Abstract

INTRODUCTION

The genus Neocosmospora (Hypocreales, Nectriaceae) includes ubiquitous, widely distributed fungi that are commonly found in soil, plant debris, living plant material, air and water. Previously assigned to the Fusarium solani species complex (FSSC; O’Donnell 2000) and before that, to sect. Martiella (Wollenweber 1913), this genus encompasses one of the most important groups of plant pathogenic fungi. The included species and varieties have been recorded from nearly 500 different plant hosts, spanning more than 100 families (Farr & Rossman cont. updated). Common plant diseases attributed to these taxa include: dry and jelly-end potato rot (Carpenter 1915); head blight of wheat (Triticum aestivum) (Balmas et al. 2015); root rot of Citrus spp. (Menge 1988, Polizzi et al. 1992, Sandoval-Denis et al. 2018), common bean (Phaseolus vulgaris; Roy 1997), pea (Pisum sativum; Porter et al. 2015), peanut (Arachis hypogaea; Rojo et al. 2007), sweet potato (Ipomoea batatas; McClure 1951) and wheat (Nirenberg 1981); root and fruit rot of cucurbits (Hawthorne et al. 1992), and tomato (Solanum lycopersicum); stem and fruit rot of sweet peppers (Capsicum annuum; Fletcher 1994, Jarvis et al. 1994), and mango (Mangifera indica); fruit malformation (Liew et al. 2016); stem canker of cottonwood (Populus spp.; Toole 1963), avocado (Persea americana; Guarnaccia et al. 2018), red oak (Quercus rubra; Vujanovic et al. 1999), and walnut (Juglans spp.; Tisserat 1987, Chen & Swart 2000); and sudden death syndrome (SDS) of soybean (Glycine max; Achenbach et al. 1996, Aoki et al. 2005). Neocosmospora also includes economically important tree-pathogenic mutualists of the shot-hole borer beetle (Euwallaceae spp.) originally associated with dieback of avocado and tea (Camelia sinensis; Freeman et al. 2013). This mutualistic association, however, is now known from various other woody hosts that include castor bean (Ricinus communis), fig (Ficus carica), kaki persimmon (Diospyros kaki), ashleaf maple/ Manitoba maple/ box elder (Acer negundo), oak (Quercus spp.), oriental plane (Platanus orientalis), and the tree of heaven (Ailanthus altissima; Freeman et al. 2013, O’Donnell et al. 2016), as well as several native host species in South Africa (Paap et al. 2018).

Given their importance as plant pathogens, species of Neocosmospora have been used as model organisms in molecular plant pathology (VanEtten et al. 1989, Crowhurst et al. 1992, O’Donnell 2000 and additional references therein) and for the study of fungal cell biology (Wu et al. 1998, Aist 2002, Coleman 2016). They are also known as producers of bioactive natural products including antibacterial agents (Bacon et al. 1996, Merlin et al 2013); cytotoxic compounds like the immunosuppressive agents cyclosporine A and C, and naphthoquinones (Nakajima et al. 1989, Sugiura et al. 1999, Lee et al. 2014, Takemoto et al. 2014, Rathna et al. 2016, Chowdhury et al. 2017). They are sources of diverse enzymes with industrial applications including chitosanases (Liu & Bao 2009), cutinases (Mannesse 1997, Longhi et al. 2005), hydrolases (Jallouli et al. 2015), laccases (Wu & Nian 2014), and lyases (Longhi et al. 2005); and for the biosynthesis of nanoparticles (Fathima & Balakrishnan 2014).

Neocosmospora species have also sporadically been associated with human and animal mycotoxicoses (Ishii et al. 1971, Pitt & Hocking 2009, Antonissen et al. 2014), being producers of a wide range of toxins displaying activities against plants and animals, cell cultures and diverse microorganisms. The list of known toxic metabolites includes furanoterpenoids, ipomeanols and ipomeanine (Nelson et al. 1983, 1994, Mawhinney et al. 2008, Pitt & Hocking 2009), naphthazarins (Achor et al. 1993, Van Rensburg et al. 2001), while the alleged production of the trichothecenes scirpentriol, NT-2, T-1, T-2 toxins and neosolaniol are most likely based on misidentified isolates (Ishii et al. 1971, Ueno et al. 1975, Chełkowski 1989).

Despite their relative rarity compared to infections caused by other fungal pathogens such as Aspergillus and Candida spp., human and animal infections caused by Neocosmospora spp. are on the rise (Anaissie et al. 1986, Sutton & Brandt 2011). This increase is driven by a multitude of causes, mostly related to the increased incidence of specific host predisposing factors and immunocompromising conditions that include corticosteroid therapy, grafts, haematological malignancies, HIV infection, prolonged neutropenia, prosthetic devices and transplantations. Additionally, the development of new diagnostic tools and the currently improved awareness of medical personnel on the importance of fungal infections have greatly increased accurate identification of the causal agent (Guarro 2013, Slavin et al. 2015). Although nearly 50 % of fusarial infections have been attributed to the traditional concept of N. solani, recent phylogenetic studies have shown that infections due to Neocosmospora spp. are not limited to N. solani s.str. (O’Donnell et al. 2008, Guarro 2013, Sandoval-Denis & Crous 2018). Other Neocosmospora spp. that include N. petroliphila, N. falciformis, and in particular N. keratoplastica are now also known to be more frequently associated with cutaneous, subcutaneous or deep seated, commonly devastating infections of highly immunocompromised patients (Guarro 2013, Short et al. 2013).

MATERIAL AND METHODS

RESULTS

Phylogeny

The combined four gene dataset included sequences from 378 isolates, including the two outgroup taxa, Geejayesia atrofusca (NRRL 22316) and G. cicatricum (CBS 125552). The multilocus dataset included 3 281 characters (tef1 692, ITS 489, LSU 485 & rpb2 1 615), including alignment gaps. Of these, 2 061 were conserved (tef1 341, ITS 269, LSU 414 & rpb2 1 037), 1 192 were variable (tef1 337, ITS 209, LSU 68 & rpb2 578), 938 were phylogenetically informative (tef1 284, ITS 148, LSU 37 & rpb2 469), and included 1 515 Bayesian unique site patterns (tef1 433, ITS 278, LSU 97 & rpb2 707). The best-fit models of evolution selected according to the Akaike criterion were GTR+I+G for the tef1, ITS and LSU and SYM+I+G for rpb2. For BI, the 50 % majority rule tree and posterior probabilities were calculated from a total of 135 002 trees, with 22 500 trees discarded as the ‘burn-in’ phase. The topologies observed for both the ML and BI analyses where congruent.

The multilocus analyses revealed a total of 77 species-level clades within the ingroup taxa, distributed among four main clades (Fig. 1), three of which largely corresponded to Clades 1–3 resolved by O’Donnell (2000). The most basal and fully-supported (ML-BS 100 %, BI-PP 1) Clade 1 includes N. illudens and N. plagianthi, both species known from New Zealand. Clade 2 is paraphyletic, and is divided into a fully-supported monotypic lineage, here assigned to N. rectiphora and a species-rich, well-supported (ML-BS 90 %, BI-PP 0.96) main clade including mostly tropical and neo-tropical species. The more speciose, fully-supported Clade 3 resolved into 65 species clades, not showing discernible biogeographic patterns. The fully-supported Ambrosia clade (Kasson et al. 2013) is contained within Clade 1, and includes 13 species, mostly obligated symbionts of the Euwallacea fornicatus species complex (Coleoptera, Xyleborini).

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Fig. 1.

Maximum-Likelihood tree (ML) obtained from ITS, LSU, tef1 and rpb2 sequences of 376 strains from Neocosmospora species. Branch lengths are proportional to distance. Numbers on the nodes are ML bootstrap values (BS) ≥ 70 %, followed by Bayesian posterior probability values (BI-PP) ≥ 0.95. Full supported branches (ML-BS = 100 / BI-PP = 1) are indicated in bold. Line drawings representing the mean size (up) and maximum size (down) of macroconidia were plotted for each respective species clade with known morphology. Ex-type, ex-epitype, ex-isotype, ex-neotype and ex-paratype strains are indicated with ^T, ^ET, ^IT, ^NT and ^PT, respectively. The tree was rooted to Geejayesia atrofusca (NRRL 22316) and G. cicatricum (CBS 125552).

The PHI test was executed to predict genetic recombination between new species proposed here and phylogenetically related species, as well as among species with complex internal phylogenetic structures (Fig. 2). Statistically significant evidence for the existence of recombination events (Φw < 0.05) was found between the phylogenetic species FSSC 25 and FSSC 35, F. stercicola and F. witzenhousenense, as well as within the phylogenetic clades encompassing N. metavorans, N. phaseoli and N. vasinfecta. In contrast, no evidence of recombination was found between the closely related lineages corresponding to N. bataticola, N. brevicona and N. elegans. Additional data are given in the respective species notes below.

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Fig. 2.

Split graphs showing the results of the pairwise homoplasy index (PHI) tests of closely related taxa using LogDet transformation and splits decomposition. PHI test results (Φw) ≤ 0.05 indicate significant recombination within the dataset. Ex-type, ex-epitype and ex-neotype strains are in bold and indicated with ^T, ^ET and ^NT, respectively.

TAXONOMY

Neocosmospora E.F. Sm., Bull. U.S.D.A. 17: 45. 1899

Synonyms. Euricoa Bat. & H. Maia, Anais Soc. Biol. Pernambuco 13: 151. 1955.

Hyaloflorea Bat. & H. Maia, Anais Soc. Biol. Pernambuco 13: 154. 1955.

Haematonectria Samuels & Nirenberg, Stud. Mycol. 42: 134. 1999.

Type species. Neocosmospora vasinfecta E.F. Sm.

Descriptions & Illustrations — Cannon & Hawksworth (1984), Samuels & Brayford (1994), Rossman et al. (1999), Samuels et al. (2006), Nalim et al. (2011), Guarro et al. (2012), Lombard et al. (2015).

Ascomata perithecial, orange-brown to bright red, darkening in 3 % KOH, globose to pyriform, papillate or with short ostiolar neck; superficial, solitary or gregarious, non-stromatic or with a reduced basal stroma, commonly warted, rarely smooth-walled; peridium of textura angularis; asci saccate, clavate to cylindrical, unitunicate, apex simple, rounded or flattened, 8-spored; ascospores uniseriate to irregularly biseriate, globose to ellipsoid, with or without slightly truncate ends, 0–1-septate, hyaline when young becoming yellow golden-brown at maturity, thick-walled, longitudinally striate, cerebriform or spinulose. Conidiophores simple, sparingly to highly branched, mononematous (aerial conidiophores) or grouped on sporodochia. Conidiogenous cells monophialidic; aerial phialides elongate subulate to subcylindrical; sporodochial phialides doliiform, short subcylindrical to subulate. Aerial conidia subglobose, ellipsoid to clavate, 0–2(–4)-septate or falcate and multiseptate, grouped on false heads at tips of phialides. Sporodochial conidia falcate and multiseptate, thick-walled, with well-developed foot-cells.

Notes — The generic name Lachnidium (Giard 1891), has been listed as a competing synonym (Summerbell & Schroers 2002, Lombard et al. 2015) of Neocosmospora. The taxonomic history of the generic type, L. acridiorum, based on Botrytis acridiorum, a locust ectoparasite isolated in Algeria (Trabut 1891), is complex and confusing (Madelin 1966, Kendrick 1974, Lombard et al. 2015). Following Brogniart’s transfer of this locust-associated fungus to Fusarium (as F. acridiorum, Brogniart 1891), Wollenweber & Reinking (1935a) synonymized this taxon under F. solani, a broadly accepted synonymy although in conflict with the basionym’s morphological features (Madelin 1966, Summerbell & Schroers 2002, Seifert et al. 2011). Madelin (1966) concluded that the circumscription of L. acridiorum was most likely based on more than one fungus, and after studying fresh isolations of the locust parasite, transferred B. acridiorum to Trichothecium, which is accepted here. The name Neocosmospora is therefore retained for this genus as stated in Nalim et al. (2011) and Lombard et al. (2015).

The type species of the asexual genera Euricoa, E. dominguesii (ex-type culture CBS 522.63) and Hyaloflorea, H. ramosa (ex-type culture CBS 509.63) belong to Neocosmospora (Summerbell & Schroers 2002, Gräfenhan et al. 2011, Seifert et al. 2011, Lombard et al. 2015); both taxa had been previously considered synonyms of Neonectria (= Cylindrocarpon, Carmichael et al. 1980, Kirk et al. 2008), but, current phylogenetic evidence placed them as synonyms of Neocosmospora lichenicola (Sandoval-Denis & Crous 2018).

The most important morphological features that differentiate Neocosmospora from its closest relatives in Fusarium are the orange-brown to bright red perithecia producing 0–1-septate, yellow-brown, ornamented ascospores. The asexual morphs of Neocosmospora can also easily be recognised by producing long and narrow, subcylindrical aerial monophialides (acremonium-like), and their large, multiseptate, thick-walled falcate conidia with well-developed foot cells; these morphological features have been largely recognised as unique for sect. Martiella (Wollenweber 1913, 1918).

Neocosmospora acutispora Sand.-Den. & Crous, sp. nov. — MycoBank MB831170; Fig. 3

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Fig. 3.

Neocosmospora acutispora (ex-type culture CBS 145461). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–f. sporodochia formed on the surface of carnation leaves; g. chlamydospores; h–l. aerial conidiophores and phialides; m. aerial conidia; n–p. sporodochial conidiophores and phialides; q–r. sporodochial conidia. — Scale bars: c–f = 100 μm; h = 50 μm; i = 20 μm; l = 5 μm; all others = 10 μm.

Etymology. From Latin acuō, meaning ‘sharpen, make sharp’; referring to the somewhat pointed apical cells of the sporodochial macroconidia.

Typus. Guatemala, from Coffea arabica, unknown date and collector (holotype CBS H-23969 designated here, culture ex-type CBS 145461 = NRRL 22574 = BBA 62213).

Conidiophores erect from substrate mycelium and produced laterally on aerial mycelium in abundance, straight, smooth- and thin-walled, simple, sometimes reduced to a single phialide borne laterally on aerial hyphae, more rarely sparingly branched, bearing terminal, single monophialides; phialides long-ampulliform, subulate to subcylindrical, (29.5–)32.5–43(–48.5) × (3–)3.5–4.5(–5) μm (av. 38 × 4 μm, n = 40), smooth- and thin-walled, periclinal thickening inconspicuous or absent, short-, non-flared collarette often present; aerial conidia falcate to wedge-shaped and multiseptate, markedly curved apically and tapering distinctly toward both ends, basal cell moderately to distinctly notched, (3–)4–5-septate, smooth- and thick-walled; 3-septate conidia: (46–)47–52(–53) × (4.5–)5–6.5 μm (av. 49.4 × 5.6 μm, n = 10); 4-septate conidia: (48.5–)49.5–55.5(–57) × 5–6.5 μm (av. 52.5 × 5.7 μm, n = 32); 5-septate conidia: (51.5–)56–66.5(–72) × (5–)5.5–6.5(–7) μm (av. 61.2 × 6 μm, n = 58); overall: (46–)49.5–63.5(–72) × (4.5–)5.5–6.5(–7) μm (av. 57.2 × 5.9 μm, n = 100). Sporodochia straw, pale luteous to pale sienna. Sporodochial conidiophores densely packed and sparingly or densely branched, verticillately, or sympodially; sporodochial phialides subcylindrical, subulate to somewhat lageniform, (11–)14–19.5(–23) × (3.5–)4–5(–5.5) μm (av. 16.8 × 4.6 μm, n = 46), smooth- and thin-walled, periclinal thickening and collarettes inconspicuous or absent. Sporodochial conidia, falcate to somewhat straight, narrowing gently toward both ends; apical cell often longer than adjacent cell, conical with a moderately curved, rounded to somewhat pointy and slightly elongated apex; basal cell barely to distinctly notched, (4–)5–6(–7)-septate, hyaline, smooth- and thick-walled; 4-septate conidia: 53.5–57 × 5.5–6.5 μm (n = 2); 5-septate conidia: (51–)67–80(–87.5) × (5.5–)6–7 μm (av. 73.5 × 6.4 μm, n = 102); 6-septate conidia: (67–)72.5–84.5(–87.5) × 6–7 μm (av. 78.4 × 6.5 μm, n = 40); 7-septate conidia 88.5 × 6.8 μm (n = 1); overall: (51–)67–82(–88.5) × (5.5–)6–7 μm (av. 74.5 × 6.4 μm, n = 145). Chlamydospores abundant, globose to subglobose, smooth- or rough- and thick-walled, (5.5–)6–6.5(–7) μm diam, terminal or intercalary, solitary, in chains or clusters. Colonies on PDA and OA growing in the dark with an average radial growth rate of 3–4 mm/d at 24 °C, reaching 45–50 mm diam in 7 d at 24 °C; surface sulphur yellow to pale luteous, flat, velvety to felty becoming densely granular at centre, with abundant, thin concentric rings of dense aerial mycelium, then quickly becoming pionnotal; margin entire. Reverse straw, pale luteous to saffron. On OA straw, sulphur yellow to amber, flat, membranous with irregular radial patches giving a feathery appearance, velvety to somewhat granulose at periphery, quickly becoming pionnotal; margin entire. Reverse straw to pale luteous.

Notes — Neocosmopora acutispora is one of the few species strictly producing macroconidia in sporodochial and aerial conidiophores, a feature common in Clade 2 of Neocosmospora, where it nests closely related to N. keleraja, N. mahasenii and N. robusta. These last three species also lack microconidia. Neocosmospora acutispora differs from N. robusta by its predominantly 5-septate sporodochial conidia with typical elongated and somewhat constricted apical and basal cells, contrasting with the mostly 6-septate sporodochial conidia with short and rounded apical cells of the latter species. Neocosmospora keleraja and N. mahasenii are known from Asia inhabiting living and dead tree bark, and rotting wood (Nalim et al. 2011). The ex-type of N. acutispora (CBS 145461) was isolated from Coffea arabica in Guatemala, while cultural and micromorphological characteristics, including colony and sporodochia colour and especially the size of the macroconidia and its apical cells, resemble those of N. cucurbitae and N. silvicola, two members of Clade 1 of Neocosmospora. However, macroconidia in N. acutispora are more robust and less septate than in N. cucurbitae, while the macroconidia in the latter species tend to be slightly more cylindrical, especially those produced in the aerial conidiophores, which also differ significantly in shape and size from their sporodochial counterparts. The macroconidia of N. silvicola are similar in overall size, shape and degree of septation. However, macroconidia of N. acutispora have distinctly longer, not commonly hooked apical cells and less developed basal cells. In addition, aerial microconidia are abundantly formed in both N. cucurbitae and N. silvicola. Neocosmospora acutispora also differs from closely related species by its rather short, somewhat ampulliform aerial phialides.

Neocosmospora ambrosia (Gadd & Loos) L. Lombard & Crous, Stud. Mycol. 80: 227. 2015

Basionym. Monacrosporium ambrosium Gadd & Loos, Trans. Brit. Mycol. Soc. 31: 17. 1947.

Synonyms. Fusarium ambrosium (Gadd & Loos) Agnihothr. & Nirenberg, Stud. Mycol. 32: 98. 1990.

Dactylella ambrosia (Gadd & Loos) K.Q. Zhang, Xing Z. Liu & L. Cao, Mycosystema 7: 112. 1995.

Fusarium bugnicourtii Brayford, Trans. Brit. Mycol. Soc. 89: 350. 1987.

Typus. India, Upari Tea Institute, gallery of Euwallacea fornicatus infesting Camellia sinensis, 9 May 1990, V. Agnihothrudu (epitype of Monacrosporium ambrosium BPI 910524, designated by Aoki et al. (2018)). – Sri Lanka, an illustration of the fungus from a gallery of E. fornicatus on C. sinensis, C.H. Gadd & C.A. Loos (Trans. Brit. Mycol. Soc. 31: 16, f. 5 (1987) (lectotype of M. ambrosium designated by Aoki et al. (2018)).

Descriptions & Illustrations — Gadd & Loos (1947), Brayford (1987), Aoki et al. (2018).

Additional material examined. India, Upara Tea Institute, gallery of E. fornicatus in C. sinensis, 9 May 1990, V. Agnihothrudu, CBS 571.94 = BBA 65390 = MAFF 246287 = NRRL 22346 (culture ex-epitype of M. ambrosium).

