. Perithecia solitary, subglobose with or without a small apical papilla, collapsing cupulate when dry, orange to carmine red, KOH+ dark red to violet, sometimes with hyphal hairs arising from outer wall, usually 100–250 μm high. Asci cylindrical to narrowly clavate, with a simple apex, 8 uniseriate to partially biseriate ascospores. Ascospores yellowish, 1-septate, smooth or becoming striate when mature. Conidiophores initially as lateral phialides on somatic hyphae, later monochasial to verticillate, hyaline. Phialides monophialidic, cylindrical to subulate, hyaline. Microconidia absent or very rare, when present ellipsoidal to allantoid, hyaline. Macroconidia robust, subcylindrical to moderately curved, apical cell conical or hooked, basal cell mostly conspicuously pedicellate, 3–7(–14)-septate, hyaline, mostly thick-walled. Chlamydospores absent or rare, when present globose, single, in pairs, or in chains in hyphae.

Colonies on PDA slow- or very slow-growing, 7–10 or ~ 45 mm diam in 14 d at room temperature, whitish to orange or reddish brown; aerial mycelium abundant, with discrete pink, orange or reddish brown sporodochia or small pionnotes.

Habitat: Mostly growing on stromata of other ascomycetes on herbaceous plants or deciduous trees.

Notes: Based on the section name originally in Nectria (Wollenweber 1926), but also used as a “Gruppe” in Fusarium (Wollenweber & Reinking 1935), we raise Macroconia to generic rank here for five species with large Fusarium-like macroconidia and minute perithecia.

Accepted species

Microcera coccophila Desm., Ann. Sci. Nat., Bot., Sér. 3, 10: 359. 1848. Fig. 7A, B.
Basionym: Tubercularia coccophila (Desm.) Bonord., Abh. Geb. Mykol., p. 96. 1864.

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Fig. 7.

Two Microcera species. A, B. Microcera coccophila. A. Habit, with conical red perithecia on a stroma growing over scale insect and flame-like synnema emerging from the top. B. Macroconidia. C, D. M. larvarum. C. Flame-like conidiomata on scale insect. D. Conidia. Scale bars = 10 μm.

• ≡ Fusarium coccophilum (Desm.) Wollenw. & Reinking, Die Fusarien, p. 34. 1935.

• ≡ Fusarium episphaeria f. coccophilum (Desm.) W.C. Snyder & H.N. Hansen, Amer. J. Bot. 32: 662. 1945.

• = Microcera pluriseptata Cooke & Massee in Cooke, Grevillea 17: 43. 1888.

Typification: France, Normandy, near Caen, on Eulecanium tiliae (nut scale) on living and young trunks of Salix and Fraxinus excelsior, Feb. 1847, M. Roberge, lectotype designated here K (M) 165807, Plantes Cryptogames de France, Ed. II, Ser. I, No. 1350, isotypes P, K (M) 165806, Plantes Cryptogames de France Ed. I, Ser. I, No. 1750.

Additional material examined: Japan, Saitama, Hiki-gun, Ogawa-machi, on scale insect on Broussonetia kazinoki × B. papryifera, Jul. 1993, G. Okada.

Notes: The macroconidial anamorph and the teleomorph of this species as lectotypified here is described and discussed in detail by Petch (1921). For description, illustrations, and further taxonomic synonyms of the anamorph, see Gerlach & Nirenberg (1982).

There has been confusion about synonymies and anamorph-teleomorph connections between this fungus, M. diploa, and M. larvarum. Petch (1921) synonymised the anamorphic name Atractium flammeum Berk. & Ravenel with Microcera coccophila, arguing that Sphaerostilbe flammea Tul. & C. Tul. represented the holomorph of M. coccophila and that Sphaerostilbe coccophila Tul. & C. Tul. was actually a different species, M. larvarum (as “Nectria” aurantiicola). He cited two Desmazières exsiccati of M. coccophila, namely Plantes Cryptogames de France, Ed. I, Ser. I, No. 1750 and ibid. Ed. II, Ser. I, No. 1350. Our reexamination of the latter confirms Petch's observation that mature perithecia have 1-septate ascospores, 12–18 × 5–7 μm, associated with the anamorph. “Nectria” flammea reportedly has larger ascospores (Dingley 1951, 15–24 × 6–10 μm; Booth 1971, 1981b, 16–20 × 7.5–10 μm). The anamorph-teleomorph connection of Microcera coccophila with “Nectria” flammea needs to be critically reevaluated.