Notes — Initially erroneously assigned to Monacrosporium given its oddly shaped conidia (Gadd & Loos 1947), N. ambrosia was recently described as the first representative of a single lineage, the Ambrosia clade, now belonging to Neocosmospora (O’Donnell et al. 2008). This clade includes species that share a symbiotic lifestyle and that have co-evolved with their respective hosts, members of the shot hole borer beetle genus Euwallacea (Ambrosia beetles: Coleoptera, Xyleborini; Mendel et al. 2012, Freeman et al. 2013, Kasson et al. 2013, Aoki et al. 2018). At least 12 species and one interspecific hybrid have been recognised in the Ambrosia clade of Neocosmospora. However, only four phylogenetic species have been formally described and assigned Latin binomials (Aoki et al. 2018).

The most significant morphological distinctive feature of N. ambrosia is the presence of irregularly clavate and swollen conidia, regarded as an evolutionary adaptation for its symbiotic lifestyle (Freeman et al. 2013, Kasson et al. 2013). This feature is shared, although not universally, among other members of the Ambrosia clade of Neocosmospora, particularly in N. euwallaceae and N. oligoseptata, its closest morphological allies. Neocosmospora ambrosia can be distinguished by its olive to olive-brown conidial pigmentation unlike the blue-green colouration in N. euwallaceae and always hyaline in N. oligoseptata (Freeman et al. 2013, Kasson et al. 2013, Aoki et al. 2018).

Neocosmospora ampla Sand.-Den. & Crous, sp. nov. — MycoBank MB831171; Fig. 4

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Fig. 4.

Neocosmospora ampla (ex-type culture CBS 202.32). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–e. sporodochia formed on the surface of carnation leaves; f–h. chlamydospores; i–l. aerial conidiophores; m–o. aerial macroconidia; p. microconidia; q–s. sporodochial conidiophores and phialides; t–u. sporodochial conidia. — Scale bars: c = 200 μm; d = 100 μm; e, i = 50 μm; g–h = 5 μm; all others = 10 μm.

Etymology. From Latin amplus, meaning ‘large, wide, ample’, referring to its wide sporodochial conidia.

Typus. German East Africa, from Coffea sp., c. 1930, H.W. Wollenweber (holotype CBS H-23970 designated here, culture ex-type CBS 202.32 = BBA 4170).

Conidiophores erect from vegetative mycelium, highly abundant on aerial mycelium, straight, smooth- and thin-walled, often simple or sparingly irregularly or sympodially branched, bearing terminal and lateral monophialides; phialides subulate to subcylindrical, (24–)40.5–60(–75) × (1.5–)2–3.5(–4) μm (av. 50.4 × 2.8 μm, n = 107), smooth- and thin-walled, conidiogenous loci with inconspicuous periclinal thickening and a short, non-flared, or less commonly flared collarette; aerial conidia of two types: microconidia oval, ellipsoidal, clavate to subcylindrical, straight or gently curved, 0–1(–2)-septate, hyaline, smooth- and thin-walled, (4–)7–14.5(–23.5) × (2–)2.5–4.5(–6) μm (av. 10.8 × 3.5 μm, n = 196), clustering in rather voluminous false heads on tips of monophialides; macroconidia fusiform to falcate, straight or gently dorsiventrally curved, with an indistinct papillate to notched basal cell, (1–)3(–5)-septate, smooth- and thick-walled; 1-septate conidia: (16.5–)17–30.5(–31) × 4–5.5 μm (av. 23.6 × 4.6 μm, n = 8); 3-septate conidia: (20.5–)25–37(–42.5) × (4–)4.5–6(–7.5) μm (av. 31 × 5.3 μm, n = 88); 4-septate conidia: 39 × 7 μm (n = 2); 5-septate conidia: 44.5 × 6 μm (n = 2); overall: (17–)24.5–37.5(–44.5) × (4–)4.5–6(–7.5) μm (av. 30.9 × 5.3 μm, n = 100). Sporodochia cream, light green to olivaceous, quickly developing into pionnotes. Sporodochial conidiophores densely verticillately or sympodially branched; sporodochial phialides subcylindrical, subulate to doliiform, (11.5–)13.5–22(–32.5) × (2.5–)3.5–5(–6.5) μm (av. 17.8 × 4.2 μm, n = 106), smooth- and thin-walled, conidiogenous loci with conspicuous periclinal thickening and a short, non-flared to rarely flared collarette. Sporodochial conidia almost straight to moderately dorsiventrally curved and wedge-shaped with nearly parallel lines, tapering toward base; apical cell mostly of equal length or shorter than adjacent cell, blunt with curved apex; basal cell barely notched, (1–)3–7-septate, hyaline, smooth- and thick-walled; 1-septate conidia: 26.5 × 4.5 μm (n = 2); 3-septate conidia: (29.5–)34–47(–51.5) × (4–)4.5–6(–6.5) μm (av. 40.5 × 5.2 μm, n = 42); 4-septate conidia: (38.5–)40.5–50(–55) × 5–6.5 μm (av. 45.1 × 5.8 μm, n = 44); 5-septate conidia: (42.5–)51.5–64.5(–71) × (5–)5.5–7(–7.5) μm (av. 58 × 6.4 μm, n = 100); 6-septate conidia: (59.5–)60.5–73(–85) × (6–)6.5–7.5 μm (av. 66.6 × 6.9 μm, n = 26); 7-septate conidia: (65–)66.5–75(–76.5) × 6.5–7.5 μm (av. 70.8 × 7 μm, n = 22); overall: (26.5–)43–67.5(–85) × (4–)5.5–7(–7.5) μm (av. 55.3 × 6.3 μm, n = 236). Chlamydospores abundant, globose to subglobose, smooth- and thick-walled, (3.5–)5.5–9(–10.5) μm diam, terminal or intercalary in hyphae and conidia, solitary or in chains.

Colonies on PDA growing in dark with an average radial growth rate of 3.7–4.7 mm/d at 24 °C, reaching 52–66 mm diam in 7 d at 24 °C; white, straw to pale luteous, flat with slight central elevation, velvety, felty or floccose, white to straw aerial mycelium abundant; margin entire; reverse white to pale straw. On OA incubated in dark reaching 72–86 mm diam in 7 d at 24 °C; white, cream to buff, flat, velvety to felty, commonly wit concentric rings of white to straw aerial mycelium; margin entire. Reverse white, straw to luteous.

Notes — Neocosmospora ampla is introduced here for a monotypic lineage that includes a strain originally identified by H.W. Wollenweber as F. javanicum, and later assigned to F. eumartii. However, this strain did not satisfy the morphological characteristics of either of these taxa. Contrasting with the original concept of F. javanicum (Koorders 1907, Wollenweber 1931), the original description of F. eumartii (Carpenter 1915) or the long-standing modern concept of the latter species (Gerlach & Nirenberg 1982), sporodochial conidia of N. ampla are much wider, markedly tapered and more distinctly and regularly curved, especially on its dorsal side. In addition, N. ampla exhibits somewhat shorter and blunter apical cells while foot cells are barely notched and not as pronounced as described for F. eumartii.

Another distinguishing morphological feature of N. ampla is the additional formation of aerial macroconidia, clearly differentiated from the sporodochial conidia by being slightly wider toward the base (vs wedge-shaped in the sporodochial conidia). Other species showing similarly sized and septate sporodochial conidia are N. elegans and N. quercicola. Sporodochial conidia of N. elegans are similarly tapered at both ends, although narrower (up to 6.5 μm wide and average L/W ratio of 11.8 vs up to 7.5 μm and average L/W ratio of 8.7 in N. ampla). The sporodochial conidia of N. quercicola are typically almost straight, with well-developed, somewhat protuberant foot cells. Furthermore, N. elegans and N. quercicola lack aerial macroconidia.

Neocosmospora bataticola Sand.-Den. & Crous, sp. nov. — MycoBank MB831172; Fig. 5

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Fig. 5.

Neocosmospora bataticola (ex-type culture CBS 144398). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–e. sporodochia formed on the surface of carnation leaves; f–i. aerial conidiophores; j. aerial microconidia; k. aerial macroconidia; l–o. sporodochial conidiophores and phialides; p–q. sporodochial conidia. — Scale bars: c–e = 50 μm; f–i = 20 μm; all others = 10 μm.

Synonym. (Fusarium solani f. batatas T.T. McClure, Phytopathology 41: 75. 1951. Nom. inval., Art. 39.1).

Etymology. Name refers to the plant species Ipomoea batatas from which this fungus was isolated.

Typus. USA, North Carolina, from Ipomoea batatas, unknown date and collector (holotype CBS H-23971 designated here, culture ex-type CBS 144398 = NRRL 22402 = BBA 64954 = FRC S-0567).

Conidiophores abundant on substrate and aerial mycelium, straight, smooth- and thin-walled, simple or branched several times, mostly verticillately, more rarely irregularly or sympodially, bearing terminal and lateral, single monophialides; phialides subcylindrical, subulate to acicular, (27–)32.5–45.5(–57.5) × (1.5–)2–3(–3.5) μm (av. 39 × 2.5 μm, n = 68), smooth- and thin-walled, commonly proliferating, conidiogenous loci with rather inconspicuous periclinal thickening and collarettes; aerial conidia of two types: microconidia obovate, ellipsoidal to reniform, 0–1-septate, hyaline, smooth- and thin-walled, (6.5–)7–14(–19.5) × 2–4.5(–6) μm (av. 10.3 × 3.2 μm, n = 164), clustering in false heads at tip of monophialides; macroconidia fusiform to falcate, multiseptate, straight or dorsiventrally curved, base somewhat flattened to barely notched, 1–3(–5)-septate, smooth- and thick-walled; 1-septate conidia: (13.5–)15–20.5(–23) × (2.5–)3.5–6 μm (av. 17.8 × 4.5 μm, n = 32); 2-septate conidia: 24 × 5 μm (n = 2); 3-septate conidia: (21–)24–35(–41) × (3.5–)4–6.5(–7.5) μm (av. 29.4 × 5.3 μm, n = 78); 4-septate conidia: 40–43 × 5–5.5 μm (av. 41.6 × 5.1 μm, n = 16); 5-septate conidia: 43.5 × 5 μm (n = 4); overall: (13.5–)21–37(–43.5) × (2.5–)4–6.5(–7.5) μm (av. 29 × 5.2 μm, n = 130). Sporodochia cream, light green, olivaceous buff to olivaceous. Sporodochial conidiophores sparingly verticillately or laterally branched, bearing single lateral monophialides or terminating in whorls of 2–3 or single monophialides; sporodochial phialides in sporodochia subcylindrical, subulate, ampulliform or doliiform, (10–)14–19.5(–26.5) × (3–)4–5.5(–6) μm (av. 16.9 × 4.7 μm, n = 82), smooth- and thin-walled, conidiogenous loci with inconspicuous or absent periclinal thickening and a minute, non-flared collarette. Sporodochial conidia moderately dorsiventrally curved to nearly straight, tapering gently toward both ends; apical cell of equal length or slightly longer than adjacent cell, blunt to conical with an abruptly curved to somewhat hooked, rounded apex; basal cell notched and mostly slightly extended, (3–)5–7(–8)-septate, hyaline, smooth- and thick-walled; 3-septate conidia: 30.5–41.5 × 6–6.5 μm (n = 3); 4-septate conidia: 46–46.5 × 5.5–6.5 μm (n = 3); 5-septate conidia: (47–)59.5–85(–91) × 5.5–6.5(–7) μm (av. 72.4 × 6.2 μm, n = 72); 6-septate conidia: (62.5–)73–91(–96) × (5.5–)6–6.5(–7) μm (av. 82 × 6.2 μm, n = 90); 7-septate conidia: (72–)84–96(–101.5) × (5.5–)6–6.5 μm (av. 90.1 × 6.2 μm, n = 36); 8-septate conidia: (88.5–)90.5–96.5(–97) × (5.5–)6–6.5 μm (av. 93.6 × 6.2 μm, n = 9); overall: (30.5–)65–94(–101.5) × (5.5–)6–6.5(–7) μm (av. 79.5 × 6.2 μm, n = 213). Chlamydospores globose to subglobose, smooth-walled to finely granulate and thick-walled, 7–11.5 μm diam, terminal or intercalary, solitary, in pairs or short chains.

Colonies on PDA growing in dark with an average radial growth rate of 2.6–3 mm/d at 24 °C, reaching 35–42 mm diam in 7 d at 24 °C; straw, pale luteous, sienna, saffron, orange to red, flat, velvety, felty or lanose, commonly with short aerial mycelium arranged in concentric rings and a faint radiated pattern; margin entire. Reverse white to pale straw, an amber to pure yellow diffusible pigment can be produced. On OA incubated in dark covering an entire 9 mm Petri dish in 7 d at 24 °C; white, cream, scarlet to rust, flat, velvety, felty to granulose; margin entire. Reverse ochreous to red.

Additional material examined. USA, North Carolina, from Ipomoea batatas, unknown date and collector, CBS 144397 = NRRL 22400 = BBA 64683.

Notes — Isolates treated here are representatives of the genetically and biologically well-characterised F. solani f. batatas (McClure 1951), F. solani f. sp. batatas (Matuo & Snyder 1973, O’Donnell 2000, O’Donnell et al. 2008), also known as Nec. haematococca MPII or phylogenetic species FSSC 23. Nevertheless, F. solani f. batatas was not validly published since a Latin description or diagnosis was not included (Art. 39.1). In its formae speciales nomenclature, and largely relying on its host association with Ipomoea batatas, this group was considered a synonym of Hyp. ipomoeae (now Neocosmospora ipomoeae; Matuo & Snyder 1973). This synonymy is not supported here, given their clearly distinct evolutionary origins. Moreover, other taxa have also been recovered from the same host, e.g., F. javanicum, N. brevicona (as F. solani var. minus) and N. solani (Wollenweber 1931).

The clade representing N. bataticola in this study clusters within a marginally supported clade containing N. brevicona and N. hengyangensis, both species with known sexual-morphs (Wollenweber 1930, Zeng & Zhuang 2017). However, their distinctive morphology and lack of evidence of sexual recombination (Φw > 0.6, Fig. 2) between the different clades support their recognition as distinct species.

The most noticeable macroscopic characteristic of N. bataticola is the production of intense orange to red coloured diffusible pigments on PDA and OA. This feature is particularly evident for the ex-type culture of this species. Additionally, N. bataticola also produces distinct large multiseptate, straight to moderately curved sporodochial conidia with well-developed foot cells. The sporodochial conidia are reminiscent of N. ipomoeae, as the latter species also produces similar aerial micro- and macroconidia, and both species are hardly differentiable by their asexual morphs. The aerial macroconidia of N. bataticola are typically fusiform and somewhat wider at the base in comparison to the fusiform to almost cylindrical and commonly flattened at the base, aerial macroconidia of N. ipomoeae.

Other comparable species with similar sized sporodochial conidia are N. borneensis and N. longissima, also showing similar conidial septation. However, conidia in N. bataticola are less curved and less robust, while aerial macroconidia are much smaller than those in N. borneensis or N. longissima. In contrast, microconidia are never produced in N. longissima.

Neocosmospora borneensis (Petr.) Sand.-Den. & Crous, comb. nov. — MycoBank MB831173; Fig. 6

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Fig. 6.

Neocosmospora borneensis (ex-epitype culture CBS 145462). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–g. sporodochia formed on the surface of carnation leaves; h–k. aerial conidiophores; l–m. aerial microconidia; n. aerial macroconidia; o–q. sporodochial conidiophores and phialides; r. sporodochial conidia. — Scale bars: c–g = 100 μm; h–k = 20 μm; all others = 10 μm.

Basionym. Nectria borneensis Petr., Sydowia 8: 20. 1954.

Typus. British North Borneo (Malaysia), Sabah, Tenompok, Mount Kinabalu, Jungle lodge, 25 Apr. 1933, Clemens (holotype K(M) 252860). – Indonesia, North Sulawesi, Bogani Nani Wartabone National Park (formerly the Dumoga Bone National Park), from bark of a recently dead unidentified tree, 26 Oct. 1985, G.J. Samuels (epitype of Nec. borneensis CBS H-23972 designated here, MBT387201, culture ex-epitype CBS 145462 = NRRL 22579 = BBA 65095 = G.J.S. 85-197).

Descriptions & Illustrations of the sexual morph — Samuels et al. (1990), Samuels & Brayford (1994).

Conidiophores abundant, erect or prostrate on substrate mycelium and laterally on the aerial mycelium, straight or flexuous, smooth- and thin-walled, often sparingly verruculose at basal and middle portions, simple or sparingly dichotomously branched, bearing terminal, single monophialides; phialides subulate to subcylindrical, (57–)60.5–71.5(–78.5) × (2.5–)3–4 μm (av. 66.1 × 3.3 μm, n = 52), smooth- and thin-walled, conidiogenous loci with visible periclinal thickening and a short, not-flared collarette; aerial conidia of two types: microconidia ellipsoidal to subcylindrical, straight or with a slight dorsal curvature, 0–1(–2)-septate, hyaline, smooth- and thin-walled, (6.5–)8.5–20(–29.5) × (2.5–)3.5–6(–7.5) μm (av. 14.3 × 4.6 μm, n = 95), clustering in false heads on tip of monophialides; macroconidia navicular to falcate and multiseptate, straight to gently dorsiventrally curved, base flattened, barely to moderately notched, (2–)3–5-septate, smooth- and thick-walled; 2-septate conidia: (22–)23–27(–28) × (5.5–)6–7.5 μm (av. 24.8 × 6.5 μm, n = 12); 3-septate conidia: (25.5–)30.5–44.5(–48) × (4.5–)5.5–7(–7.5) μm (av. 37.6 × 6.2 μm, n = 80); 4-septate conidia: (41–)43–50.5(–53) × (5.5–)6–7.5 μm (av. 46.8 × 6.5 μm, n = 24); 5-septate conidia: (47.5–)49.5–56.5(–59) × (5.5–)6–7 μm (av. 52.9 × 6.4 μm, n = 22); overall: (22–)31–50(–59) × (4.5–)5.5–7(–7.5) μm (av. 40.5 × 6.3 μm, n = 138). Sporodochia pale luteous, primrose to dull-green. Sporodochial conidiophores sparingly dichotomously branched or simple, densely packed; sporodochial phialides subcylindrical to cylindrical, (13.5–)18–25(–32) × (2.5–)3–4.5(–5) μm (av. 21.3 × 3.9 μm, n = 101), smooth- and thin-walled, conidiogenous loci with visible periclinal thickening and a minute, not-flared collarette. Sporodochial conidia falcate with nearly parallel lines, sometimes almost straight, narrowing gently toward base; apical of equal length to adjacent cell, conical with rounded, somewhat papillate apex; basal cell distinctly notched, 5–8(–9)-septate, hyaline, smooth- and thick-walled; 5-septate conidia: (59–)65.5–78(–79.5) × (5.5–)6–7 μm (av. 71.8 × 6.3 μm, n = 36); 6-septate conidia: (71–)73–80.5(–81.5) × 6–7 μm (av. 76.7 × 6.5 μm, n = 16); 7-septate conidia: (75–)80.5–90(–93) × 6.5–7.5(–8) μm (av. 85.2 × 7.1 μm, n = 84); 8-septate conidia: (82.5–)83–87.5(–88.5) × (6.5–)7–7.5 μm (av. 85 × 7.1 μm, n = 24); 9-septate conidia: (86.5–)88–99(–104) × 6.5–7.5 μm (av. 92.7 × 7.2 μm, n = 20); overall: (59–)74.5–91(–104) × (5.5–)6–7.5(–8) μm (av. 82.5 × 6.9 μm, n = 180). Chlamydospores not observed.

Colonies on PDA growing in dark with an average radial growth rate of 4.6–5 mm/d at 24 °C, reaching 64–70 mm diam in 7 d at 24 °C; pale luteous to ochreous, flat, felty to cottony, with conspicuous concentric rings of white aerial mycelium, becoming somewhat granulose with production of abundant pale luteous sporodochia; margin entire. Reverse pale luteous to ochreous, with pale umber patches. On OA incubated in dark reaching 70–74 mm diam in 7 d at 24 °C; flesh to pale salmon, flat, velvety; margin entire. Reverse pale luteous with peach to pale rose periphery.

Notes — The description of the asexual morph, the most common morphology observed in culture, is included to supplement the observations originally made by Samuels et al. (1990) and Samuels & Brayford (1994) of the same isolate studied here. Additional information was also partially taken from unpublished morphological notes and illustrations obtained from G.J. Samuels. The former studies also described and illustrated the sexual morph, which could not be induced on artificial media here.

Although originally described from a fungus collected on the bark of rotting branches of an unidentified plant in the Malaysian state of Sabah, the culture studied here has slightly smaller ascospores than the type collection (G.J. Samuels, pers. comm.). This culture also commonly exhibited a sparingly verruculose surface on its conidiophores, a feature not reported previously for this species but regularly observed on all the culture media studied here. Nevertheless, the studied strain was collected in North Sulawesi, Indonesia, a zone with similar environmental conditions as the holotype collection site (Sabah), while it has been regarded as a representative isolate of Nec. borneensis (Samuels et al. 1990, Samuels & Brayford 1994, O’Donnell 2000). Therefore, a specimen derived from CBS 145462 is here designated as epitype to fix the use of the species name.

According to Samuels & Brayford (1994), the sexual morph of N. borneensis cannot be differentiated morphologically from those of N. illudens or Nec. subsequens. The morphology of the asexual morph is quite unique for N. borneensis, producing much longer and more robust, up to 9-septate sporodochial conidia. Other species with similar sexual morphologies are Nec. balansae and Nec. pulcherrima (Samuels & Brayford 1994). Nectria balansae has a pycnidial asexual morph (Samuels & Brayford 1994), and it is phylogenetically related to Nectria s.str. (Chaverri et al. 2011). In contrast, Nec. pulcherrima has been morphologically connected to the genus Rugonectria (Chaverri et al. 2011).

Other species producing conidia of similar size and shape and known sexual morphs include N. ipomoeae and N. bataticola. Neocosmospora borneensis and N. ipomoeae both produce mostly 7–8-septate sporodochial conidia. Those of N. borneensis are slightly shorter and wider, often with a less pronounced curvature. Neocosmospora bataticola produces mostly 5–6-septate sporodochial conidia, which are longer, slender, less curved and more robust than those of N. borneensis. In addition, verruculose aerial conidiophores have not been observed for either N. bataticola or N. ipomoeae.

Neocosmospora bostrycoides (Wollenw. & Reinking) Sand.-Den., L. Lombard & Crous, comb. nov. — MycoBank MB831174; Fig. 7

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Fig. 7.

Neocosmospora bostrycoides (ex-neotype culture CBS 144.25). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–e. sporodochia formed on the surface of carnation leaves; f–h. chlamydospores; i–m. aerial conidiophores and phialides; n–p aerial conidia; q–r. sporodochial conidiophores; s. sporodochial conidia. — Scale bars: c–e = 100 μm; g–h, o = 5 μm; all others = 10 μm.

Basionym. Fusarium bostrycoides Wollenw. & Reinking, Phytopathology 15: 166. 1925.

Typus. Honduras, Tela, from soil, unknown date and collector (neotype of F. bostrycoides CBS H-23973 designated here, MBT387203, culture ex-neotype CBS 144.25).

Conidiophores abundant on aerial and substrate mycelium, erect and simple or reduced to conidiogenous cells, mostly densely branched laterally and verticillately, straight or flexuous, smooth- and thin-walled, bearing terminal or lateral, single monophialides; phialides subcylindrical to subulate, (27.5–)40–57(–66) × (2–)2.5–3.5(–4) μm (av. 48.5 × 2.8 μm, n = 106), smooth- and thin-walled, often proliferating, conidiogenous loci with periclinal thickening and a short-, non-flared collarette; aerial conidia obovoidal, broadly ellipsoidal to ellipsoidal, straight or rarely curved, base narrow and flattened, slightly protruding, 0(–1)-septate, hyaline, smooth- and thin-walled, 5–11.5(–21) × (2–)2.5–4.5(–6) μm (av. 8.4 × 3.4 μm, n = 91), clustering abundantly in false heads at tip of monophialides. Sporodochia cream, pale green, hazel to pale greyish sepia. Sporodochial conidiophores sparingly verticillately branched, bearing terminal whorls of 2–3-monophialides; sporodochial phialides flask-shaped, subcylindrical to short subulate, (13–)15–23.5(–29) × (2–)2.5–4(–4.5) μm (av. 19.3 × 3.4 μm, n = 48), smooth- and thin-walled, conidiogenous loci with inconspicuous periclinal thickening and collarette. Sporodochial conidia moderately to distinctly dorsiventrally curved narrowing gently toward base, dorsal line usually almost straight; apical cell often equal in length to adjacent cell, blunt and rounded with curved apex; basal cell often distinctly notched, 3–5-septate, hyaline, smooth- and thick-walled; 3-septate conidia: (29–)39.5–49.5(–54) × (4–)4.5–5.5(–6) μm (av. 44.4 × 4.9 μm, n = 124); 4-septate conidia: (41.5–)43–53(–63) × 5–6.5(–7) μm (av. 48 × 5.7 μm, n = 48); 5-septate conidia: (45–)45.5–56.5(–62) × (4.5–)5–6.5(–7) μm (av. 51 × 5.6 μm, n = 24); overall: (29–)40.5–51.5(–63) × (4–)4.5–6(–7) μm (av. 46.1 × 5.2 μm, n = 196). Chlamydospores abundantly formed, globose to subglobose, smooth- to verruculose and thick-walled, (5–)5.5–7.5(–8) μm diam, terminal or intercalary in hyphae or conidia, solitary, in chains or in clusters.

Colonies on PDA growing in dark with an average radial growth rate of 2–2.8 mm/d at 24 °C, reaching 36–40 mm diam in 7 d at 24 °C; straw, buff to pale luteous, flat, membranous, velvety to granulose, floccose at centre, with or without concentric rings of aerial mycelium; margin entire. Reverse straw to pale luteous. On OA incubated in dark covering a 9 mm diam Petri Dish in 7 d at 24 °C; white to pale straw, flat, velvety, cottony to granular with entire margin. Reverse pale straw to buff.

Additional materials examined. Brazil, Sao Paulo, human eye lesion, 22 Feb. 2000, P. Godoy, CBS 130391 = NRRL 46707 = FMR 8030. – Colombia, Araracuaro, leaf litter, Feb. 2000, C. López-Quintero, CBS 102824. – USA, from human oral wound of leukaemia patient, unknown date and collector, CBS 130328 = NRRL 31169. – Unknown, from fungus garden of Atta sp., unknown date and collector, CBS 239.39 = NRRL 22656; from seed of Bertholletia excelsa, Nov. 1965, W. Gams, CBS 392.66 = BBA 69595 = NRRL 25325.

Notes — Significant evidence links one of the strains examined here (CBS 144.25) to authentic material of F. bostrycoides, also matching with the collection data and morphological features depicted in Wollenweber & Reinking (1925), Reinking & Wollenweber (1927) and ‘Fusaria Autographice Delineata No. 978’ (Wollenweber 1930). This particular culture was received at the WI in 1925, sent by the head pathologist of the Bureau of Plant Industry, US Department of Agriculture, where the original cultures of all the new species and varieties described in Wollenweber & Reinking (1925) were kept. However, since the type status of CBS 144.25 could not be unambiguously established and no type was selected nor illustrations were made in the protologue of F. bostrycoides, a specimen derived from CBS 144.25 is here selected as neotype, in order to fix the use of the name. The morphological characteristics of this clade are strikingly similar to those described for F. bostrycoides, easily recognisable by its relatively short, mostly 3-septate macroconidia, which resemble those of F. oxysporum. This feature partially explains its former allocation in the morphological sect. Elegans (subsection Orthoceras), resulting in its posterior synonymy with F. oxysporum s.lat. (Wollenweber & Reinking 1925, Reinking & Wollenweber 1927, Domsch et al. 2007). One of the most important characteristics of the species, its highly branched conidiophores bearing terminal, long and slender monophialides, allocate this species in sect. Martiella. This is further confirmed here by DNA sequence data, demonstrating that the former circumscription of this taxon was incorrect. Furthermore, the morphology of additional strains examined here demonstrated that N. bostrycoides can also produce typical 3–5-septate, robust sporodochial conidia, more characteristic of sect. Martiella, hence the name is resurrected and recombined as N. bostrycoides.

Neocosmospora bostrycoides (as the phylogenetic species FSSC 25 and 35) has also been isolated from clinical samples (human and animal; O’Donnell et al. 2008, 2012, Herkert et al. 2019) and is, therefore, considered a putative agent of opportunistic infections. The current circumscription also includes strains obtained from human clinical specimens. However, the pathogenicity of this species is doubtful.

The clade representing N. bostrycoides includes two previously determined phylogenetic species FSSC 25 and FSSC 35 (O’Donnell et al. 2008). Based on morphological and phylogenetic data, and as significant evidence of sexual recombination was found between the two subclades (Φw = 0.006, Fig. 2), these are here reduced to a single species.

Neocosmospora brevicona (Wollenw.) Sand.-Den. & Crous, comb. & stat. nov. — MycoBank MB831175; Fig. 8

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Fig. 8.

Neocosmospora brevicona (ex-epitype culture CBS 204.31). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–f. sporodochia formed on the surface of carnation leaves; g–h. chlamydospores; i–l. aerial conidiophores; m. aerial microconidia; n–o. aerial macroconidia; p–r. sporodochial conidiophores and phialides; s–t. sporodochial conidia. — Scale bars: c–e = 100 μm; f = 50 μm; i, k–l = 20 μm; q–r = 5 μm, all others = 10 μm.

Basionym. Hypomyces haematococcus var. breviconus Wollenw., Fusaria Autographice Delineata 3: 828. 1930.

Synonyms. Nectria haematococca var. brevicona (Wollenw.) Gerlach, Fusarium: Diseases, Biology, and Taxonomy (Philadelphia): 422. 1981.

Fusarium solani var. minus Wollenw., Die Fusarien: 134. 1935.

Typus. Indonesia, Java, Buitenzorg, from rotten bulb of Gladiolus sp., Jan. 1926, unknown collector (lectotype of Hyp. haematococcus var. breviconus designated here: illustration f. 828 in Wollenweber HW (1930). Fusaria Autographice Delineata 3: no. 828, MBT387205); from Gladiolus sp., 1926, unknown collector (epitype of Hyp. haematococcus var. breviconus CBS H-23974 designated here, MBT387206, culture ex-epitype CBS 204.31 = BBA 2123 = NRRL 22659).

Conidiophores erect and prostrate on substrate mycelium, or most commonly borne laterally on aerial mycelium, straight, smooth- and thin-walled, simple, sparingly or branched multiple times verticillately or sympodially, bearing terminal and lateral, single monophialides; phialides subulate to subcylindrical, (26.5–)40–53.5(–59.5) × 2–3.5(–4) μm (av. 46.6 × 2.8 μm, n = 74), smooth- and thin-walled, conidiogenous loci with noticeable periclinal thickening and a short, non- to somewhat flared collarette; aerial conidia of two types: microconidia obovoidal, ellipsoidal, clavate to somewhat reniform, straight or gently curved, 0(–1)-septate, hyaline, smooth- and thin-walled, (3.5–)5–11.5(–20.5) × (2–)3–4(–5) μm (av. 8.4 × 3.4 μm, n = 159), clustering in false heads at tip of monophialides; macroconidia fusiform to falcate and multiseptate, straight to gently dorsiventrally curved, base blunt to inconspicuously notched, 1–3(–4)-septate, smooth- and thick-walled; 1-septate conidia: (16–)17.5–22 × (3–)4–5.5 μm (av. 19.6 × 4.5 μm, n = 16); 2-septate conidia: (18–)19–28.5(–30.5) × 3.5–5.5 μm (av. 23.6 × 4.3 μm, n = 14); 3-septate conidia: (21–)25–37.5(–43) × (4–)4.5–6(–6.5) μm (av. 31.3 × 5.1 μm, n = 64); 4-septate conidia: 44 × 5.5 μm (n = 2); overall: (16–)21–36.5(–44) × (3–)4–5.5(–6.5) μm (av. 28.8 × 4.9 μm, n = 96). Sporodochia cream, pale rosy buff to pale green. Sporodochial conidiophores simple or sparingly verticillately branched, bearing terminal monophialides, single or in whorls of 2–3 phialides; sporodochial phialides subcylindrical to subulate, 14.5–16.5 × (3–)4–5.5(–6.5) μm (av. 15.5 × 3.7 μm, n = 30), smooth- and thin-walled, conidiogenous loci with inconspicuous periclinal thickening, a short, not-flared collarette may be present. Sporodochial conidia, falcate and moderately curved; apical cell of equal length than adjacent cell, blunt with rounded and discreetly curved apex; basal cell notched, protruding slightly, (3–)4–7-septate, hyaline, smooth- and thick-walled; 3-septate conidia: (29–)32–41.5(–43.5) × 5–6.5 μm (av. 37.7 × 5.8 μm, n = 16); 4-septate conidia: (38–)38.5–43.5(–47) × 5.5–6.5 μm (av. 40.7 × 6 μm, n = 28); 5-septate conidia: (42.5–)51.5–64.5(–69.5) × (5.5–)6–7(–7.5) μm (av. 58 × 6.4 μm, n = 120); 6-septate conidia: (59.5–)62–68.5(–71) × (5.5–)6.5–7.5 μm (av. 65.1 × 6.7 μm, n = 48); 7-septate conidia: (64.5–)66–73(–74.5) × 6.5–7.5 μm (av. 69.5 × 6.9 μm, n = 36); overall: (29–)47–68.5(–74.5) × (5–)6–7(–7.5) μm (av. 57.8 × 6.5 μm, n = 248). Chlamydospores globose to subglobose, smooth- or slightly verrucose and thick-walled, (5.5–)6.5–8.5(–9.5) μm diam, abundantly formed terminally or intercalary on hyphae or conidia, solitary, in chains or clusters. Colonies on PDA growing in dark with an average radial growth rate of 22–25 mm/d at 24 °C, reaching 61–70 mm diam in 7 d at 24 °C; white, pale luteous to primrose, flat, velvety to cottony, with or without white to straw concentric rings; margin entire. Reverse white to pale straw. On OA incubated in dark reaching 75–82 mm diam in 7 d at 24 °C; white, buff to primrose, flat with more or less defined concentric rings of white mycelium and buff sporodochia, velvety to floccose; margin entire. Reverse white, straw to buff.

Additional material examined. Honduras, Ulna District, Tela, on Musa × sapientum, 17 Feb. 1923, O.A. Reinking, BPI 453021. – Philippines, Los Baños, from twig, 1925, H.W. Wollenweber, CBS 203.31 = NRRL 22234 = BBA 2019.

Notes — Isolate CBS 204.31 was deposited in WI and identified by H.W. Wollenweber as Fusarium solani var. minus. It matches the original collection site, date and host reported in the protologue of its sexual morph Hyp. haematococcus var. breviconus, presumably representing authentic material of the latter taxon (Wollenweber 1930). Nevertheless, no type was designated and it is not possible to unequivocally assign CBS 204.31 as the ex-type of the latter variety. The designation N. brevicona is coined here based on Hyp. haematococcus var. breviconus. To preserve its taxonomic concept, the name is fixed by lectotypification based on the original illustration which is reproduced here (Fig. 9). Furthermore, CBS 204.31 is apparently a subculture from the authentic collection of this species, and is here designated as epitype.

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Fig. 9.

Neocosmospora brevicona (lectotype of Hypomyces haematococcus var. breviconus) as illustrated in the protologue by Wollenweber (1930).

The morphological features observed in this clade are similar to Wollenweber’s concept for F. solani var. minus and Hyp. haematococcus var. breviconus, especially regarding the morphological features of the aerial macroconidia. The original description of Hyp. haematococcus var. breviconus is clearly based on a mixture of aerial and sporodochial conidia, as depicted in Wollenweber (1930, No 828). No sexual morph developed in culture; the selected epitype is probably derived from the original collection where the sexual morph was present.

Previous descriptions of this taxon presumably included morphological characters from other taxa, especially N. solani s.str., which is also supported by the extensive list of host species commonly cited (Wollenweber 1931, Wollenweber & Reinking 1935a, b). Wollenweber (1931) synonymises F. solani var. minus under F. carneolum Sacc., an obscure, not effectively published species, and homonym of the later validly published F. carneolum (Karsten 1888). The latter species is morphologically unrelated to F. solani var. minus. This synonymy was also followed by Hering (1997). However, their concept of the species was polyphyletic according to available DNA sequence data of strains identified as such at that time. Fusarium caucasicum has also been treated as a synonym (Hering 1997). The ex-type culture of this species was examined here and found to represent a Fusarium species significantly different from the protologue or most modern observations (Gerlach & Nirenberg 1982; see notes under F. caucasicum).

Other taxa have also been cited as synonymous with Hyp. haematococcus var. breviconus, namely Fusarium roseum var. cucurbitacearum and F. uredinicola Petch (Wollenweber 1931) for which some authors have given nomenclatural priority (Hering 1997, Schütt 2001). However, these names were either not effectively published or are illegitimate, hence are not considered here, and the varietal name is raised to species level.

Neocosmospora brevis Sand.-Den. & Crous, sp. nov. — MycoBank MB831176; Fig. 10

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Fig. 10.

Neocosmospora brevis (ex-type culture CBS 144387). a–c. Colonies (a–b. PDA obverse and reverse, respectively; c. OA) after 14 d at 24 °C in the dark; d–e. aerial conidiophores; f–g. chlamydospores; h–j. aerial conidia; k. sporodochial conidia. — Scale bars: d = 20 μm; all others = 10 μm.

Etymology. From Latin brevis, meaning ‘short, small’; referring to its small sized macroconidia.

Typus. Belgium, Heverlee, soil-water polluted with diethyleneglycerol and ethylenglycerol, unknown date, G.L. Hennebert (holotype CBS H-23975 designated here, culture ex-type CBS 144387 = MUCL 16108).

Conidiophores scarce and scattered, erect and prostrate on substrate mycelium or on aerial mycelium, straight, smooth- and thin-walled, branched several times verticillately or sympodially or unbranched bearing terminal monophialides; phialides subulate to subcylindrical, (30–)36.5–59(–75.5) × 2–3(–3.5) μm (av. 47.6 × 2.6 μm, n = 88), smooth- and thin-walled, conidiogenous loci with rather conspicuous periclinal thickening and a non-flared collarette; aerial conidia of two types: microconidia oval, ellipsoidal to subclavate, often with somewhat flattened basal and apical ends, straight or slightly curved, 0–1(–2)-septate, hyaline, smooth- and thin-walled, (5.5–)7–17.5(–27) × (2–)3–5.5 μm (av. 12.4 × 3.9 μm, n = 214), clustering in false heads at tip of monophialides; macroconidia falcate, multiseptate, slightly dorsiventrally, curved, curvature slightly more pronounced toward base, apical cell blunt and rounded, basal cell without a well-developed foot shape to barely notched, 3–5-septate, smooth- and thick-walled; 3-septate conidia: (20–)24.5–37(–43.5) × (4–)5–6(–6.5) μm (av. 30.8 × 5.5 μm, n = 128); 4-septate conidia: 39.5–49(–52.5) × (5–)5.5–6 μm (av. 44.2 × 5.7 μm, n = 82); 5-septate conidia: 42.5–48.5(–49.5) × (5.5–)6–6.5 μm (av. 45.5 × 6.2 μm, n = 40); overall: (20–)28.5–46.5(–52.5) × (4–)5–6.5 μm (av. 37.5 × 5.7 μm, n = 250); Sporodochia not observed. Chlamydospores abundant, globose to subglobose, smooth- and thick-walled, (5–)6.5–9.5(–11) μm diam, terminal or intercalary on hyphae or conidia, solitary or in chains.

Colonies on PDA growing in dark with an average radial growth rate of 2.4–2.8 mm/d at 24 °C, reaching 33–40 mm diam in 7 d at 24 °C; orange to saffron with straw to pale luteous periphery, flat, velvety with cottony to felty patches of white aerial mycelia and fine, short mycelia forming multiple concentric rings; margin entire. Reverse orange, luteous to amber, with scarce straw to bright orange diffusible pigment. On OA incubated in dark reaching 28–40 mm diam in 7 d at 24 °C; white, straw to buff, flat, dusty, velvety to floccose, margin entire. Reverse buff.

Additional materials examined. Italy, Catania, from Citrus sinensis, 2015, V. Guarnaccia, CPC 27190, CPC 27191. – USA, Texas, from human eye, unknown collector and date, CBS 130326 = NRRL 28009 = CDC B-5543.