Gräfenhan et al. (2008) noted the occurrence of several phylogenetic species among anamorph and teleomorph collections that are morphologically similar to M. coccophila, M. diploa, and M. larvarum.

Microcera diploa (Berk. & M.A. Curtis) Gräfenhan & Seifert, comb. nov. MycoBank MB519448.
Basionym: Nectria diploa Berk. & M.A. Curtis, J. Linn. Soc., Bot. 10: 378. 1869.

• ≡ Cucurbitaria diploa (Berk. & M.A. Curtis) O. Kuntze, Rev. Gen. Plant. 3: 461. 1898.

• ≡ Creonectria diploa (Berk. & M.A. Curtis) Seaver, Mycologia 1: 190. 1909.

• ≡ Calonectria diploa (Berk. & M.A. Curtis) Wollenw., Angew. Bot. 8: 193. 1926.

• ≡ Cosmospora diploa (Berk. & M.A. Curtis) Rossman & Samuels in Rossman, Samuels, Rogerson & Lowen, Stud. Mycol. 42: 121. 1999.

• = Fusarium coccidicola Henn. [as “coccideicola”], Bot. Jahrb. Syst. 34: 57. 1904.

• = Aschersonia henningsii Koord., Bot. Untersuch. Java p. 213. 1907.

• ≡ Microcera henningsii (Koord.) Petch, Ann. Roy. Bot. Gard. Peradeniya 5: 533. 1914.

• ≡ Pseudomicrocera henningsii (Koord.) Petch, Trans. Brit. Mycol. Soc. 7: 164. 1921.

• = Microcera fujikuroi Miyabe & Sawada, J. Coll. Agric. Tohoku Imp. Univ. 5: 83. 1913.

• = Microcera merrillii Syd., Ann. Mycol. 12: 576. 1914.

Typification: Cuba, on individual scale insects on bark, C. Wright 606 ex Herb. Berk., Fungi Cubensis Wrightiana 767, lectotype K designated by Booth 1971, isotypes FH 00286651, FH 00286652, NYS.

Notes: The holotype of this species is consistent with the descriptions of the teleomorph by Booth (1971) and Rossman (1983). The macroconidial anamorph is described by Booth (1971), Gerlach & Nirenberg (1982), and Rossman (1983). As explained in the introduction, under the present Art. 59, the proposed new combination results in a technically incorrect but valid and legitimate name.

Microcera diploa is an entomogenous species reported from many tropical and subtropical regions (Booth 1971, Rossman 1983), commonly found on various scale insects sitting on several plant species. Booth (1971) studied the type collection and reported pustules of perithecia on a stroma associated with the anamorph. From our observations of the same material, it is clear that the stromata developed over individual scale insects. In agreement with Rossman (1983), we follow Booth's decision to interpret the Cuban specimen as the type of Nectria diploa. Several Fusarium species were synonymised with M. diploa, namely F. derridis, F. juruanum, and F. pentaclethrae, which were described only from herbaceous material (Wollenweber & Reinking 1935). We studied Hennings' material (F. derridis = B 700014017; F. juruanum = B 700014035, B 700014036; F. pentaclethrae = B 700014037), and none seem to be insect-associated. Therefore, we reject these synonymies, except for F. coccidicola as listed above.

Microcera larvarum (Fuckel) Gräfenhan, Seifert & Schroers, comb. nov. MycoBank MB519449. Fig. 7C, D.
Basionym: Fusarium larvarum Fuckel, Jahrb. Nassauischen Vereins Naturk. 23–24: 369. 1870.

• = Microcera parlatoriaeTrab., Bull. Agric. Algérie Tunisie 13: 33. 1907.

• = Microcera curta Sacc., Ann. Mycol. 7: 437. 1909.

• = Microcera tonduzii Pat., Bull. Soc. Mycol. France 28: 142. 1912.