Notes — Microconidia were the dominant conidial type observed for N. brevis, although not abundant. Aerial macroconidia were rarely observed, and true sporodochia were not observed. Abortive sporodochium-like structures forming irregularly shaped, rounded multiseptate conidia were only rarely present in the ex-type culture, formed on the agar surface on PDA and SNA; however, they were not considered in the species description.

Neocosmospora brevis is morphologically similar to but phylogenetically distant from N. diminuta. Both species are characterised by the absence of true sporodochia and presence of short falcate, multiseptate conidia produced from aerial conidiophores, where macro- and microconidia are produced in an apparent mixture. However, true macroconidia with well-developed foot cells are rare. Neocosmospora brevis differs from N. diminuta by having larger, more elongated microconidia (av. 12.4 × 3.9 μm vs 6.6 × 2.8 μm in N. diminuta) and longer, more regularly septate macroconidia (up to 52.5 μm long and 3–5-septate vs up to 38 μm long and 1–3-septate in N. diminuta). In addition, N. diminuta is homothallic and therefore develops the sexual morph readily, whereas a sexual morph is not known for N. brevis.

Currently, N. brevis includes isolates of clinical origin; whether this species encompasses true infectious agents or merely contaminants is not known.

Neocosmospora catenata Sand.-Den. & Crous, Persoonia 41: 115. 2018

Typus. USA, Georgia, from multiple tissues of Stegostoma fasciatum, unknown date and collector (holotype CBS H-23225, culture ex-type CBS 143229 = NRRL 54993 = UTHSC 09-1009).

Description & Illustration — Sandoval-Denis & Crous (2018).

Additional material examined. USA, Georgia, S. fasciatum multiple tissues, unknown date and collector, CBS 143228 = NRRL 54992 = UTHSC 09-1008.

Notes — This species was recently described from clinical animal specimens. Its circumscription encompasses the phylogenetic species previously known as FSSC 43 (O’Donnell et al. 2016, Sandoval-Denis & Crous 2018).

Neocosmospora crassa Sand.-Den. & Crous, sp. nov. — MycoBank MB831177; Fig. 11

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Fig. 11.

Neocosmospora crassa (ex-type culture CBS 144386). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–d. sporodochia formed on the surface of carnation leaves; e–k. aerial conidiophores and phialides; l–o. aerial conidia; p. sporodochial conidiophore and phialides; q–s. chlamy-dospores; t. sporodochial conidia. — Scale bars: c–d = 50 μm; all others = 10 μm.

Etymology. From Latin crassus meaning ‘thick, fat’; referring to its wide sporodochial conidia.

Typus. France, Paris, unknown substrate and date, J. Brun (holotype CBS H-23976 designated here, culture ex-type CBS 144386 = MUCL 11420).

Conidiophores on aerial mycelium straight, smooth- and thin-walled, mostly simple or sparingly irregularly branched, bearing terminal, single monophialides; phialides subcylindrical, subulate to somewhat acicular, (24.5–)49–69.5(–81.5) × (1.5–)2.5–4 μm (av. 59.4 × 3.2 μm, n = 154), smooth- and thin-walled, conidiogenous loci with inconspicuous periclinal thickening, collarettes short and non-flared; aerial conidia of two types: microconidia oval, ellipsoidal to subcylindrical, straight, often with a flattened base, straight to slightly curved, 0–1-septate, hyaline, smooth- and thin-walled, (8–)11.5–21.5(–25) × 4–6(–6.5) μm (av. 16.4 × 5 μm, n = 66), clustering in false heads at tip of monophialides; macroconidia fusiform to falcate, with a small flattened base or barely notched, straight to slightly curved, (1–)2–3-septate, hyaline, smooth- and thin-walled; 1-septate conidia: (13.5–)16–23.5(–25) × (4.5–)5–6(–6.5) μm (av. 19.7 × 5.4 μm, n = 36); 2-septate conidia: 24–25 × 5–6 μm (n = 4); 3-septate conidia: (25–)26.5–34.5(–39) × (5.5–)6–7 μm (av. 29.8 × 6.5 μm, n = 12); overall: (13.5–)16.5–28(–39) × (4.5–)5–6.5(–7) μm (av. 22.4 × 5.7 μm, n = 52). Sporodochia white, cream, light yellow-brown to green coloured. Sporodochial conidiophores densely irregularly to verticillately branched; sporodochial phialides subulate to doliiform, (10.5–)12–17(–18.5) × (3–)3.5–4.5(–5) μm (av. 14.4 × 4 μm, n = 92), smooth- and thin-walled, conidiogenous loci with inconspicuous periclinal thickening and a minute, non-flared collarette. Sporodochial conidia straight to slightly dorsiventrally curved with nearly parallel lines, often gently widening at centre or basal half and tapering gently toward both ends; apical cell blunt and often shorter than adjacent cell; basal cell barely to distinctly notched and prominent, 3–5-septate, hyaline, smooth- and thick-walled; 3-septate conidia: (26.5–)32–41.5 × (5–)6–7 μm (av. 36.9 × 6.4 μm, n = 24); 4-septate conidia: (41.5–)43.5–50(–51) × 5.5–7(–7.5) μm (av. 46.5 × 6.2 μm, n = 80); 5-septate conidia: (44.5–)47–52(–54.5) × (5.5–)6–7(–7.5) μm (av. 49.5 × 6.3 μm, n = 64); overall: (26.5–)41–51.5(–54.5) × (5–)6–7(–7.5) μm (av. 46.3 × 6.3 μm, n = 168). Chlamydospores abundant, globose to subglobose, smooth- and thick-walled, (5.5–)6.5–9(–10) μm diam, terminal or intercalary in hyphae, solitary or in chains.

Colonies on PDA growing in dark with an average radial growth rate of 5–5.6 mm/d at 24 °C, reaching 70–80 mm diam in 7 d at 24 °C; white, straw to buff, flat, felty to floccose; margin entire. Reverse white to pale straw. On OA incubated in dark covering an entire 90 mm diam Petri dish in 7 d at 24 °C; white, quickly becoming cream, pale luteous to buff; flat, velvety to felty, margin entire. Reverse white to straw.

Notes — Informally known as phylogenetic species FSSC 34 (O’Donnell et al. 2008), this clade is characterised by isolates originating from a vast array of hosts, including human clinical samples from superficial infections (Migheli et al. 2010).

Neocosmospora crassa is morphologically similar to N. pseudoradicicola and N. pseudotonkinensis, based on size and septation of the sporodochial conidia. However, N. crassa differs from N. pseudoradicicola by having much wider sporodochial conidia (av. width 6.3 μm vs 4.7 μm in N. pseudoradicicola), straighter and with less hooked apical cells, and an absence of microcyclic conidiation. In addition, the latter species exhibits only 0–1-septate microconidia. The morphological differentiation between N. crassa and N. pseudotonkinensis is less straightforward. Both species are clearly delimited and are distant phylogenetically, although they share remarkably similar cultural and microscopic features. Nonetheless, N. crassa shows slight differences in its conidial shape, being typically wider in the lower half, with less protuberant foot cells. In contrast, those of N. pseudotonkinensis are typically more tapered and wedge-shaped.

Neocosmospora cryptoseptata Sand.-Den. & Crous, sp. nov. — MycoBank MB831178; Fig. 12

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Fig. 12.

Neocosmospora cryptoseptata (ex-type culture CBS 145463). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–d. sporodochial formed on the surface of carnation leaves; e–j. aerial conidiophores; k. aerial conidia; l. sporodochia formed on the agar surface; m–n. sporodochial conidiophores and phialides; o–p. sporodochial conidia. — Scale bars: c–d = 100 μm; e = 50 μm; f–i, l = 20 μm all others = 10 μm.

Etymology. From Latin crypto meaning ‘secret or covert’, and sēptum meaning ‘enclosure, fence’; referring to the indistinct septation of the conidia.

Typus. French Guiana, from bark, unknown date and collector (holotype CBS H-23977 designated here, culture ex-type CBS 145463 = NRRL 22412 = BBA 65024).

Conidiophores abundant, formed laterally on aerial mycelium or erect on substrate mycelium, smooth- and thick-walled, often simple and straight, rarely sparingly laterally branched, proliferating sympodially and laterally from below conidiogenous loci, bearing terminal, single monophialides; phialides subcylindrical, subulate to somewhat lageniform, (39–)42.5–55(–62.5) × (3.5–)4–6(–6.5) μm (av. 48.9 × 5 μm, n = 72), smooth- and thin-walled, conidiogenous loci with inconspicuous periclinal thickening and non-flared, minute collarettes; aerial conidia falcate to wedge-shaped and multiseptate, base somewhat flattened, with an inconspicuous foot cell or distinctly and irregularly notched, 3–5(–6)-septate, smooth- and thick-walled; 3-septate conidia: (39–)42–50(–51) × (5.5–)6–7 μm (av. 45.9 × 6.4 μm, n = 36); 4-septate conidia: (49.5–)53–61(–62) × 6–7.5 μm (av. 57.1 × 6.6 μm, n = 28); 5-septate conidia: (42–)54–70.5(–71) × (5.5–)6–7 μm (av. 62.3 × 6.6 μm, n = 68); 6-septate conidia: 65–67.5 × 6–6.5 μm (av. 66.4 × 6.5 μm, n = 12); overall: (39–)48–67(–71) × (5.5–)6–7(–7.5) μm (av. 57.5 × 6.6 μm, n = 144). Sporodochia cream, straw, pale luteous to pale citrine coloured. Sporodochial conidiophores verticillately or laterally branched, bearing terminal, single monophialides or terminal whorls of up to three monophialides; sporodochial phialides subulate to lageniform, (10.5–)11.5–16.5(–20.5) × (3–)3.5–4.5(–5.5) μm (av. 14.1 × 4.1 μm, n = 56), smooth- and thin-walled, conidiogenous loci with inconspicuous periclinal thickening and a short or absent, non-flared collarette. Sporodochial conidia, falcate, rarely straight with curved ends, tapering toward base, septation often indistinct or with thin transverse septa; apical cell shorter than adjacent cell, blunt to somewhat conical with slight to markedly curved and rounded apex; basal cell inconspicuously to moderately notched to somewhat papillate, (3–)4–5-septate, hyaline, smooth- and thick-walled; 3-septate conidia: 53 × 7 μm (n = 4); 4-septate conidia: (52.5–)53.5–57.5(–59.5) × 5.5–6.5(–7) μm (av. 55.5 × 6.1 μm, n = 144); 5-septate conidia: (52.5–)55–61(–62.5) × (5.5–)6–6.5(–7) μm (av. 58 × 6.3 μm, n = 112); overall: (52.5–)53.5–59.5(–62.5) × (5.5–)6–6.5(–7) μm (av. 56.5 × 6.2 μm, n = 260). Chlamydospores not observed.Colonies on PDA growing in dark with an average radial growth rate of 2.5–3 mm/d at 24 °C, reaching 40–43 mm diam in 7 d at 24 °C; straw, pale luteous to pale ochreous, flat or inconspicuously radially folded, velvety to felty, with concentric rings of short aerial mycelium; margin filiform. Reverse white, pale straw to pale luteous. On OA incubated in dark reaching 38–41 mm diam in 7 d at 24 °C; pale luteous to pale sienna with white margin, flat, velvety and quickly becoming pionnotal; margin entire. Reverse pale luteous with umber to pale sienna centre.

Notes — Neocosmospora cryptoseptata is one of the few species in the genus lacking microconidia. Except for N. phaseoli, a lack of microconidia is a common feature for species within Clade 2 of Neocosmospora sensu O’Donnell (2000). The sporodochial conidia produced by this species, and to a lesser extent, the aerial conidia often appear to have indistinct septation, commonly with thin septal walls, often masked by fine but dense granular cell content. This feature has been reported for F. caeruleum, a species which is not related to Neocosmospora (see notes under F. caeruleum in ‘Doubtful and Excluded Taxa’).

In terms of sporodochial conidial size, N. cryptoseptata is related to N. regularis and N. bostrycoides. The latter two species differ in several aspects including conidial shape. Neocosmospora cryptoseptata produces less curved conidia, with shorter and rounder apical cells, and less pronounced foot cells. The absence of microconidia in N. cryptoseptata (present in the other two species), branching of the aerial conidiophores (profusely branched in N. bostrycoides), and the presence of microcyclic conidiation in N. regularis clearly distinguish these species from one another.

Similarly shaped sporodochial conidia are produced by N. robusta, a species also lacking microconidia and phylogenetically related to N. cryptoseptata. In the latter species the conidia are significantly shorter and less septate (av. 56.5 μm long, 3–5-septate, mostly 3-septate vs av. 69.1 μm long, up to 7-septate, mostly 6-septate in N. robusta).

Neocosmospora cucurbitae Sand.-Den., L. Lombard & Crous, sp. nov. — MycoBank MB831179; Fig. 13

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Fig. 13.

Neocosmospora cucurbitae (ex-type culture CBS 616.66). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–g. sporodochia formed on the surface of carnation leaves; h–j. chlamydospores; k–m. aerial conidiophores; n. aerial conidia; o–s. sporodochial conidiophores and phialides; t. sporodochial conidia. — Scale bars: c, e, o = 100 μm; d, f–g = 50 μm; h–j = 5 μm; k = 20 μm; all others = 10 μm.

Synonyms. Fusarium solani f. cucurbitae W.C. Snyder & H.N. Hansen, Amer. J. Bot. 28: 740. 1941.

Fusarium solani f. sp. cucurbitae W.C. Snyder & H.N. Hansen, Root rots caused by Phycomycetes 28: 740. 1941.

Hypomyces solani f. cucurbitae W.C. Snyder & H.N. Hansen, Amer. J. Bot. 28: 741. 1941.

Nectria haematococca var. cucurbitae (W.C. Snyder & H.N. Hansen) Dingley, New Zealand J. Agric. Res. 4: 337. 1961.

Nectria solani f. cucurbitae (W.C. Snyder & H.N. Hansen) G.R.W. Arnold, Z. Pilzk. 37: 193. 1972.

Etymology. Name refers to the plant genus Cucurbita from which this fungus was isolated.

Typus. Netherlands, from Cucurbita viciifolia, unknown date and collector (holotype CBS H-23978 designated here, culture ex-type CBS 616.66 = NRRL 22399 = BBA 64411).

Conidiophores mostly erect and simple, rarely sparingly branched, borne on substrate and aerial mycelium, straight, smooth- and thin-walled, bearing terminal, single monophialides; phialides subcylindrical to cylindrical, (11.5–)17.5–35(–52) × (2–)3–4.5(–6) μm (av. 26.3 × 3.6 μm, n = 55), smooth- and thin-walled, conidiogenous loci with conspicuous periclinal thickening and a short, non-flared collarette; aerial conidia of two types: microconidia ellipsoidal to clavate, straight, 0–2(–3)-septate, hyaline, smooth- and thin-walled, (4–)6.5–17.5(–42) × (2.5–)3–5 μm (av. 12 × 3.5 μm, n = 155), clustering in false heads at tip of monophialides; macroconidia falcate to cylindrical and multiseptate, moderately dorsiventrally curved, base rounded or barely notched, 2–3(–4)-septate, smooth- and thick-walled; 2-septate conidia: (19–)22–31.5(–36.5) × (3–)4–5(–6) μm (av. 26.5 × 4.3 μm, n = 48); 3-septate conidia: (17–)26–41.5(–51.5) × (3–)4–5(–6) μm (av. 33.6 × 4.4 μm, n = 44); 4-septate conidia: (36.5–)38.5–50.5(–51) × 4–5.5(–6) μm (av. 44.4 × 4.7 μm, n = 12); overall: (16.5–)22.5–40(–51.5) × (3–)3.5–5(–6) μm (av. 31.1 × 4.4 μm, n = 106). Sporodochia cream, light green to pale luteous. Sporodochial conidiophores sparingly verticillately branched, densely packed; sporodochial phialides subcylindrical, subulate to ampulliform, (11.5–)12–18.5(–27) × (3–)3.5–4.5(–5) μm (av. 15.3 × 4 μm, n = 52), smooth- and thin-walled, conidiogenous loci with inconspicuous periclinal thickening and a minute, non-flared collarette. Sporodochial conidia moderately curved to wedge-shaped, narrowing gently toward base; apical cell of about equal length to the adjacent cell, blunt with rounded, somewhat papillate curved apex; basal cell distinctly notched, (4–)5–8(–9)-septate, hyaline, smooth- and thick-walled; 4-septate conidia: 42.7–57.5(–65.5) × 4–5.5 μm (av. 50.1 × 4.8 μm, n = 18); 5-septate conidia: (47–)55–74.5(–88) × (4–)4.5–5.5(–6) μm (av. 64.8 × 5 μm, n = 44); 6-septate conidia: (67.5–)70–81(–91) × (4.5–)5–6.5 μm (av. 75.6 × 5.4 μm, n = 39); 7-septate conidia: 73.5–74.5(–86) × 4.5–6 μm (av. 79.1 × 5.3 μm, n = 30); 8-septate conidia: (78–)81–91 × 5.5–6 μm (av. 86 × 5.7 μm, n = 8); 9-septate conidia: (87.5–)90–102 × 5.5–6.5 μm (av. 96.2 × 6.1 μm, n = 5); overall: (42.5–)59–83(–102) × (4–)4.5–6(–6.5) μm (av. 71.1 × 5.2 μm, n = 144). Chlamydospores globose to subglobose, smooth- or rough- and thick-walled, (4.5–)5.5–8(–9) μm diam, terminal or intercalary in hyphae or conidia, solitary or in chains. Colonies on PDA growing in dark with an average radial growth rate of 2.4–4.2 mm/d at 24 °C, reaching 34–59 mm diam in 7 d at 24 °C; straw to pale luteous, flat, velvety to felty with concentric floccose rings of white to straw aerial mycelium; margin entire. Reverse white to pale straw. On OA incubated in dark filling an entire 90 mm diam Petri dish in 7 d at 24 °C; white to straw, flat, membranous, velvety to granular; margin entire. Reverse straw to buff.

Additional material examined. Netherlands, from Cucurbita viciifolia, unknown date, Lab. W.C. Scholten, CBS 410.62 = NRRL 22658 = CECT 2864.

Notes — This clade is informally known as phylogenetic species FSSC 10, F. solani f. sp. cucurbitae race 1 and Nec. haematococca MPI. This phylogenetic species represents one of the two known biologically isolated populations to induce fruit rot of cucurbits (Mehl & Epstein 2007a). The other, F. solani f. sp. cucurbitae race 2 (Nec. haematococca MPV) falls within the circumscription of N. petroliphila, an important pathogen of plant and animal species, including humans (Mehl & Epstein 2007b, Short et al. 2013, Sandoval-Denis & Crous 2018).

Strains CBS 410.62 and CBS 616.66 studied here were previously identified as F. ensiforme. They do not morphologically match with the features of that species, nor cluster within the ‘ensiforme-clade’ sensu Nalim et al. (2011). In contrast, several studies link this clade with Nec. haematococca MPI (O’Donnell 2000, O’Donnell et al. 2008). Records indicate that strain CBS 616.66 is able to produce perithecia when crossed with isolates of F. solani f. cucurbitae race 1 from the collection of W.C. Snyder, while isolate NRRL 22153 (Table 1) is derived from a white perithecial strain reported by W.C. Snyder for this biological species (Snyder et al. 1975).

Morphologically, N. cucurbitae can easily be identified by its long, rather narrow sporodochial conidia with elongated apical and foot cells, and for its cylindrical, commonly flat-based aerial macroconidia. Similarly sized sporodochial conidia, with comparable septation can also be seen in N. mori. In the latter species, however, the sporodochial conidia are almost straight and markedly tapered, while aerial macroconidia are absent.

Neocosmospora cyanescens (G.A. de Vries et al.) Summerb. et al., Biology of Microfungi (Cham): 183. 2016

Basionym. Phialophora cyanescens G.A. de Vries et al., Antonie van Leeuwenhoek 50: 150. 1984.

Synonym. Cylindrocarpon cyanescens (G.A. de Vries et al.) Sigler, J. Clin. Microbiol. 29: 1858. 1991.

Typus. Netherlands, Groningen, subcutaneous tissue of the right foot of a male human patient, unknown date, Acad. Ziekenhuis Groningen, No. 689b (holotype CBS 518.82, maintained as a permanently metabolically inactive culture).

Descriptions & Illustrations — De Vries et al. (1984), Zoutman & Sigler (1991).

Additional material examined. Netherlands, Groningen, subcutaneous tissues of the right foot of a male human patient, unknown date, Acad. Ziekenhuis Groningen No. 689b, CBS 637.82.

Notes — Neocosmospora cyanescens, representing phylogenetic species FSSC 27, is an extremely rare and pleomorphic species. Its morphological characters render it hard to place in Neocosmospora, being characterised by forming aggregates of chlamydospore-like cells and sparse ellipsoidal conidia formed on long phialides. This species was originally isolated from a white-grain mycetoma in a man, initially described as a new species in Phialophora (De Vries et al. 1984), and then recombined in Cylindrocarpon, although multiseptate conidia are not produced (Zoutman & Sigler 1991). Based on DNA sequence data, this species was recently reallocated to Neocosmospora with the odd morphological features being attributed to years enduring extreme conditions in the host (Summerbell & Scott 2016). Neocosmospora cyanescens is only known from a single collection, the additional isolate CBS 637.82 being a white mutant from the original collection.

Neocosmospora diminuta Sand.-Den. & Crous, sp. nov. — MycoBank MB831180; Fig. 14

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Fig. 14.

Neocosmospora diminuta (ex-type culture CBS 144390). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–d. perithecia; e. detail of the peridium cells; f–g. asci; h–j. ascospores; k–n. aerial conidiophores; o–p. aerial microconidia; q. chlamydospores; r. aerial macroconidia. — Scale bars: c–d = 100 μm; i–j = 5 μm; k–n = 20 μm; all others = 10 μm.

Etymology. From Latin diminuto meaning ‘minute, tiny’; refers to its small conidia.

Typus. Unknown (presumptively Ivory Coast), from Coelocaryon preussii treated wood, before 1972, Centre Technique Forestier Tropical (holotype CBS H-23979 designated here, culture ex-type CBS 144390 = MUCL 18798).

Perithecia orange to dark-red, globose to pyriform, papillate, superficial, solitary or gregarious, coarsely warted, glabrous; peridial wall composed of thick-walled cells of textura angularis. Asci subcylindrical, clavate to saccate, unitunicate, apex rounded and simple, (59.5–)62.5–74.5(–82.5) × (7.5–)8–11(–11.5) μm (av. 68.6 × 9.5 μm, n = 48). Ascospores obliquely uniseriate or irregularly biseriate at apex of asci, ellipsoidal to subfusiform, 1-septate, (9–)10.5–12(–14.5) × (4–)4.5–5.5(–6) μm (av. 11.2 × 5.1 μm, n = 99), yellow-brown to golden yellow, thick-walled, longitudinally finely striated.

Conidiophores abundant on aerial mycelium or erect from substrate mycelium, straight or flexuous, smooth- and thin-walled, simple or branched several times verticillately or sympodially, bearing terminal monophialides; phialides subulate to subcylindrical, (8.5–)36.5–56.5(–69) × (1.5–)2–3 μm (av. 46.4 × 2.4 μm, n = 72), smooth- and thin-walled, proliferating frequently, conidiogenous loci with periclinal thickening and a short, non-flared collarette; aerial conidia of two types: microconidia oval to ellipsoidal, straight or slightly curved, 0(–1)-septate, hyaline, smooth- and thin-walled, (4–)5–8.5(–14.5) × 2–3.5(–4.5) μm (av. 6.6 × 2.8 μm, n = 108), clustering in false heads at tip of monophialides; macroconidia short falcate and multiseptate, gently dorsiventrally curved with almost straight ventral line, base rounded, inconspicuously or distinctly notched, 1–3-septate, smooth- and thick-walled; 1-septate conidia: (14.5–)17.5–22.5 × (3.5–)4–5 μm (av. 19.9 × 4.4 μm, n = 29); 2-septate conidia: 21–24(–24.5) × 3.5–4.5 μm (av. 22.4 × 4.1 μm, n = 5); 3-septate conidia: (22.5–)27–35(–38) × 4–5(–5.5) μm (av. 31.1 × 4.7 μm, n = 52); overall: (14.5–)20.5–33.5(–38) × (3.5–)4–5(–5.5) μm (av. 26.8 × 4.5 μm, n = 86). Sporodochia not observed. Chlamydospores subglobose to globose, smooth- and thick-walled, (6–)7–10.5(–11) μm diam, solitary or in chains.

Colonies on PDA growing in dark with an average radial growth rate of 4–4.8 mm/d at 24 °C, reaching 56–70 mm diam in 7 d at 24 °C; luteous to ochreous, flat, velvety to felty, with or without concentric rings of short aerial mycelium; margin entire. Reverse pale luteous to orange. On OA incubated in dark reaching 50–57 mm diam in 7 d at 24 °C; salmon to flesh with abundant white mycelium at centre, flat, velvety to floccose; margin entire. Reverse peach, salmon to flesh.

Notes — Previously known as phylogenetic species FSSC 39, this clade was recognised as a putative novel species during a screening for human pathogenic fusaria in plumbing drains, but not formally described based on its cryptic morphology (Short et al. 2011). Neocosmospora diminuta produces the smallest falcate multiseptate conidia in the genus. These macroconidia are not produced on sporodochia, but on tall aerial conidiophores, mixed with microconidia.

Morphologically, N. diminuta is comparable to N. brevis, with both species lacking sporodochia and producing short, multiseptate, aerial falcate conidia. Conidia of N. diminuta, are considerably smaller and less septate (up to 14.5 μm long, av. size 11.2 × 5.1 μm and 1–3-septate, vs up to 52.5 μm long, av. size 37.5 × 5.7 μm and 3–5-septate in N. brevis). In addition, N. diminuta has a conspicuous sexual morph, while an asexual morph is not known for N. brevis.

Other species with similarly sized macroconidia are N. keratoplastica and the unnamed phylogenetic species FSSC 12 (not yet formally introduced, D. Geiser pers. comm.). In the latter species macroconidia are produced on well-developed sporodochia.

Neocosmospora elegans (Y. Yamam. & Maeda) Sand.-Den. & Crous, comb. nov. — MycoBank MB831226; Fig. 15

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Fig. 15.

Neocosmospora elegans (ex-epitype culture CBS 144396). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–e. perithecia; f. detail of peridium cells; g. sporodochia formed on the surface of carnation leaves; h–k. asci; l–n. ascospores; o–p. chlamydospores; q–t. aerial conidiophores and phialides; u–v. aerial conidia; w. sporodochial phialide; x. sporodochial conidia. — Scale bars: c–e, g = 100 μm; h–i, q–s = 20 μm; m–n, v–w = 5 μm; all others = 10 μm.

Basionym. Nectria elegans Y. Yamam. & Maeda, Sci. Rep. Hyogo Univ. Agric. 3: 15. 1957.

Synonyms. (Fusarium solani f. xanthoxyli Y. Sakurai & Matuo, Ann. Phytopathol. Soc. Japan 26: 117. 1961 (Nom. inval., Art. 39.1.)).

(Hypomyces solani f. xanthoxyli Y. Sakurai & Matuo, Ann. Phytopathol. Soc. Japan 26: 117. 1961 (Nom. inval., Art. 39.1.)).

Typus. Japan, Prov. Tamba, Nishiki-mura, on twigs and trunks of Xanthoxylum piperitum (lectotype of Nectria elegans, designated here: illustration f. 1–9, p. 16, in Yamamoto et al. (1957), Science Reports of the Hyogo University of Agriculture. 3: 15–18, MBT387213); Hyōgo, from trunk of X. piperitum, 1959, Y. Sakurai (epitype of N. elegans CBS H-23980 designated here, MBT387214; culture ex-epitype CBS 144396 = NRRL 22277 = MAFF 238541 = ATCC 42366 = SUF XV-1).

Perithecia dark-orange to dark-red, globose, subglobose or pyriform, superficial or partially embedded in substrata, solitary or gregarious, coarsely warted, glabrous; peridial wall composed of thick-walled cells of textura angularis. Asci subcylindrical to clavate, unitunicate, apex flat to rarely rounded and simple, (68.5–)70–85.5(–94) × (7.5–)8–10 μm (av. 76.8 × 9.1 μm, n = 48). Ascospores obliquely uniseriate or irregularly biseriate at apex of asci; broadly ellipsoidal to ellipsoidal, 1-septate, (9–)10.5–12.5(–14) × 4–5.5(–6.5) μm (av. 11.6 × 4.9 μm, n = 132), pale yellow-brown to golden yellow, thick-walled, longitudinally finely to coarsely striated, often rounded at both ends and constricted at septum.

Conidiophores erect and prostrate on substrate mycelium, abundantly produced on aerial mycelium, straight, smooth- and thin-walled, often short and simple, reduced to conidiogenous cells borne laterally on hyphae, or sparingly branched irregularly, verticillately or sympodially, bearing terminal and lateral, single monophialides; phialides subulate, subcylindrical to acicular, (28.5–)36–53(–63) × 2–3.5(–5) μm (av. 44.5 × 2.8 μm, n = 104), smooth- and thin-walled, walls sometimes slightly thickened at base, conidiogenous loci with rather conspicuous periclinal thickening, collarettes short- and non-flared or absent; aerial conidia ellipsoidal to clavate, straight, rarely slightly curved, 0(–1)-septate, hyaline, smooth- and thin-walled, (5–)6–7(–16) × (1.5–)2–3.5(–4.5) μm (av. 8 × 2.9 μm, n = 129). Sporodochia cream to olivaceous. Sporodochial conidiophores sparingly irregularly or verticillately branched, bearing terminal, single monophialides; sporodochial phialides subcylindrical to subulate, (12–)13.5–17.5(–18) × 2–3.5 μm (av. 15.3 × 2.9 μm, n = 80), smooth- and thin-walled, conidiogenous loci with inconspicuous periclinal thickening and collarettes. Sporodochial conidia discreetly dorsiventrally curved, often more pronouncedly curved in bottom half of the conidia; broad in middle portion or just above it and narrowing gradually toward both ends; apical cell often longer than the adjacent cell, blunt to conical with a discreetly curved, rounded apex; basal cell blunt and straight or notched, (3–)5–6-septate, hyaline, smooth- and thick-walled; 3-septate conidia: 35.5 × 4 μm (n = 2); 5-septate conidia: (50.5–)57–66.5(–70) × (4.5–)5–6(–6.5) μm (av. 61.8 × 5.4 μm, n = 76); 6-septate conidia: (63–)65.5–75(–78.5) × 5–6 μm (av. 70.1 × 5.5 μm, n = 34); overall: (34.5–)56.5–71(–78.5) × (4–)5–6(–6.5) μm (av. 63.8 × 5.4 μm, n = 112). Chlamydospores abundant, globose to subglobose, smooth- and thick-walled, 8.5–11(–12.5) μm diam, turning pale golden yellow when mature; terminal or intercalary, solitary, in chains or clusters.

Colonies on PDA growing in dark with an average radial growth rate of 2.3–3 mm/d at 24 °C, reaching 31–40 mm diam in 7 d at 24 °C; straw to pale luteous coloured, flat, velvety to felty, with abundant white aerial mycelium; margin entire. Reverse straw to pure yellow. On OA incubated in dark reaching 34–42 mm diam in 7 d at 24 °C; cream, straw to pale buff coloured, flat, velvety to granular, with concentric rings of white to cream aerial mycelium; margin entire. Reverse straw to buff.

Additional material examined. Japan, Hyōgo, from a branch of Xanthoxylum piperitum, 1959, Y. Sakurai, CBS 144395 = NRRL 22163 = MAFF 238540 = ATCC 18690 = MATUO XV-23.

Notes — This species was initially described as the causal agent of trunk-blight of Xanthoxylum piperitum in Japan (Yamamoto et al. 1957), with the sexual morph placed in Nectria. The asexual morph was assigned to Fusarium sect. Elegans (F. oxysporum s.lat.), but was later re-identified by Sakurai & Matuo (1961) as F. solani, and reduced to a formae speciales of the latter taxon (as F. solani f. xanthoxyli), and the sexual morph recombined into the genus Hypomyces (as Hyp. solani f. sp. xanthoxyli). However, sexual incompatibility (Matuo & Snyder 1973), phylogenetic inference (O’Donnell 2000, O’Donnell et al. 2008), and RAPD and ITS-RFLP banding patterns (Hering 1997) demonstrated that this taxon is not conspecific with N. solani. Therefore, it has been informally assigned to F. solani f. sp. xanthoxyli and later to phylogenetic species FSSC 22 (O’Donnell 2000). Accordingly, the basionym is resurrected here and recombined as Neocosmospora elegans. The two heterothallic strains studied here formed part of the mating studies by Sakurai & Matuo (1961) and are able to reproduce sexually in vitro.

Type material of N. elegans could not be traced; the current location of the type specimen cited in the protologue (Japan, Prov. Tamba, Nishiki-mura, on twigs and trunks of X. piperitum, 16 Sept. 1955, W. Yamamoto) is unknown and is therefore presumed lost (C. Nakashima & Y. Hirooka, pers. comm.). A living strain identified by W. Yamamoto is housed in NBRC (NBRC 7187 = IFO 7187), however, not as type. In order to fix the use of the name, a lectotype is designated from the original illustration, which is reproduced here (Fig. 16) and an epitype is chosen from material obtained from the same geographical region (prefecture) where the holotype was originally collected.

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Fig. 16.

Neocosmospora elegans (lectotype of Nectria elegans) adapted from the original drawings by Yamamoto et al. (1957). a. Asci; b. ascospores; c. sporodochial conidia; d–f. chlamydospores; g–h. aerial conidia; i. sclerotium.

An unusual characteristic of this species is the presence, although rare, of short rather ampulliform aerial phialides born laterally on the hyphae, which somehow resemble those of F. oxysporum s.lat. Nevertheless, the most commonly formed conidiogenous apparatus corresponds to the archetypal F. solani/Neocosmospora type.

Species showing similar dimensions of sporodochial macroconidia include N. hypothenemi and N. silvicola. Neocosmospora elegans can be distinguished by its regularly sparingly branched conidiophores, the luteous coloration of its colonies and its narrow (av. width 2.9 μm) microconidia. In contrast, N. hypothenemi and N. silvicola form highly branched, tall conidiophores; orange to scarlet colonies in the former and saffron in the latter, and wider microconidia (av. width of 3.9 μm and 3.7 μm for N. hypothenemi and N. silvicola, respectively). In addition, N. hypothenemi lacks a known sexual morph.

Neocosmospora euwallaceae (S. Freeman et al.) Sand.-Den., L. Lombard & Crous, comb. nov. — MycoBank MB831181

Basionym. Fusarium euwallaceae S. Freeman, Z. Mendel, T. Aoki & O’Donnell, Mycologia 105: 1599. 2013.

Typus. Israel, Kibbutz Glil Yam central coastal region, Euwallacea sp. beetle infecting Persea americana (cultivar Hass), 17 Feb. 2010, S. Freeman & Z. Mendel (Freeman 1) (holotype BPI 884203; culture ex-type CBS 135854 = NRRL 54722).

Description & Illustration — Freeman et al. (2013).

Notes — A member of the Ambrosia clade of Neocosmospora, it is also referred to as Clade AF2 (Freeman et al. 2013) and is a serious threat to avocado production in Israel and California (Mendel et al. 2012, Eskalen et al. 2013, O’Donnell et al. 2016). It was recently introduced into South Africa where c. 80 tree host species have been identified, including native and exotic trees (Paap et al. 2018, retrieved from www.fabinet.up.ac.za/index.php/pshb on April 2019). Neocosmospora euwallaceae is clearly recognisable by its blue-brown, irregularly clavate sporodochial conidia (see notes under N. ambrosia).

A draft genome sequence was recently published of a strain regarded as N. euwallaceae (as Fusarium euwallaceae strain HFEW-16-IV-019; Ibarra-Laclette et al. 2017), and, rDNA, tef1 and rpb2 sequences were retrieved from the genome scaffolds available in GenBank and included in this study (Table 1, Fig. 1). The results indicate that the reported genome sequences belong to a different, although closely related species, N. kuroshio (see below). This is also supported by the host insect association reported for that strain (Kuroshio shot hole borer beetle, Euwallacea sp. nr. fornicatus #5, KSHB; O’Donnell et al. 2015, Stouthamer et al. 2017, Na et al. 2018).

Neocosmospora falciformis (Carrión) L. Lombard & Crous, Stud. Mycol. 80: 227. 2015

Basionym. Cephalosporium falciforme Carrión, Mycologia 43: 523. 1951.

Synonyms. Acremonium falciforme (Carrión) W. Gams, Cephalosporium-artige Schimmelpilze (Stuttgart): 139. 1971.

Fusarium falciforme (Carrión) Summerb. & Schroers, J. Clin. Microbiol. 40: 2872. 2002.

Fusarium paranaense Costa, Matos & Pfenning, Fungal Biol. 120: 55. 2017.

Typus. Puerto Rico, from a human mycetoma, 1967, J.E. MacKinnon (holotype CBS 475.67, permanently preserved as metabolically inactive culture, culture ex-type CBS 475.67 = IHM 939 = IMI 268681).

Descriptions & Illustrations — Carrión (1951), Gams (1971), Costa et al. (2016), Sandoval-Denis & Crous (2018).

Additional materials examined. Brazil, Distrito Federal, Brasília, from Glycine max, unknown date and collector, CBS 141594 = CML 860 (culture ex-paratype of F. paranaense); Goiás, Cristalina, from basal stem of Glycine max, Feb. 2000, collector unknown, CBS 141593 = CML 1830 = MES 24 (culture ex-type of F. paranaense). – France, Nancy, human nail, unknown date, N. Contet-Audonneau, CBS 124627. – Syria, declined grapevine, unknown date, K.A. Halim, CBS 121450.

Notes — Also known as phylogenetic species FSSC 3+4 (O’Donnell et al. 2008), N. falciformis is one of the most prevalent clinically relevant species of the genus along with N. keratoplastica, N. metavorans, N. petroliphila and N. solani (Short et al. 2013, Sandoval-Denis & Crous 2018). These species are opportunistic taxa, capable of inducing disease in humans and other animals (O’Donnell et al. 2008, 2016, Sarmiento-Ramírez et al. 2014, Sandoval-Denis & Crous 2018), with some also found as weak plant pathogens (Short et al. 2011, 2013, Scheel et al. 2013). It is one of the most frequently encountered species from natural substrates.

The ex-type and ex-paratype cultures of Fusarium paranaense (CBS 141593 and CBS 141594, respectively), a recently published species responsible for root rot of Glycine max in Brazil (Costa et al. 2016), cluster within the main clade of N. falciformis, and this species is thus here reduced to synonymy under N. falciformis. Interestingly, F. paranaense was described with a sexual morph, a feature previously not known for N. falciformis, and that indicates the existence of a heterothallic sexual cycle in the latter taxon.

The presence of sporodochial macroconidia is largely strain dependant in N. falciforme. The ex-type strain, CBS 475.67, is known to exhibit a microconidial morphology, lacking typical falcate multiseptate conidia, which explains its original allocation in Cephalosporium and later in Acremonium (Carrión 1951, Gams 1971). When present, sporodochial conidia are rather short and bulky, similar in size and appearance to those of N. metavorans and N. solani. In N. falciformis, sporodochial conidia are less septate, shorter and narrower, while aerial conidia are larger than those of N. metavorans (Sandoval-Denis & Crous 2018). In contrast, the sporodochial conidia of N. metavorans and N. solani tend to be more clearly tapered.

Neocosmospora ferruginea Sand.-Den. & Crous, sp. nov. — MycoBank MB831182; Fig. 17

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Fig. 17.

Neocosmospora ferruginea (ex-type culture CBS 109028). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–d = sporodochia formed on the surface of carnation leaves; e. pseudostromatic structures; f–i. aerial conidiophores; j, aerial conidia; k. chlamydospores; l–m. sporodochial conidiophores and phialides; n–o. sporodochial conidia. — Scale bars: c–d = 100 μm; e = 20 μm; all others = 10 μm.

Etymology. From Latin ferrugineus (‘rust colour’). Referring to the colony colour on artificial media.

Typus. Switzerland, from human subcutaneous nodule, unknown date, G. Schär (holotype CBS H-23981 designated here, culture ex-type CBS 109028 = NRRL 32437).