• = Microcera aurantiicola Petch, Trans. Brit. Mycol. Soc. 7: 163. 1921.

Typification: Germany, Hessen, Rheingau, near Oestrich-Winkel, on larva cuticles of insects on apple trees, in spring, L. Fuckel, lectotype designated here G 00111015 epitype designated here: Iran, Prov. Gilan, near Rasht, on Quadraspidiotus perniciosus (San José insect) scale on Prunus domestica, Oct. 1968, W. Gerlach & D. Ershad, epitype BBA, ex-type cultures BBA 62239 = CBS 738.79 = MUCL 19033 = NRRL 20473. GenBank barcodes: HQ897768 (rpb2), HQ897904 (acl1).

Notes: For descriptions, illustrations, and further taxonomic synonyms of the teleomorph and macroconidial anamorph of this species, see Petch (1921), Wollenweber (1931), Booth (1971, 1981a, c), and Gerlach & Nirenberg (1982).

Our phylogenetic analysis and that of Bills et al. (2009) clearly indicate that the two varieties of M. larvarum segregated by Gerlach (1977) warrant species rank; M. larvarum var. rubrum is recognised as a distinct species below. Bills et al. (2009) studied parnafungin production by species of this complex, and their data suggest that perhaps two additional phylogenetic species may exist in this group.

The synonymy of Microcera larvarum with “Nectria” aurantiicola cited by Booth (1971, 1981a), Gerlach & Nirenberg (1982), and Rossman et al. (1999) should be critically reviewed.

Microcera rubra Gräfenhan & Seifert, sp. nov. MycoBank MB519450.

• = Fusarium larvarum var. rubrum W. Gerlach, Phytopath. Z. 90: 38. 1977. nom. inval. Art. 37.

Latin description in Gerlach, Phytopath. Z. 90: 38. 1977 under the name “Fusarium” larvarum var. rubrum.

Typification: Iran, Prov. Gilan, near Rasht, on Quadraspidiotus perniciosus (San José insect) scale on Prunus domestica, Oct. 1968, W. Gerlach & D. Ershad, holotype CBS H-714, ex-type cultures BBA 62460 = CBS 638.76 = NRRL 20475 = NRRL 22111 = NRRL 22170. GenBank barcodes: HQ897767 (rpb2), HQ897903 (acl1).

Notes: For descriptions, illustrations, and discussion of this macroconidial species, see Gerlach (1977) and Gerlach & Nirenberg (1982); for phylogenetic relationships, see Bills et al. (2009).

The taxon was not validly published because the author did not designate a holotype, instead listing one living strain with accession numbers in two culture collections as “Cultura typica”.

Pseudonectria Seaver, Mycologia 1: 48. 1909.

Type species: Pseudonectria rousseliana (Mont.) Clements & Shear 1931, here recognised as P. buxi (DC.) Seifert, Gräfenhan & Schroers.

Notes: Pseudonectria as presently circumscribed is not monophyletic (Fig. 1), with two species branching out in separate clades in the Nectriaceae. The type species of Pseudonectria, together with an undescribed taxon, forms a sister clade to Atractium. The second species, “Pseudonectria” pachysandricola together with “Nectria” diminuta and “N.” rubropeziza, falls between the terminal and basal Fusarium-like clade. Therefore, only one species is presently recognised in this genus, with the teleomorph typifying the oldest available generic name Pseudonectria 1909, and the anamorph representing the type of the later generic name Chaetodochium 1932. There is presently no acceptable generic name for “Pseudonectria” pachysandricola, which is well described and illustrated by Dodge (1944) and Rossman et al. (1993).

The anamorphs of Pseudonectria are fairly well understood pathogens on the Buxaceae (Bezerra 1963, Rossman et al. 1993), but these species are usually cited under their anamorph names, i.e. “Volutella” buxi and “V.” pachysandricola. Because these species do not share common morphological characters with Volutella s. str. (see below) and are phylogenetically distinct, these anamorph names should not be used. The phylogenetic relationship of a biologically and morphologically similar species described from Ruscus aculeatus, “V.” rusci, remains unresolved.