Conidiophores abundant on aerial mycelium, commonly borne from dense mycelial tufts or cords, or emerging on agar surface from pseudostromatic structures composed of pale brown, irregularly shaped, smooth- and thick-walled cells; straight, smooth- and thin-walled, simple or sparingly branched verticillately or irregularly, bearing terminal, single monophialides; phialides subulate, subcylindrical to acicular, (29.5–)31–40(–45) × 2.5–3.5 μm (av. 35.5 × 3 μm, n = 96), hyaline to subhyaline when mature, smooth- and thick-walled, conidiogenous loci with inconspicuous periclinal thickening, collarettes absent or minute; aerial conidia ellipsoidal to allantoid, 0–1(–2)-septate, hyaline, smooth- and thin-walled, (4–)4.5–11(–20) × (1.5–)2–4(–6) μm (av. 7.6 × 3 μm, n = 92), clustering in false heads at tip of monophialides. Sporodochia white to buff. Sporodochial conidiophores irregularly and verticillately branched and densely packed; sporodochial phialides subcylindrical to doliiform, 16.5–22(–24.5) × 3.5–4.5(–5) μm (av. 19.4 × 4.1 μm, n = 42), smooth- and thin-walled, conidiogenous loci with inconspicuous periclinal thickening, without collarette or with a short, non-flared collarette. Sporodochial conidia moderately curved, gently tapered and straighten toward base; apical cell of equal length than adjacent cell, blunt to conical, with a somewhat constricted, barely hooked and rounded apex; basal cell distinctly notched, often protuberant, (4–)5–6(–7)-septate, hyaline, smooth- and thick-walled; 4-septate conidia: 53.5–57.5 × 5–5.5 μm (av. 55.6 × 5.3 μm, n = 6); 5-septate conidia: (55.5–)58.5–67(–70) × (5–)5.5–6(–6.5) μm (av. 62.4 × 5.7 μm, n = 72); 6-septate conidia: (56.5–)61.5–69.5(–71.5) × 5–6.5 μm (av. 65.4 × 5.7 μm, n = 33); 7-septate conidia: 69.5 × 6 μm (n = 3); overall: (54–)58–69(–71.5) × 5–6.5 μm (av. 63.1 × 5.7 μm, n = 114). Chlamydospores globose to subglobose, smooth- and thick-walled, 8–10 μm diam, terminal or intercalary, solitary or in short chains.

Colonies on PDA growing in dark with an average radial growth rate of 2–2.5 mm/d at 24 °C, reaching 27–30 mm diam in 7 d at 24 °C; sienna, rust to brick, flat, velvety, margin entire. Reverse apricot to rust. Colonies on OA incubated in dark reaching 23–28 mm diam in 7 d at 24 °C; peach to rosy buff, flat, velvety to dusty, margin entire. Reverse saffron to rosy buff.

Additional materials examined. Italy, from Citrus sinensis, 3 Mar. 2015, V. Guarnaccia, CPC 28194, CPC 28195.

Notes — Previously known as phylogenetic species FSSC 28, Neocosmospora ferruginea was assigned to the ‘F. ensiforme clade’ by Nalim et al. (2011). This group encompass an array of phylogenetic species with morphologies comparable to that of F. ensiforme (F. javanicum var. ensiforme). The latter species is characterised by producing long, somewhat straight and acute sporodochial conidia with protuberant foot cells (Wollenweber & Reinking 1925, 1935a, Gerlach & Nirenberg 1982). Although largely resembling the historical concept of F. ensiforme, N. ferruginea differs in various aspects that include conidial dimensions, forming shorter, rarely 7-septate sporodochial conidia with rounded and hooked apices, and wider microconidia (up to 6 μm vs up to 4 μm wide in F. ensiforme). In addition, N. ferruginea forms rust-coloured colonies on PDA, contrary to the white to pink colonies of F. ensiforme. The presence of pseudostromatic structures in N. ferruginea could be considered a differential character. However, this feature was observed only in the ex-type isolate.

Several species share similar morphological features with N. ferruginea, particularly those previously assigned to the ‘F. ensiforme clade’ (Nalim et al. 2011), i.e., N. hypothenemi, and N. spathulata, but also genetically unrelated species like N. piperis and N. protoensiformis. These taxa produce similarly shaped and relatively large, up to 6- or rarely 7-septate sporodochial conidia. Nevertheless, N. ferruginea differs from N. piperis by the absence of aerial macroconidia and sexual morph in the former species. Neocosmospora hypothenemi, N. protoensiformis and N. spathulata differ by exhibiting sporodochial conidia with tapered, somewhat acute and straight apical cells, and protuberant foot cells vs the rounded and hooked apical cells and less developed foot cells of N. ferruginea.

Neocosmospora gamsii Sand.-Den. & Crous, Persoonia 41: 116. 2018

Typus. USA, Pennsylvania, from human bronchoalveolar lavage fluid, unknown date, D.A. Sutton (holotype CBS H-23226, culture ex-type CBS 143207 = NRRL 32323 = UTHSC 99-205).

Description & Illustration — Sandoval-Denis & Crous (2018).

Additional materials examined. Brazil, unknown substrate, date and collector, CBS 700.86 = NRRL 22236. – Nigeria, from plywood, unknown date and collector, CBS 217.53 = NRRL 22655. – USA, Illinois, Urbana, human eye, unknown date and collector, CBS 143209 = NRRL 32770 = FRC S-0524; New York, coolant fluid from humidifier, unknown date and collector, CBS 143211 = NRRL 32794 = FRC S-1152; Tennessee, human cornea, unknown date and collector, CBS 130181 = NRRL 43502 = CDC 2006743469.

Notes — A name recently proposed for the previously informally known phylogenetic species FSSC 7 (O’Donnell et al. 2008, Sandoval-Denis & Crous 2018), N. gamsii is a pathogenic species known mostly from human clinical samples. This species is isolated with lesser frequency than the more prevalent pathogenic species N. keratoplastica, N. metavorans, N. petroliphila and N. solani. Among the clinically relevant species of the genus, N. gamsii is recognisable by having long and narrow sporodochial conidia with elongated, curved and rounded apical cells and a conspicuous homothallic sexual morph (Sandoval-Denis & Crous 2018).

Morphologically, it is a close ally to N. ampla and N. elegans. The latter species are presently only known from plant hosts. Nonetheless, a number of features distinguish N. gamsii, including its narrow sporodochial conidia with elongated, hooked and rounded apical cells, smaller microconidia (up to 11 μm long vs up to 16 and 23 μm long, respectively for N. elegans and N. ampla), sporodochia being yellow-blue-green at maturity (vs cream to olivaceous in N. ampla and N. elegans), the presence of a sexual morph (absent in N. ampla) and the absence of aerial macroconidia (present in N. ampla; Sandoval-Denis & Crous 2018).

Neocosmospora haematococca (Berk. & Broome) Samuels et al., Mycologia 103: 1322. 2011

Basionym. Nectria haematococca Berk. & Broome, J. Linn. Soc., Bot. 14: 116. 1875.

Synonyms. Dialonectria haematococca (Berk. & Broome) Cooke, Grevillea 12: 110. 1884.

Cucurbitaria haematococca (Berk. & Broome) Kuntze, Revis. Gen. Pl. 3: 461. 1898.

Hypomyces haematococcus (Berk. & Broome) Wollenw., Angew. Bot. 8: 191. 1926.

Haematonectria haematococca (Berk. & Broome) Samuels & Nirenberg, Stud. Mycol. 42: 135. 1999.

Fusarium haematococcum Nalim et al., Mycologia 103: 1322. 2011.

?Nectria lanata Pat., Bull. Soc. Mycol. France 8: 52. 1892 (fide Samuels 1976).

?Nectria aurantiella Speg., Anales Mus. Nac. Hist. Nat. Buenos Aires 6: 287. 1898 (fide Samuels 1976).

?Nectria episphaerioides Penz. & Sacc., Malpighia 11: 511. 1898 (fide Samuels 1976).

?Nectria cinnabarina var. jaraguensis Höhn., Denkschr. Kaiserl. Akad. Wiss., Wien. Math.-Naturwiss. Kl. 83: 18. 1907 (fide Rossman et al. 1999).

?Nectria victoriae Henn., Ann. Mycol. 5: 81. 1907 (fide Samuels 1976).

?Nectria calonectricola Henn., Hedwigia 48: 105. 1908 (fide Rossman et al. 1999).

?Nectria citri Henn., Hedwigia 48: 104. 1908 (fide Samuels 1976).

?Nectria luteococcinea Höhn., Sitzungsber. Kaiserl. Akad. Wiss., Math.-Naturwiss. Cl., Abt. 1. 118: 299. 1909 (fide Rossman et al. 1999).

?Nectria bainii var. hypoleuca Sacc., Nuovo Giorn. Bot. Ital. 23: 205. 1916 (fide Samuels 1976).

?[Nectria confluens Seaver, Sci. Surv. Porto Rico & Virgin Islands 8: 44. 1926 (Nom. illegit., Art. 53.1) (fide Rossman et al. 1999)].

?Nectria bogoriensis C. Bernard, Bull. Dépt. Agric. Indes Néerl. 11: 45. 1907 (fide Samuels 1976, Rossman et al. 1999).

Typus. Sri Lanka, Ceylon, Central Province, on bark, 1868, G.H.K. Thwaites no. 1104, (lectotype of Nectria haematococca K(M) 252877, designated by Samuels (1976)); Sabaragamua, Singaharaj Man and Biosphere Reserve, Morningside, vicinity Bungalow in forested slope, on dying tree, 10 Dec. 2002, G.J. Samuels, A. Nalim, N. Dayawansa, K. Poldmaa (epitype of Nectria haematococca BPI 871363, designated by Nalim et al. (2011), culture ex-epitype CBS 119600 = FRC S-1832).

Descriptions & Illustrations — Samuels (1976), Rossman et al. (1999), Samuels et al. (2006), Nalim et al. (2011).

Notes — Many of the synonyms listed in Samuels (1976) and Rossman et al. (1999) are here listed as doubtful. Neocosmospora haematococca was recently epitypified and confined to a discrete phylogenetic lineage (Nalim et al. 2011). Therefore, the list of synonyms certainly needs to be re-evaluated according to the wide genetic diversity derived from recent phylogenetic evidence, contrasting with the morphologically broad and polyphyletic traditional concept of Nec. haematococca.

Neocosmospora hengyangensis Z.Q. Zeng & W.Y. Zhuang, Phytotaxa 319: 179. 2017

Typus. China, Hunan, Hengyang, Gouloufeng, on twigs, 24 Oct. 2015, Z.Q. Zeng, X.C. Wang, K. Chen, Y.B. Zhang (holotype HMAS 254518, culture ex-type HMAS 254518).

Description & Illustration — Zeng & Zhuang (2017).

Notes — A recently described taxon and one of the five Neocosmospora sexual species so far known from China (Zeng & Zhuang 2017). Only DNA sequences were available to us for this species. Molecular data indicate that this is a well-resolved species, nested within a discrete lineage which includes closely related taxa with known sexual morphs, i.e., N. bataticola, N. brevicona, N. elegans and N. hengyangensis. Morphological features of the asexual morph, as described in the protologue of N. hengyangensis, clearly differentiate this species from its closest phylogenetic relative N. bataticola, the former species lacking aerial macroconidia (present in N. bataticola) and possessing markedly smaller sporodochial conidia (4–6-septate, up to 60 μm long vs up to 8-septate and 101.5 μm long in N. bataticola).

Neocosmospora hypothenemi Sand.-Den. & Crous, sp. nov. — MycoBank MB831183; Fig. 18

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Fig. 18.

Neocosmospora hypothenemi (ex-type culture CBS 145464). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–f. sporodochia formed on the surface of carnation leaves; g–j = aerial conidiophores; k–l. aerial conidia; m–o. sporodochial conidia and phialides; p–q. sporodochial conidia. — Scale bars: c = 100 μm; d–f = 50 μm; g–i = 20 μm; l–m = 5 μm; all others = 10 μm.

Etymology. Name refers to the host genus Hypothenemus (Coleoptera: Scolytidae) from which this fungus was isolated.

Typus. Benin, Niaouli, from adult Hypothenemus hampei, unknown date and collector (holotype CBS H-23982 designated here, culture ex-type CBS 145464 = NRRL 52782 = ARSEF 5878).

Conidiophores erect on substrate mycelium, highly abundant on aerial mycelium, straight or flexuous, smooth-walled or finely verruculose and thin-walled, rarely simple, often copiously branched sympodially and verticillately, bearing terminal, single monophialides; phialides subulate to subcylindrical, (35–)45.5–55.5(–60) × 2–3.5(–4) μm (av. 50.6 × 2.8 μm, n = 102), smooth- and thin-walled, conidiogenous loci with periclinal thickening and a short-, non-flared collarette; aerial conidia ellipsoidal to cylindrical, with or without a slightly protruding base, straight or discreetly curved, 0-septate, hyaline, smooth- and thin-walled, (5.5–)6.5–10(–13.5) × (2.5–)3–4.5(–5) μm (av. 8.2 × 3.6 μm, n = 96), clustering in false heads at tip of monophialides. Sporodochia cream, ochreous to pale citrine. Sporodochial conidiophores densely verticillately branched and packed, bearing terminal, single monophialides or whorls of up to four phialides; sporodochial phialides subcylindrical to ampulliform, (8.5–)11.5–16.5(–21) × (2.5–)3.5–4.5(–5.5) μm (av. 14.1 × 3.9 μm, n = 110), smooth- and thin-walled, conidiogenous loci with inconspicuous periclinal thickening and collarettes. Conidia in sporodochia, moderately dorsiventrally curved to almost straight, somewhat strongly curved at both ends and tapering toward base; apical cell elongated, of equal length to the adjacent cell, blunt with a rounded and curved apex; basal cell elongated and distinctly notched, often protuberant, (2–)3–6(–7)-septate, hyaline, smooth- and thick-walled; 2-septate conidia: 24 × 4.5 μm (n = 3); 3-septate conidia: (29–)33–44.5(–46) × 4.5–5 μm (av. 39.5 × 4.8 μm, n = 12); 4-septate conidia: (40–)43.5–53(–56.5) × (4–)4.5–5.5(–6) μm (av. 48.3 × 4.9 μm, n = 75); 5-septate conidia: (47.5–)55–63 (–66.5) × (4.5–)5–5.5 μm (av. 59 × 5.1 μm, n = 273); 6-septate conidia: (60–)61–64(–65) × (4.5–)5.5–6 μm (av. 62.6 × 5.2 μm, n = 33); overall: (24–)49–64(–66.5) × (4–)4.5–5.5(–6) μm (av. 56.4 × 5.1 μm, n = 399). Chlamydospores globose to subglobose, smooth- and thick-walled, 5.5–10 μm diam, terminal or intercalary, solitary or in short chains.

Colonies on PDA growing in dark with an average radial growth rate of 3.2–4.2 mm/d at 24 °C, reaching 45–63 mm diam in 7 d at 24 °C; white, pale luteous to saffron, flat, felty to granulose, with abundant white aerial mycelium in a radiate and concentric arrangement; margin entire. Reverse saffron, orange to rust, often with abundant scarlet to rust diffusible pigment. On OA incubated in dark covering an entire 90 mm Petri dish in 7 d at 24 °C; white to pale ochreous, flat, velvety to granulose; margin entire. Reverse pale luteous, buff to pale rust.

Additional material examined. Uganda, Chesogok, from adult H. hampei, unknown date and collector, CBS 145466 = NRRL 52783 = ARSEF 5879.

Notes — Previously known as phylogenetic species FSSC 38, N. hypothenemi is described associated with the coffee borer beetle or coffee berry borer (Hypothenemus hampei: Curculionidae: Scolytinae). It is phylogenetically distant and unrelated to the main cluster of arthropod symbiont species of the Ambrosia clade. Neocosmospora hypothenemi also retains the typically shaped falcate sporodochial conidia of Neocosmospora, contrasting with the irregular, asymmetrical-clavate conidia of the most important beetle-associated pathogens in the Ambrosia clade (Aoki et al. 2018). This is most likely a reflection of the non-symbiont nature of this species.

Morphologically, N. hypothenemi is different from its closest phylogenetic relatives, N. perseae and N. pseudoradicicola. Both N. hypothenemi and N. perseae exhibit red coloured colonies on PDA. However, in the former species these are saffron coloured instead of bright red as observed in N. perseae. In addition, N. hypothenemi produces highly branched aerial conidiophores and its sporodochial conidia are slender, relatively long (up to 66.5 μm long) with elongated apical and basal cells, contrasting with the simpler conidiophores of N. perseae and the latter’s shorter (up to 55.5 μm long) and more robust sporodochial conidia. Neocosmospora pseudoradicicola is morphologically differentiated by its short, less septate, curved and apically hooked conidia and the presence of a microcyclic conidiogenous cycle. The morphologically close, although genetically distinct species N. spathulata, is almost indistinguishable from N. hypothenemi (see notes under N. spathulata).

Neocosmospora illudens (Berk.) L. Lombard & Crous, Stud. Mycol. 80: 227. 2015

Basionym. Nectria illudens Berk., Bot. Antarct. Voy. II (Fl. Nov.-Zeal.): 203. 1855.

Synonyms. Cucurbitaria illudens (Berk.) Kuntze, Revis. Gen. Pl. 3: 461. 1898.

Haematonectria illudens (Berk.) Samuels & Nirenberg, Stud. Mycol. 42: 136. 1999.

Fusarium illudens C. Booth, The Genus Fusarium: 54. 1971.

Typus. New Zealand, North Island, Bay Islands, on bark, J. Hooker (fide Samuels & Brayford 1994, not located).

Descriptions & Illustrations — Booth (1971), Gerlach & Nirenberg (1982), Samuels & Brayford (1994), Rossman et al. (1999).

Material examined. New Zealand, from Beilschmiedia tawa, unknown date or collector, NRRL 22090 = BBA 67606 = G.J.S 82-98.

Notes — This species is here represented by DNA sequences of a single isolate only, matching morphologically and geographically with the original description of the species. It is regarded as representative of N. illudens (Samuels & Brayford 1994, O’Donnell 2000, O’Donnell et al. 2008), although we could not confirm the existence of a type collection. Numerous specimens are housed at K marked as putative types; however, none match the collection data of the protologue. Similarly, Samuels & Brayford (1994) cited the holotype details but seemed unable to locate type material. Several specimens from New Zealand later collected by J.M. Dingley and G.J. Samuels are available in BPI and PDD, likely suitable to fix the application of the name if the holotype is confirmed lost.

The closely related species, N. plagianthi, clusters as a sister lineage to N. illudens and are the only known members of Neocosmospora Clade 1 (O’Donnell 2000). Both species are recognisable by several features of their sexual morphs and the absence of an asexual morph in N. plagianthi (Samuels & Brayford 1994, but see notes under N. plagianthi).

Descriptions of the asexual morph of N. illudens (as Fusarium illudens) by Booth (1971) and Samuels & Brayford (1994) indicate sporodochial conidia in the size and septation range of N. robusta and N. silvicola. Both these phylogenetically unrelated species nest within Clades 2 and 3 of Neocosmospora (sensu O’Donnell 2000), and can be distinguished by the absence of microconidia in N. robusta, while the aerial conidia in N. silvicola are much longer (up to 23.5 μm long vs up to 8 μm long in N. illudens; Booth 1971, Gerlach & Nirenberg 1982, Samuels & Brayford 1994).

Neocosmospora ipomoeae (Halst.) L. Lombard & Crous, Stud. Mycol. 80: 227. 2015. — Fig. 19

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Fig. 19.

Neocosmospora ipomoeae. a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–e. perithecia; f. detail of peridium cells; g. sporodochia formed on the surface of carnation leaves; h–j. asci; k–l. ascospores; m–q. aerial conidiophores; r. aerial conidia; s–t. sporodochial conidiophores and phialides; u. sporodochial conidia. — Scale bars: c–e, g = 100 μm; all others = 10 μm.

Basionym. Nectria ipomoeae Halst., Rep. (Annual) New Jersey Agric. Exp. Sta. 12: 281. 1891.

Synonyms. Cucurbitaria ipomoeae (Halst.) Kuntze, Revis. Gen. Pl. 3: 461. 1898.

Creonectria ipomoeae (Halst.) Seaver, N. Amer. Fl. 3: 22. 1910.

Hypomyces ipomoeae (Halst.) Wollenw., Phytopathology 3: 34. 1913.

Haematonectria ipomoeae (Halst.) Samuels & Nirenberg, Stud. Mycol. 42: 136. 1999.

Nectria ipomoeae f. ipomoeae Halst., Rep. (Annual) New Jersey Agric. Exp. Sta. 12: 281. 1891.