Pseudonectria buxi (DC.) Seifert, Gräfenhan & Schroers, comb. nov. MycoBank MB519451.
Basionym: Tubercularia buxi DC., Flore française, Edn. 3 (Paris) 6: 110. 1815.

• ≡ Chaetostroma buxi (DC.) Corda, Icon. Fung. 2: 30. 1838.

• ≡ Volutella buxi (DC.) Berk., Outl. Brit. Fungi p. 340. 1860.

• ≡ Chaetodochium buxi (DC.) Höhn., Mitt. bot. Inst. tech. Hochsch. Wien 9: 45. 1932.

• = Pseudonectria rousseliana (Mont.) Clements & Shear, Genera of Fungi p. 280. 1931.

• ≡ Nectria rousseliana Mont. in Castagne, Cat. P1. Marseille Suppl. p. 44. 1851. For additional obligate synonyms, see Rossman et al. 1993.

Notes: Bezerra (1963) and Rossman et al. (1993) redescribed and illustrated both the anamorph and teleomorph of P. buxi, a common pathogen of Buxus sempervirens. The conidia of the anamorph tend toward fusiform, a shape not seen in species of Volutella s. str., and the sporodochia tend to be broadly attached to the substratum. These are subtle characters, and at present we cannot suggest robust morphological characters to unequivocally distinguish the anamorphs of Pseudonectria from Volutella. However, the teleomorphs are rather different, with the perithecia of Volutella being red and those of Pseudonectria being green.

Because this fungus has a known teleomorph and anamorph, Art. 59 applies, and our transfer of an anamorphically typified epithet to a teleomorphically typified generic name is technically incorrect according to the present ICBN, but it is valid and legitimate.

StylonectriaHöhn., Sitzungsber. Kaiserl. Akad. Wiss., Wien, Math.-Naturwiss. Kl., Abt. 1, 124: 52. 1915.

Type species: Stylonectria applanata Höhn. 1915.

Stroma thin, whitish or yellow, hyphal or subiculum-like. Perithecia gregarious in groups of up to 20, subglobose, pyriform to subcylindrical, with a rounded or broad, circular, flat disc on a venter-like neck, sometimes laterally collapsing when dry, pale yellow, orange-red, orange-brown, or pale to dark red, KOH+ dark red to purple, yellow in lactic acid, smooth, usually shiny, slightly iridescent, 150–250(–350) μm high. Perithecial wall consisting of two regions: inner region of hyaline, thin-walled, compressed, elongate cells; outer region of distinct, isodiametric to oblong, angular or globose, thick-walled cells. Asci cylindrical to clavate, apex simple or with a ring, with 8 uniseriate, biseriate or irregularly disposed ascospores. Ascospores hyaline or yellow to pale brown, 1-septate, cylindrical to allantoid or ellipsoidal, smooth or tuberculate, generally thick-walled. Conidiophores initially formed mostly as unbranched phialides on somatic hyphae, occasionally loosely branched, sometimes forming small sporodochia. Phialides monophialidic, almost cylindrical to subcylindrical, often with a distinct collarette. Microconidia sparsely produced, allantoid to lunulate, slightly to strongly curved, aseptate, in slimy heads. Macroconidia orange in mass, subcylindrical or moderately to strongly curved, falcate, mostly 0–1-septate, apex narrower than base, apical cell blunt or hooked, basal cell not or scarcely pedicellate. Chlamydospores not observed.

In culture on PDA slow- to very slow-growing, 10–30 mm diam in 14 d at room temperature, surface white, later becoming off-white to pale or bright orange, occasionally with orange sporodochia; aerial mycelium mostly lacking, if present, sparse and appressed margin smooth to broadly lobed

Habitat: Restricted to stromata of ascomycetes, mainly in the Diaporthales.

Notes: Stylonectria was described by Höhnel (1915) as an anamorph genus with the type and only species, S. applanata, for which the teleomorph was considered to be “Nectria” applanata var. succinea. Booth (1959) presented convincing evidence that Höhnel (1915) actually was dealing with a teleomorphic fungus, which was further explained by Rossman et al. (1999). Species of Stylonectria are considered to be host specific, probably to the fungal host, which itself may be host specific to the plant.

Accepted species

Stylonectria applanata Höhn., Sitzungsber. Kaiserl. Akad. Wiss., Wien, Math.-Naturwiss. Kl., Abt. 1, 124: 52. 1915.

• = Nectria applanata var. succinea Höhn., Sitzungsber. Kaiserl. Akad. Wiss., Wien, Math.-Naturwiss. Kl., Abt. 1, 124: 51. 1915.

Typification: Austria, Niederösterreich, near Sonntagsberg, on stromata of Melogramma bulliardii on dead twigs of Corylus avellana, Aug. 1914, P. Strasser, lectotype designated here FH 00286663.

Notes: For descriptions and discussion of the teleomorph, microconidial anamorph, and macroconidial synanamorph of this species, see von Höhnel (1915) and Weese (1916).

Von Höhnel (1915) distinguished “Nectria” applanata var. succinea from “N.” applanata var. applanata based on the pale yellow colour of the translucent perithecia. Otherwise, the two varieties were described with identical macro- and microscopic characters. Because host specificity is an important character for distinguishing species of Stylonectria (cf. Gräfenhan 2009), we recognise S. applanata as a distinct species from S. carpini, described below, i.e. Nectria applanata var. applanata.

Stylonectria carpini Gräfenhan, nom. nov. MycoBank MB519452.

• ≡ Nectria applanata Fuckel, Jahrb. Nassauischen Vereins Naturk. 25–26: 310. 1871 (1872).

• ≡ Cucurbitaria applanata (Fuckel) O. Kuntze, Rev. Gen. Plant. 3: 460. 1898.

• ≡ Dialonectria applanata (Fuckel) Petch, Trans. Brit. Mycol. Soc. 25: 170. 1941.

Etymology: The species epithet is derived from the plant host genus Carpinus.

Typification: Germany, Hessen, Rheingau, Aepfelbach im Oestricherwald, on black pyrenomycete on decaying, corticated branches of Carpinus betulus, L. Fuckel, Fuckel Fungi Rhenani 2356, lectotype designated here G 00111018, isotypes B 700014054, FH 00286648, K, DAOM 119800 = Herb. Barbey-Boissier 862.

Other material examined: Austria, Niederösterreich, Gießhübl, Wasserspreng, Talgrund, (Finsterer Gang), MTB 7863/1, on Melanconis spodiaea on Carpinus betulus, Aug. 2006, H. Voglmayr W.J. 3013, DAOM 235819. Germany, Schleswig-Holstein, near Stegelkamp, Naturwaldzelle Endern, on pyrenomycete on Carpinus betulus, Aug. 2008, T. Gräfenhan 2008-17, DAOM 235829.

Notes: This species produces both a micro- and a macroconidial synanamorph in addition to a teleomorph. Our examination of Höhnel's type material of Stylonectria applanata (FH 00286663) and that of Fuckel's “Nectria” applanata (G 00111018) suggests the two species are not conspecific, but both are species of Stylonectria; the latter is therefore renamed here.

The distribution of Stylonectria carpini corresponds to the distribution of Carpinus betulinus in Europe. In North America, a different species of Stylonectria occurs on a black pyrenomycete on the congeneric native host, Carpinus caroliniana, and has a microconidial anamorph in culture and a distinctly different teleomorph. Collections made from a pyrenomycete on Betula are morphologically similar to S. carpini but phylogenetically distinct.

Stylonectria purtonii (Grev.) Gräfenhan, comb. nov. MycoBank MB519453.
Basionym: Sphaeria purtonii Grev., Scot. Crypt. Fl. 6: 23. 1828.

• ≡ Nectria purtonii (Grev.) Berk., Outl. Brit. Fung. p. 394. 1860.

• ≡ Dialonectria purtonii (Grev.) Cooke, Grevillea 12: 110. 1884.

• ≡ Cucurbitaria purtonii (Grev.) O. Kuntze, Rev. Gen. Plant. 3: 461. 1898.

• ≡ Cosmospora purtonii (Grev.) Rossman & Samuels in Rossman, Samuels, Rogerson & Lowen, Stud. Mycol. 42: 124. 1999.

Typification: UK, Scotland, Edinburgh, Rosslyn Woods, on black pyrenomycete on small branches of coniferous tree, 1820, Greville, lectotype E designated by Booth 1958.