Nectria ipomoeae var. ipomoeae Halst., Rep. (Annual) New Jersey Agric. Exp. Sta. 12: 281. 1891.

Hypomyces ipomoeae var. ipomoeae (Halst.) Wollenw., Phytopathology 3: 34. 1913.

Hypomyces ipomoeae var. major Wollenw., Fusaria Autographice Delineata 3: 826. 1930.

?Fusarium striatum Sherb., Cornell Univ. Agric. Exp. Sta. Mem. 6: 255. 1915 (fide Nirenberg & Brielmaier-Liebetanz 1996).

?Fusarium solani var. striatum (Sherb.) Wollenw., Z. Parasitenk. (Berlin) 3: 451. 1931 (fide Nirenberg & Brielmaier-Liebetanz 1996).

Typus. USA, New Jersey, Mickelton, on Solanum melongena, 8 July 1891, B.D. Halsted (holotype BPI 552416).

Perithecia orange to dark-red, globose to pyriform, superficial, solitary or gregarious, coarsely warted, glabrous; peridial wall composed of thick-walled cells of textura angularis. Asci subcylindrical to clavate, unitunicate, apex flat to rarely rounded, (63–)67.5–80.5(–89) × (8.5–)9–12(–14.5) μm (av. 74 × 4 μm, n = 142). Ascospores obliquely uniseriate or irregularly biseriate at apex of the asci, broadly ellipsoidal to ellipsoidal, 1-septate, (10–)11–13.5(–15) × 4.5–5.5(–6) μm (av. 12.2 × 5.3 μm, n = 202), pale yellow-brown to golden yellow, thick-walled, longitudinally finely striated, often constricted at septum.

Conidiophores erect or prostate from substrate and abundant on aerial mycelium straight or flexuous, smooth- and thin-walled, simple or branched several times irregularly or sympodially, bearing terminal and lateral, single monophialides; phialides subulate to subcylindrical, (16–)17.5–43.5(–67.5) × (2–)3–5 μm (av. 31.5 × 3.6 μm, n = 126), smooth- and thin-walled, conidiogenous loci with rather conspicuous periclinal thickening and a short, flared collarette; aerial conidia of two types: microconidia ellipsoidal, clavate to subcylindrical, straight or more often gently curved, 0–1(–2)-septate, hyaline, smooth- and thin-walled, (5.5–)9–16.9(–23.5) × (2.5–)3.5–5(–6) μm (av. 13.1 × 4 μm, n = 142), clustering in false heads at tip of monophialides; macroconidia falcate and multiseptate, gently dorsiventrally curved, base flattened, inconspicuously or distinctly notched, when notched almost indistinguishable in shape from sporodochial conidia, (1–)3–6-septate, smooth- and thick-walled; 1-septate conidia: (16.5–)19–23(–24.5) × 4–4.5 μm (av. 21.7 × 4.3 μm, n = 14); 2-septate conidia: (23–)24–28.5(–29.5) × 4.5–6 μm (av. 25.8 × 5.2 μm, n = 8); 3-septate conidia: (24.5–)28.5–40(–41.5) × 4–5.5(–6) μm (av. 34 × 4.7 μm, n = 50); 4-septate conidia: (39.5–)45–57.5 × 4.5–5.5(–6) μm (av. 51.3 × 5.1 μm, n = 60); 5-septate conidia: (59–)60–75.5(–80) × 5–6(–6.5) μm (av. 67.6 × 5.6 μm, n = 80); 6-septate conidia: (69.5–)70–77.5(–79) × (4.5–)5–5.5(–6) μm (av. 73.6 × 5.3 μm, n = 50); overall: (16.5–)36.5–73(–80) × (4–)4.5–6(–6.5) μm (av. 54.9 × 5.2 μm, n = 262). Sporodochia cream, pale green to olive-green. Sporodochial conidiophores sparingly branched, verticillately or irregularly; sporodochial phialides subcylindrical, subulate to somewhat doliiform, often slightly swollen near base, (13.5–)15–20(–22.5) × (3.5–)4–5.5 μm (av. 17.6 × 4.6 μm, n = 96), smooth- and thin-walled, conidiogenous loci with inconspicuous periclinal thickening and a short, non-flared collarette. Sporodochial conidia moderately dorsiventrally curved with nearly parallel lines, narrowing gently toward base; apical cell often about equal length than adjacent cell, blunt to somewhat conical with curved apex; basal cell barely to distinctly notched, (2–)5–8(–9)-septate, hyaline, smooth- and thick-walled; 2-septate conidia: 28 × 4.5 μm (n = 2); 3-septate conidia: 49.5 × 5.5 μm (n = 2); 4-septate conidia: 43.5–50.5(–51.5) × 4.5–5.5 μm (av. 47.1 × 5.1 μm, n = 12); 5-septate conidia: (51.5–)56.5–77.5(–82.5) × (4.5–)5–6(–6.5) μm (av. 67 × 5.5 μm, n = 44); 6-septate conidia: (74–)76–86(–87.5) × (5.5–)6–7(–7.5) μm (av. 81.1 × 6.3 μm, n = 40); 7-septate conidia: (77–)81–90(–95.5) × (5.5–)6–7 μm (av. 85.5 × 6.3 μm, n = 128); 8-septate conidia: (80.5–)84.5–92.5(–94) × (5.5–)6–7 μm (av. 88.6 × 6.4 μm, n = 48); 9-septate conidia: 90.5 × 7 μm (n = 2); overall: (28–)66–93.5(–95.5) × (4.5–)5.5–7(–7.5) μm (av. 79.6 × 6.1 μm, n = 278). Chlamydospores abundant, globose to subglobose, smooth- or rough- and thick-walled, 5.5–10 μm diam, terminal or intercalary in hyphae or conidia, solitary or in chains.

Colonies on PDA growing in dark with an average radial growth rate of 1.3–3.3 mm/d at 24 °C, reaching 20–46 mm diam in 7 d at 24 °C; white, pale luteous, saffron to sienna, flat, regular or irregular in shape, velvety to felty, with or without concentric rings of aerial mycelium; margin entire. Reverse white to pale straw. On OA incubated in dark reaching 66–78 mm diam in 7 d at 24 °C; white, cream to buff, flat, at first membranous turning velvety to floccose; margin entire. Reverse white, cream to brick or umber.

Additional materials examined. Netherlands, Ouderkerk aan de Amstel, glasshouse, from Rosa sp. dead parts, May 1997, H.A. v. Kesteren, CBS 833.97; unknown location, from Capsicum annuum, 25 May 1987, J.W. Veenbaas-Rijks, CBS 353.87 = NRRL 22657 = PD 87/236; from stem spot in Gerbera sp. besides Rhizoctonia solani, unknown date and collector, CBS 354.87 = NRRL 22238 = PD 87/238. – Panama, Panama Canal Zone, Fort Sherman, from unsterilized dewaxed cotton duck, 4 Aug. 1945, A.S. Barghoorn, CBS 225.58 = NRRL 22235 = BBA 64431 = QM 679. – Unknown, unknown substrate and date, C.D. Sherbakoff (BPI 453044).

Notes — This homothallic species, also known as phylogenetic species FSSC 21, produces abundant perithecia on diverse artificial media, irrespective of culture conditions. As frequently found with old species descriptions, the protologue of this species does not differentiate between aerial or sporodochial macroconidia. The original description measurements are close to those observed for the aerial macroconidia here. These include mostly 3–4-septate (predominantly 4-septate) conidia with an average size of 34 × 4.7 μm (34.7 × 4.6 μm in the protologue) for the 3-septate conidia.

Neocosmopora ipomoeae (as Hyp. ipomoeae) was historically connected to the asexual morph F. javanicum. However, F. javanicum was later thought to be not conspecific with N. ipomoeae on the basis of its pathogenicity to cucumbers (Nirenberg & Brielmaier-Liebetanz 1996). The same authors connected Hyp. ipomoeae to the asexual morph F. striatum, based on pathogenicity and morphological features. In this study, the morphology of the asexual morph of N. ipomoeae disagrees with the original concept of F. striatum. A photograph deposited by C.D. Sherbakoff illustrating conidia of F. striatum, is available at BPI (BPI 453044) although without a clear indication of the specimen’s original host. The structures depicted (sporodochial conidia and what seems to be a single microconidium) are largely reminiscent of Wollenweber’s illustration of authentic material of F. striatum (Wollenweber 1916, No 406; Fig. 20) though they deviate in size, shape and morphology of the apical and basal cell compared to the modern concepts of either F. javanicum or F. striatum (Gerlach & Nirenberg 1982, Nirenberg & Brielmaier-Liebetanz 1996), showing shorter and fewer-septate conidia. Therefore, the doubtful synonymy of F. striatum under H. ipomoeae is retained here.

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Fig. 20.

Fusarium striatum. a. Drawing of an authentic specimen by Wollenweber (1916); b. photograph by C.D. Sherbakoff depicting conidia (BPI 453044).

No authentic living biological material appears to exist for either F. javanicum or F. striatum. Three specimens identified as F. javanicum by C.D. Sherbakoff, W.H. Wollenweber and O.A. Reinking were retrieved from BPI (BPI 452275–452278) and DNA extraction was attempted. These specimens proved to be an assembly of different taxa. Specimen BPI 452275 (ATCC 22403), a dried culture on PDA from an undetermined substrate, exhibits discordant morphological features, while rDNA and tef1 sequences relate this fungus with Fusarium poae, hence not Neocosmospora (data not shown). Only tef1 sequences were obtained for BPI 452278, collected from dead fruits of Theobroma cacao in Cameroon. This single locus indicated that this fungus clusters within N. solani s.str., which agrees to some degree with its micromorphology. The third specimen, BPI 452276, from an undetermined substrate, although not in good condition, could represent F. javanicum, although it is morphologically different to the asexual morph of N. ipomoeae, having much shorter 2–5-septate conidia. However, genomic DNA extraction was not attempted from this specimen.

Neocosmospora keleraja Samuels et al., Mycologia 103: 1326. 2011

Synonym. Fusarium kelerajum Samuels et al., Mycologia 103: 1326. 2011.

Typus. Sri Lanka, North Central Province, Minneriya National Forest, c. 2 km from forest headquarters, mixed evergreen dry forest, on trunk of Yakuda marang, fallen but still alive, 14 Dec. 2002, G.J. Samuels, A. Nalim, N. Dayawansa & R. Wiejesendera (holotype BPI 871413, culture ex-type FRC S-1839 = G.J.S. 02-122).

Description & Illustration — Nalim et al. (2011).

Additional materials examined. Sri Lanka, North Central Province, vic. Giritale, Giritale Forest Training Centre, in low mixed evergreen forest, semi-arid, on small branch of standing dead small tree, 13 Dec. 2002, G.J. Samuels, A. Nalim, N. Dayawansa, K. Poldmaa, CBS 125720 = FRC S-1837 = G.J.S. 02-114 (culture ex-paratype), CBS 125722 = FRC S-1836 = G.J.S. 02-113 (culture ex-paratype).

Notes — Neocosmospora keleraja is similar to N. mahasenii but can be distinguished by shorter 4-septate conidia and longer ascospores. The former species is also characterised by tall aerial conidiophores, often coronated by a branched apical penicillus of long phialides (Nalim et al. 2011). This species is also similar to N. acutispora and N. robusta. However, N. keleraja can be distinguished by the frequent septation of its sporodochial conidia (up to 9-septate vs up to 7-septate in N. acustispora and N. robusta), which are somewhat wider, with relatively short and hooked apical cells, than the longer and tapered apical cells of N. acutispora and the blunt apical cells of N. robusta. The last two species also differ from N. keleraja in their biogeography and host associations: N. acutispora is known from Coffea arabica in Guatemala and N. robusta from bark in Venezuela.

Neocosmospora keratoplastica (Geiser et al.) Sand.-Den. & Crous, Persoonia 41: 120. 2017 (2018)

Basionym. Fusarium keratoplasticum Geiser et al., Fungal Genet. Biol. 53: 68. 2013.

Synonyms. (Cephalosporium keratoplasticum T. Morik., Mycopathologia 2: 66. 1939 (Nom. inval., Art. 39.1)).

(Hyalopus keratoplasticum T. Morik. ex M.A.J. Barbosa, Subsidios Para o Estudo Parasitologico do Genero Hyalopus Corda, 1838: 19. 1941 (Nom. inval., Art. 39.1)).

Typus. USA, Virginia, Winchester, from indoor plumbing, June 2009, unknown collector (holotype FRC S-2477, culture ex-type FRC S-2477).

Descriptions & Illustrations — Short et al. (2013), Sandoval-Denis & Crous (2018).

Additional materials examined. Belgium, Heverlee, greenhouse humic soil, B.G. Desai, CBS 144389 = MUCL 18301. – Japan, Nagao Institute, from human eye, Harada, CBS 490.63 = NRRL 22661 (culture ex-type of C. keratoplasticum).

Notes — Neocosmospora keratoplastica is one of the most important human pathogenic species in the genus. It is often associated with human corneal infections, but also known to infect other superficial locations and to cause deep-seated infections. This species is also known to attack various animal hosts, particularly in aquatic environments (O’Donnell et al. 2008, 2016, Short et al. 2013, Sarmiento-Ramírez et al. 2014, 2017, Fernando et al. 2015).

Known as phylogenetic species FSSC 2, this taxon was recently recombined in Neocosmospora with an erroneous type citation for the basionym (Sandoval-Denis & Crous 2018), which is corrected here.

Morphologically, N. keratoplastica is distinguishable from other clinically relevant species by the production of small-sized sporodochial conidia, overlapping in conidial size and septation with the non-human-pathogenic species N. brevis, N. diminuta and the unnamed phylogenetic species FSSC 12. However, N. keratoplatica can be distinguished from N. brevis and N. diminuta based on the falcate multiseptate conidia formed on the aerial conidiophores only, whereas N. keratoplastica produces true sporodochia and sporodochial conidia. Neocosmospora keratoplastica can be distinguished from FSSC 12 based on the production of more cylindrical sporodochial conidia, with rounded apical cells and barely notched foot cells, contrasting with the more wedge-shaped sporodochial conidia of FSSC 12 that have more or less pyramidal apical cells and commonly protruding foot cells (Sandoval-Denis & Crous 2018).

Neocosmospora kuroshio F. Na et al. ex Sand.-Den. & Crous, sp. nov. — MycoBank MB831184

Synonym. (Fusarium kuroshium F. Na et al., Plant Disease 102: 1159. 2018 (Nom. inval., Art. 40.7)).

Etymology. Derived from the common name of the ambrosia beetle vector, Kuroshio Shot Hole Borer (from Na et al. 2018).

Typus. USA, California, San Diego County, El Cajon, surface of Euwallacea sp. galleries in infested Platanus racemosa, 14 Dec. 2013, A. Eskalen (holotype BPI 910340 designated here, culture ex-type CBS 142642, isotype UCR 3641).

Description & Illustration — Na et al. (2018).

Notes — Fusarium kuroshium was invalidly published as the causal agent responsible for dieback of numerous tree species (Na et al. 2018). The name was invalid since two specimens on two different collections were cited as holotype (Art. 40.7). The phylogenetic boundaries of the clade representing N. kuroshio (as phylogenetic species AF-12) have been well-studied and delimited (O’Donnell et al. 2015, 2016); while morphological and ecological information attributed to this taxon clearly indicate that it is a true species. Therefore, the name is validated here based on the original published data and its ex-type culture CBS 142642 (Na et al. 2018) as a new species in Neocosmospora.

Neocosmospora kurunegalensis Samuels et al., Mycologia 103: 1324. 2011

Synonym. Fusarium kurunegalense Samuels et al., Mycologia 103: 1323. 2011.

Typus. Sri Lanka, Wagamba Province, Kurunegala. private garden, on recently cut tree, 12 Dec. 2002, G.J. Samuels, A. Nalim, K. Poldmaa (holotype BPI 871391, culture ex-type CBS 119599 = G.J.S. 02-94).

Description & Illustration — Nalim et al. (2011).

Additional material examined. Germany, Göttingen, from Phaseolus vulgaris, 30 Aug. 1983, H. Nirenberg, CBS 835.85 = NRRL 22662 = BBA 64384.

Notes — Nalim et al. (2011) indicated that this species is recognisable by the formation of ‘intercalary phialides’ on the aerial conidiophores, recorded as proliferating conidiophores on which a new axis develops just below the previous conidiogenous locus. Thus, giving the appearance of intercalary phialides, contrasting with the more common type of proliferating conidiophores on which a new axis develops through the previous conidiogenous opening. This seems to be a rather uncommon feature, also observed here, on the closely related species N. cryptoseptata, N. nirenbergiana, and more rarely in N. samuelsii. These species all belong to Clade 2 of Neocosmospora (O’Donnell 2000). An exception to this clade is N. diminuta, a member of Clade 3, for which this proliferating pattern was also observed.

Typification details on the original publication cite BPI 872931 as holotype, which is incorrect. The correct holotype specimen is BPI 871391 (as stated in BPI: ‘typographic error in protologue cites BPI 872931’). Strain CBS 835.85 is tentatively included in N. kurunegalensis based on phylogenetic data, although with a markedly different host and geographic origin.

Neocosmospora lichenicola (C. Massal.) Sand.-Den. & Crous, Persoonia 41: 120. 2017 (2018) — Fig. 21

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Fig. 21.

Neocosmospora lichenicola (ex-epitype culture CBS 623.92). a–c. conidiophores; d. microcyclic conidiogenesis; e–g. conidia. — Scale bars = 10 μm.

Basionym. Fusarium lichenicola C. Massal., Ann. Mycol. 1: 223. 1903.

Synonyms. Bactridium lichenicolum (C. Massal.) Wollenw., Fusaria Autographice Delineata 1: 456. 1916.

Cylindrocarpon lichenicola (C. Massal.) D. Hawksw., Bull. Brit. Mus. (Nat. Hist.), Bot. 6: 273. 1979.

Monacrosporium tedeschii A. Agostini, Atti Ist. Bot. Lab. Crittog. Univ. Pavia 4: 195. 1933.

Euricoa dominguiesii Bat. & H. Maia, Anais Soc. Biol. Pernambuco 13: 152. 1955.

Hyaloflorea ramosa Bat. & H. Maia, Anais Soc. Biol. Pernambuco 13: 155. 1955.

Neocosmospora ramosa (Bat. & H. Maia) L. Lombard & Crous, Stud. Mycol. 80: 227. 2015.

Mastigosporium heterosporum R.H. Petersen, Mycologia 51: 729. 1959.

Typus. Italy, Verona, Tregnago, on Polycauliona candelaria (as Candelaria concolor), Nov. 1902, C. Massalongo (holotype PAD). – Germany, Göttingen, necrotic wounds of patient under chemotherapy, unknown date, Staatliches Medizinaluntersuchungsamt Göttingen (epitype of Fusarium lichenicola CBS H-23983 designated here, MBT387219, culture ex-epitype CBS 623.92).

Descriptions & Illustrations — Wollenweber (1916), Petersen (1959), Hawksworth (1979), Summerbell & Schroers (2002).

Additional materials examined. Brazil, Bahía, from air, 2 Feb. 1955, E.A.F. da Matta, CBS 522.63 = MUCL 8049 = IMUR 320 (culture ex-type of E. dominguesii); Pernambuco, Recife, Dois Irmãos, Universidade Rural, from soil, 16 Mar. 1961, unknown collector, CBS 166.67 = IMUR 1797 (culture ex-type of M. pernambucensis); Salvador, from air, 2 Apr. 1955, E.A.F. de Matta, CBS 509.63 = MUCL 8050 = IMUR 410 (culture ex-type of H. ramosa). – Japan, from human eye, unknown date and collector, CBS 483.96 = IFO 30561 = NBRC 30561. – Somalia, Mogadishu, human scabies-like skin condition, unknown date, A. Agostini, CBS 279.34 (culture ex-type of M. tedeschii). – Tahiti, French Polynesia, soil from damp river bed, unknown date and collector CBS 279.59 = ATCC 13427 (culture ex-type of M. heterosporum).

Notes — Also known as phylogenetic species FSSC 16, this taxon was recently recombined in Neocosmospora, based on F. lichenicola, an infrequent human pathogen. Although reported from superficial and invasive human infections, this fungus is also able to cause disease in a diverse group of plant hosts (Summerbell & Schroers 2002, Sandoval-Denis et al. 2018).