Other material examined: France, Provence, St. Remy, on old stromata of pyrenomycete on Coronilla emerus, Oct. 1974, W. Gams, culture CBS 717.74. Germany, Nordrhein-Westfalen, Detmold, Externsteine, on small branches of felled trees of Picea abies, Apr. 2007, T. Gräfenhan 2007-30, DAOM 235818.

Notes: For descriptions, illustrations, and further taxonomic synonyms of the teleomorph as well as microconidial and macroconidial synanamorphs of this species, see Booth (1959) and Samuels (1976).

Stylonectria wegeliniana (Rehm) Gräfenhan, Voglmayr & Jaklitsch, comb. nov. MycoBank MB519454.
Basionym: Nectria episphaeria var. wegeliniana Rehm, Hewigia 30: 260. 1891.

• ≡ Dialonectria wegeliniana (Rehm) Petch, Trans. Brit. Mycol. Soc. 21: 266. 1938 as D. wegeliana.

• ≡ Cosmospora wegeliniana (Rehm) Rossman & Samuels in Rossman, Samuels, Rogerson & Lowen, Stud. Mycol. 42: 131. 1999.

Typification: switzerland, Heimiswyl bridge near Bern, on Hapalocystis bicaudata (= Pseudovalsa berkeleyi) on dry branches of Ulmus, Oct. 1887, Wegelin, Rehm Ascomyceten 1045, lectotype designated here S F86597, isotypeNY.

Other material examined: Austria, Niederösterreich, Distr. Mödling, Comm. Hinterbrühl, Wassergspreng, Finsterer Gang west of Gießhübl, margin of a forest road, elev. 400 m, map grid 7863/3, on Hapalocystis bicaudata on corticated dead branches of Ulmus glabra attached to the living tree, May 2009, H. Voglmayr, WU 29855, culture CBS 125490.

Notes: This species produces microconidia and macroconidia in culture; the teleomorph was only found in nature. For a description, illustrations, and discussion of the species, see Weese (1916).

Volutella Tode 1790: Fr. 1832. Fungi Mecklenb. Sel. 1: 28. 1790: Syst. Mycol. 3: 458, 466 1832, nom. cons. [non Volutella Forsk. 1775 (Lauraceae)]

Type species: Volutella ciliata (Alb. & Schw.: Fr.) Fr. 1832, typus cons.

Perithecia nonstromatic, pyriform, collapsing by lateral pinching or not collapsing when dry, brownish orange to brownish red, yellow in 100 % lactic acid, darkest around papilla, hyphal hairs covering surface, hyaline, thick walled. Perithecial wall 15–25 um wide, with two intergrading layers of angular cells; cells next to centrum thin walled; cells of layer region thick walled. Asci narrowly clavate to broadly cylindrical, apex with or without refractive ring, eight-spored. Ascospores fusiform or biconic, equally or unequally 2-celled, smooth or finely roughed, hyaline, white in mass, obliquely uniseriate or partially biseriate near base, completely filling each ascus. Conidiophores aggregated into sporodochia or synnemata, with an inconspicuous basal stroma; unbranched, hyaline setae around margin of conidiomata. Synnemata, when produced, determinate, pale, composed of a stipe of parallel hyphae and a divergent capitulum of conidiophores giving rise to a slimy conidial mass; differentiated marginal hyphae absent. Conidiophore branching once or twice monochasial, 2-level verticillate, monoverticillate or irregularly biverticillate. Conidiogenous cells monophialidic, hyaline, subulate, usually with conspicuous periclinal thickening. Conidial masses slimy, white, yellow, orange or pink. Conidia aseptate, hyaline, ellipsoidal, ovate or oblong. Chlamydospores produced in culture by some species. Verticillium-like synanamorph present in some species: Conidiophores hyaline, with 2 or more whorls of conidiogenous cells; phialides and conidia with similar characters to those described for the conidiomata. Agar cultures growing relatively slowly, usually less than 30 mm diam in 14 d, with little aerial mycelium.

Notes: Volutella is a classical hyphomycete genus that has received little study, despite the common occurrence and broad distribution of its species. The genus is typified by V. ciliata, which has sporodochial conidiomata with conspicuous hyaline, thick-walled, unbranched, spine-like setae, phialidic conidiogenous cells arising from more or less penicillately branched conidiophores, and ameroconidia accumulating in a profuse, colourful slime. Domsch et al. (2007) provided a general overview of the type and a few other soil-borne species of the genus. In anticipation of a more comprehensive revision of Volutella, the inclusion of one synnematous species in this genus is discussed here.

Volutella s. str. should be restricted to the clade that includes the type species, V. ciliata, V. consors (referred to as V. minima by Domsch et al. 2007), and the synnematous V. citrinella. The teleomorphs associated with Volutella provide clues to its polyphyly. “Cosmospora” consors was reported as the teleomorph of V. ciliata by Samuels (1977, as Nectria consors); the identity of the anamorph was later changed to V. minima by Domsch et al. (2007). This species differs from V. ciliata primarily by its cylindrical conidia. Volutella citrinella, considered at more length below, has a similar teleomorph, “Nectria” stilbellae. Neither teleomorph genus is appropriate, with Cosmospora now restricted to species with Acremonium-like anamorphs, discussed above, and Nectria is restricted to species with Tubercularia anamorphs (Hirooka et al. 2011). We have elected not to describe a new teleomorph genus for this clade, preferring to refer to these fungi by the oldest available generic name Volutella. As noted by Summerbell et al. (2011) in their discussion of Trichothecium, replacing a classic and well known generic name with a virtually unknown teleomorphically typified generic name would be taxonomically capricious. The other two holomorphic species with anamorphs attributed to Volutella are species presently classified in Pseudonectria (see above), which produce setose perithecia and aseptate ascospores, rather different than the smooth- or rough-walled perithecia and 1-septate ascospores of V. citrinella and V. consors.

The synnematous fungus V. citrinella was formerly known as Stilbella aciculosa (Seifert 1985a) but is more appropriately classified in Volutella. There have been scattered comments in the literature about synnematous species of Volutella, including the comment by Domsch et al. (2007) that some strains or species are “short stipitate”. Thus, the inclusion of synnematous species only subtly alters the existing generic concept. Although there was scant mention of Volutella in the monograph of the synnematous genus Stilbella by Seifert (1985a), it was included in the key to Stilbella-like genera because of these observations by other authors.

Few of the approximately 120 described species of Volutella have been revised, and most species were seldom reported after their original descriptions. A preliminary survey of type specimens accessioned in K by Seifert (unpublished) suggests that many of the described species represent Colletotrichum, Sarcopodium, and other anamorphic genera. Comparatively few species that conform to the modern concept were uncovered. However, given the morphological variation we have seen in unidentifed specimens and cultures, we suggest Volutella s. str. will ultimately include many more species.

This study would have been impossible without the tremendous contributions of Gary J. Samuels. His habit of sharing collections selflessly and his holistic approach to describing fungi make him a role model for both beginning and experienced mycologists. He could have been easily a co-author of this study, but then we could not have written this acknowledgement for him!

We thank Kerry O'Donnell for providing unpublished DNA sequences (rpb2) for many Fusicolla and Microcera strains deposited with NRRL. We enjoyed numerous fruitful discussions with Scott Redhead on interpretations of Article 59 of the ICBN but assume full responsibility for the nomenclatural decisions made here. We thank the curators of the herbaria B, DAOM, G, FH, K, L, PAD, PH, PRM, S, and UPS for the loan of type and other material or for searching for relevant material. We are especially indebted to Harrie Sipman at the Botanical Museum in Berlin for providing information on fungal specimens deposited by H. Richter and H.W. Wollenweber.

We appreciate the continued support of and consultation with our mentor Prof. W. Gams, who prepared the Latin diagnosis for M. samuelsii, while proclaiming his horror at the nomenclatural mutations proposed here by his devoted former students.

We are grateful for DNA sequencing by Gerry Louis-Seize, and for the support from the Canadian Collection of Fungal Cultures. Last but not least, we thank W. Jaklitsch and H. Voglmayr for permission to study their specimens of Stylonectria and the examination of type material of S. wegeliniana.