Morphologically, this species is unique in the genus Neocosmospora based on the ellipsoidal to cylindrical, 0–3-septate aerial conidia with the basal cells displaying a short, truncate base instead of the typical foot-shaped cell common among members of this genus. However, a phylogenetic study that included several strains of C. lichenicola indicated that this species belonged to Neocosmospora (as the F. solani species complex; Summerbell & Schroers 2002).

An epitype is designated here to stabilise the species and fix the application of the name to this phylogenetic clade, largely known to represent N. lichenicola. Although CBS 623.92 is not from the same host or country, but from human clinical origin, N. lichenicola is a recognised human pathogenic species. The selected epitype is in excellent morphological condition and represents the morphological concept of the species.

Neocosmospora liriodendri Sand.-Den. & Crous, sp. nov. — MycoBank MB831185; Fig. 22

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Fig. 22.

Neocosmospora liriodendri (ex-type culture CBS 117481). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–f. conidiophores; g–h. chlamydospores; i–j. conidia. — Scale bars = 10 μm.

Etymology. Name refers to the host genus Liriodendron from which this fungus was isolated.

Typus. USA, Maryland, from Liriodendron tulipifera, unknown date and collector (holotype CBS H-23984 designated here, culture ex-type CBS 117481 = NRRL 22389 = BBA 67587 = G.J.S 91-148).

Conidiophores prostrate or erect, abundant on substrate and aerial mycelium, straight, smooth- and thin-walled, simple or sparingly verticillately and laterally branched, bearing terminal, single monophialides; phialides subulate to subcylindrical, (40–)48–66.5(–71.5) × (2.5–)3–4(–5) μm (av. 57.3 × 3.4 μm, n = 48), smooth- and thin-walled, conidiogenous loci with or without inconspicuous periclinal thickening and a short, somewhat flared collarette; conidia obovoidal, subcylindrical to clavate, straight or gently curved 0(–1)-septate, hyaline, smooth- and thin-walled, (4.5–)5.5–11(–16) × (2–)2.5–4(–5) μm (av. 8.2 × 3.2 μm, n = 82), crowding in false heads at tip of monophialides. Sporodochia not observed. Chlamydospores globose to subglobose, smooth-walled, (4.5–)6–10.5 μm diam; terminal or intercalary, solitary or in short chains.

Colonies on PDA growing in dark with an average radial growth rate of 2.9–3.2 mm/d at 24 °C, reaching 40–45 mm diam in 7 d at 24 °C; white, straw to primrose; with thick, white radial patches of dense, white aerial mycelium; flat to slightly raised, velvety to cottony; margin entire. Reverse straw, buff to honey. On OA incubated in dark reaching 37–43 mm diam in 7 d at 24 °C; white, flat, velvety to granular with inconspicuous concentric rings of aerial mycelium; margin entire. Reverse straw to buff.

Notes — Neocosmospora liriodendri is a well-defined phylogenetic species, previously known as FSSC 24 (O’Donnell et al. 2008). It is only known from a single haplotype. Morphologically, it resembles N. parceramosa, both species producing much similar conidia formed only from relatively long phialides on simple aerial conidiophores, and showing comparable macroscopic features. Nevertheless, N. liriodendri differs by commonly forming sparingly branched conidiophores, a reduced growth rate on artificial media (2.9–3.2 vs 3.2–3.5 mm/d in N. parceramosa), and larger, smooth chlamydospores (up to 10.5 vs up to 8.5 μm diam, smooth to tuberculate in N. parceramosa).

Neocosmospora longissima Sand.-Den. & Crous, sp. nov. — MycoBank MB831186; Fig. 23

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Fig. 23.

Neocosmospora longissima (ex-type culture CBS 126407). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–e. sporodochia formed on the surface of carnation leaves; f. chlamydospore; g–j. aerial conidiophores; k–l. aerial conidia; m–o. sporodochial conidiophores and phialides; p–q. sporodochial conidia. — Scale bars: c–e = 100 μm; f = 5 μm; all others = 10 μm.

Etymology. From Latin longissimus meaning ‘longest, very long’; referring to its large sporodochial conidia.

Typus. New Zealand, Russell State Forest, Ngaiotonga Scenic Reserve, from tree bark, unknown date, G.J. Samuels, L.M. Kohn, D. Brown & E. Brown (holotype CBS H-23985 designated here, culture ex-type CBS 126407 = G.J.S. 85-72).

Conidiophores erect or prostrate on substrate, abundant on aerial mycelium, straight, smooth- and thin-walled, simple or commonly irregularly or verticillately branched several times, bearing terminal, single monophialides; phialides subulate to subcylindrical, (32–)37–53.5(–69) × (2–)2.5–3.5(–4) μm (av. 45.2 × 3 μm, n = 82), smooth- and thin-walled, conidiogenous loci with inconspicuous periclinal thickening, collarettes absent; aerial conidia obovate, ellipsoidal or reniform, 0-septate, hyaline, smooth- and thin-walled, (4.5–)5–9(–13) × (2–)2.5–4(–5.5) μm (av. 7.1 × 3.2 μm, n = 108), clustering in false heads at tip of monophialides. Sporodochia at first cream, becoming golden brown and quickly clustering into pionnotes. Sporodochial conidiophores densely verticillately branched; sporodochial phialides subcylindrical, ampulliform to doliiform, (9–)12–16.5(–21) × 3–4.5(–5.5) μm (av. 14.2 × 3.9 μm, n = 112), smooth- and thin-walled, conidiogenous loci lacking periclinal thickening or collarettes. Sporodochial conidia mostly wedge-shaped with marked dorsal curvature, rarely almost straight, tapering toward both ends and abruptly toward apex; apical cell often about equal length or longer than adjacent cell, conical with curved, somewhat elongate and rounded apex; basal cell barely to distinctly notched, straight, (3–)5–8-septate, hyaline, smooth- and thick-walled; 3-septate conidia: (34–)46–86.5(–79) × (4.5–)5–6 μm (av. 66.4 × 5.5 μm, n = 16); 5-septate conidia: (50.5–)56–71(–76) × 5–6(–6.5) μm (av. 63.5 × 5.7 μm, n = 60); 6-septate conidia: (61–)63.5–79.5(–91) × 5–6.5(–7) μm (av. 70 × 5.9 μm, n = 28); 7-septate conidia: (77–)80.5–95.5(–98) × (5–)6–8 μm (av. 88 × 6.9 μm, n = 36); 8-septate conidia: (86.5–)89.5–98.5(–99) × (6–)6.5–8 μm (av. 94.1 × 7.2 μm, n = 48); overall: (34–)61.5–93(–99) × (4.5–)5.5–7.5(–8) μm (av. 77.2 × 6.3 μm, n = 188). Chlamydospores abundant, globose to obpyriform, smooth- and thick-walled, 6.5–8.5(–9) μm diam, terminal, intercalary or lateral in hyphae, solitary or in groups.

Colonies on PDA growing in dark with an average radial growth rate of 6–8 mm/d at 24 °C, filling a 90 mm diam Petri dish in 7 d at 24 °C; sienna, umber to rust, with radial patches of white to cream aerial mycelia, flat, velvety to felty; margin entire. Reverse ochreous to umber. On OA incubated in dark filling a 90 mm diam Petri dish in 7 d at 24 °C; buff with radial patches of short, white aerial mycelium, flat, velvety to granulose; margin entire. Reverse buff.

Notes — Neocosmospora longissima is rather unique in the genus Neocosmospora based on the remarkably long, typically acute and tapered, almost pointy sporodochial conidia produced. Morphologically, the most similar species to N. longissima include N. bataticola and N. macrospora. However, N. longissima is clearly distinct based on conidial shape and other micromorphological and cultural characteristics. Macroscopically, N. longissima exhibits sienna to rust coloured colonies, in contrast to the intense orange or red coloured colonies of N. bataticola. Furthermore, N. longissima lacks aerial macroconidia, which N. bataticola readily produces in culture. Neocosmospora macrospora, in comparison with N. longissima, produces up to 9-septate sporodochial conidia, which are slightly shorter and slenderer (up to 90 μm long and 6.7 μm wide vs up to 99 μm long and 8 μm wide in N. longissima), with inconspicuously tapered ends.

Neocosmospora macrospora Sand.-Den. et al., Persoonia 40: 21. (2017) 2018

Typus. Italy, Sicily, Catania, Guardia, from Citrus sinensis crown, 9 Mar. 2015, V. Guarnaccia (holotype CBS H-23023, culture ex-type CBS 142424 = CPC 28191).

Description & Illustration — Sandoval-Denis et al. (2018).

Additional materials examined. Italy, Sicily, Catania, Guardia, from Citrus sinensis crown, 9 Mar. 2015, V. Guarnaccia, CPC 28192, CPC 28193.

Notes — This species was recently described from Citrus trees in Sicily, Italy, that were showing symptoms of dry root rot. The isolates were not proven to be the etiologic agent of the rot (Sandoval-Denis et al. 2018). The study authors provided a brief discussion on the similarity between N. macrospora and the traditional morphological concepts of F. eumartii and F. ensiforme. However, these discordant species concepts are shown here to be erroneous. Neocosmospora macrospora is morphologically close to N. longissima in terms of conidial size, although the two species are phylogenetically unrelated and morphologically distinct (see notes under N. longissima).

Neocosmospora mahasenii Samuels et al., Mycologia 103: 1325. 2011

Synonym. Fusarium mahasenii Samuels et al., Mycologia 103: 1325. 2011.

Typus. Sri Lanka, North Central Province, vic. Giritale. Giritale Forest Training Center, on small branch of live tree, 13 Dec. 2002, G.J. Samuels, A. Nalim, N. Dayawansa & K. Poldmaa (holotype BPI 871393, culture ex-type CBS 119594 = FRC S-1845 = G.J.S. 02-105).

Description & Illustration — Nalim et al. (2011).

Notes — Neocosmospora mahasenii is known from living and dead wood in Sri Lanka, and it clusters in Clade 2 of Neocosmospora (O’Donnell 2000, Nalim et al. 2011). According to Nalim et al. (2011), N. mahasenii is morphologically similar to N. rectiphora, another species known from dead plant material in South Asia. However, N. rectiphora is phylogenetically distant and clusters in a monotypic lineage, in the paraphyletic Clade 2 (O’Donnell 2000). Neocosmospora mahasenii is distinct from N. rectiphora in the production of a blue pigment in mature sporodochia, slower growth rates on PDA and shorter ascospores (Nalim et al. 2011).

Neocosmospora martii (Appel & Wollenw.) Sand.-Den. & Crous, comb. nov. — MycoBank MB831187; Fig. 24

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Fig. 24.

Neocosmospora martii (lectotype of Fusarium martii BPI 452385). a. Original illustration by Wollenweber (1916); b–c. herbarium specimen; d–f. sporodochia, g. aerial microconidia; h. aerial macroconidia; i. sporodochial conidiophore; j–k. sporodochial conidia. — Scale bars: c = 1 cm; d = 2 mm; e–f = 100 μm; all others = 10 μm.

Basionym. Fusarium martii Appel & Wollenw., Arbeiten Kaiserl. Biol. Anst. Ld.- u. Forstw. 8: 83. 1910.

Synonyms. Fusarium solani var. martii (Appel & Wollenw.) Wollenw., Fusaria Autographice Delineata 3: 1034. 1930.

Neocosmospora croci Guarnaccia et al., Persoonia 40: 17 (2017) 2018.

Typus. Germany, Berlin, on rotten tuber of Solanum tuberosum, Sept. 1909, unknown collector (lectotype of Fusarium martii BPI 452385 here designated, MBT387222); from S. tuberosum cultivar Maritta, unknown date and collector (epitype of F. martii CBS H-23986 designated here, MBT387223; culture ex-epitype CBS 115659 = FRC S-0679 = MRC 2198).

Descriptions & Illustrations — Appel & Wollenweber (1910), Reinking & Wollenweber (1927), Wollenweber (1931, 1935), Sandoval-Denis et al. (2018, as N. croci).

Additional materials examined. Germany, Berlin, dried cultivated isolate from Solanum tuberosum, 1909 (on culture 1909/1910), H.W. Wollenweber, BPI 452384. – Italy, Sicily, Catania, Paternó, Citrus sinensis crown, 9 Mar. 2015, V. Guarnaccia, CBS 142423 = CPC 27186 (culture ex-type of N. croci); Sicily, Catania, Paternó, C. sinensis crown, 9 Mar. 2015, V. Guarnaccia, CPC 27187. – Netherlands, Amsterdam, North Holland, from Pisum sativum stem, 1910, W.C. Scholten (presumptive collector), BPI 452383; unknown location, from S. tuberosum, 8 Mar. 1911, J. Westerdijk (presumptive collector), BPI 452379. – USA, Nebraska, Buffalo County, Kearney landfill, soil, unknown date and collector, CBS 127135 = RMF 7653.

Notes — Material of Fusarium martii as well as later collections of the same fungus from different hosts were received from BPI, all authenticated by H.W. Wollenweber. Significant uncertainty exists regarding the nomenclatural status of the original material from that author, who often proposed new taxa without designating type collections (Stevenson 1971). Although unambiguously linked to the original publication, the specimens treated here are considered as authentic material rather than as types. To stabilize the use of the name, a lectotype is selected here for F. martii, while an epitype is also designated in order to assure access to DNA data for future studies. The selected lectotype (BPI 452385) undoubtedly represents original material for the species, matching with the specimen illustrated as specimen originale in ‘Fusaria Autographice Delineata No 413’, reproduced in Fig. 24. All BPI specimens examined were in excellent condition; micro-morphological characteristics are clearly recognisable and match the original concept of the species as well as the morphological characteristics of modern isolates included in this clade. Moreover, ITS, LSU and tef1 DNA barcodes were obtained for four specimens (BPI 452379, 452383–452385) and analyses of these barcodes demonstrated that these collections all belong to the same taxon.

Neocosmospora croci, a species recently described from Citrus in Sicily, Italy (Sandoval-Denis et al. 2018) is here reduced to synonymy under N. martii. The morphological and ecological characteristic of N. croci match with those reported for F. martii (Appel & Wollenweber 1910, Sherbakoff 1915, Wollenweber 1931); however, the uncertain application of the latter taxon’s name prevented the two species from being properly compared.

Fusarium martii was originally described as having a blue colouration (Appel & Wollenweber 1910, Sherbakoff 1915), which was not observed here on synthetic media. However, a feature quite evident from the original specimens of F. martii is the red pigmentation of the fungal material. This character also matched with our morphological observations and with the characteristics described for N. croci (Sandoval-Denis et al. 2018).

Neocosmospora metavorans (Al-Hatmi et al.) Sand.-Den. & Crous, Persoonia 41: 121. 2018

Basionym. Fusarium metavorans Al-Hatmi et al., Med. Mycol. 56: S147. 2018.

Typus. Greece, Athens, from human pleural effusion, 2013, M. Drogari (holotype CBS 135789, maintained as metabolically inactive culture, culture ex-type CBS 135789).

Descriptions & Illustrations — Al-Hatmi et al. (2018), Sandoval-Denis et al. (2018).

Additional materials examined. Italy, from Malus sylvestris, unknown date and collector, CBS 233.36 = NRRL 22654. – Spain, Reus, human foot, unknown date, F. Ballester, CBS 143219 = NRRL 46708 = FMR 8634; unknown location, human corneal ulcer, unknown date and collector, CBS 143194 = IMI 226114 = NRRL 22782. – Turkey, from human, unknown date and collector, CBS 143215 = NRRL 37640 = UTHSC R-3564. – USA, Illinois, from human, unknown date, P. Kammeyer, CBS 143218 = NRRL 46237; Maryland, from human eye, unknown date and collector, CBS 130400 = NRRL 43489 = CDC 2006743456; human toenail cancer, unknown date and collector, CBS 143210 = NRRL 32785 = FRC S-1123; Michigan, from human, unknown date, M. Brandt, CBS 143216 = NRRL 43717; New England, from human bone, unknown date, A. Fothergill, CBS 143202 = NRRL 28542 = UTHSC 98-1246; San Francisco, human eye, unknown date and collector, CBS 143195 = NRRL 22792 = IMI 153617; Texas, human eye, unknown date and collector, CBS 143213 = NRRL 32849 = FRC S-1355 = UTHSC 95-2552; human foot, unknown date and collector, NRRL 28553 = UTHSC 97-2574; unknown location, from human, unknown date and collector, CBS 143198 = NRRL 28016 = CDC B-5779; CBS 143199 = NRRL 28017 = CDC B-5780; CBS 143200 = NRRL 28018 = CDC B-5781; CBS 143201 = NRRL 28019 = CDC B-5782.

Notes — Neocosmospora metavorans is a species mostly known from human clinical samples, but can also be found on other animals and less frequently on plant hosts (O’Donnell et al. 2008, Al-Hatmi et al. 2018, Sandoval-Denis & Crous 2018). Previously known as phylogenetic species FSSC 6, N. metavorans is one of the most relevant species in medical mycology, associated with infections ranging from being superficial to disseminated (O’Donnell et al. 2008). The clade representing N. metavorans displays significant genetic variation, with a complex internal phylogenetic structure, supported by significant evidence of sexual recombination (Φw = 0.001, Fig. 2).

Among the clinically relevant species of Neocosmospora, N. metavorans is morphologically reminiscent of N. solani and N. suttoniana, but distinct based on the wider sporodochial conidia with conspicuous foot cells (Sandoval-Denis & Crous 2018). Sporodochial conidia of N. metavorans are similar in size and septation to those of N. petroliphila and N. tonkinensis. However, the former taxon can be distinguished by its conidial shape, with blunt, short apical cells and protuberant foot-cells, vs the elongated apical cells and barely notched foot cells of N. petroliphila, and by short ellipsoidal aerial conidia, vs the elongate clavate to ellipsoidal, multiseptate aerial conidia of N. tonkinensis.

Neocosmospora mori Sand.-Den. & Crous, sp. nov. — MycoBank MB831188; Fig. 25

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Fig. 25.

Neocosmospora mori (ex-type culture CBS 145467). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–f. sporodochia formed on the surface of carnation leaves; g–h. chlamydospores; i–l. aerial conidiophores; m–n. aerial conidia; o–q. sporodochial conidiophores and phialides; r–s. sporodochial conidiophores. — Scale bars: c–f = 100 μm; g–h = 5 μm; i–k = 20 μm; all others = 10 μm.

Synonyms. (Fusarium solani f. mori Sawada, Special Publication College of Agriculture, National Taiwan University 8: 222. 1959 (Nom. inval., Art. 39.1)).

(Hypomyces solani f. mori Y. Sakurai & Matuo, Ann. Phytophathol. Soc. Japan 24: 222. 1959 (Nom. inval., Art. 39.1)).

(Fusarium solani f. mori Y. Sakurai & Matuo, Ann. Phytopathol. Soc. Japan 24: 222. 1959 (Nom. inval., Art. 39.1)).

Etymology. Name refers to the host genus Morus from which this fungus was isolated.

Typus. Japan, Miyazaki, from Morus alba twig, unknown date and collector (holotype CBS H-23987 designated here, culture ex-type CBS 145467 = NRRL 22230 = MAFF 238539 = ATCC 44934).

Conidiophores erect on substrate mycelium or produced laterally on aerial hyphae, straight, smooth- and thin-walled, commonly unbranched or sparingly irregularly or dichotomously branched, bearing terminal, single monophialides; phialides subulate to acicular, (33–)38–54.5(–65) × 2–3.5 μm (av. 46.4 × 2.7 μm, n = 74), smooth- and thin-walled, conidiogenous loci with rather conspicuous periclinal thickening and a short, non-flared collarette; aerial conidia obovoidal, ellipsoidal to clavate, straight or more often slightly curved, 0(–1–2)-septate, hyaline, smooth- and thin-walled, (5–)6.5–15(–24) × (2–)3–4.5(–6) μm (av. 10.6 × 3.7 μm, n = 117), clustering in false heads at tip of monophialides. Sporodochia cream, pale ochreous to pale olivaceous. Sporodochial conidiophores densely branched, dichotomously, verticillately or irregularly and tightly packed, bearing terminal solitary monophialides or whorls of 2–3 phialides; sporodochial phialides subulate to subcylindrical, (13–)15–21.5(–25) × (3–)4–4.5(–5.5) μm (av. 18.4 × 4 μm, n = 49), smooth- and thin-walled, with inconspicuous periclinal thickening and a short, non-flared collarette. Sporodochial conidia straight or moderately curved at basal and apical cells, widest just above the mid portion and distinctly tapering toward base; apical cell of equal length or slightly longer than adjacent cell, blunt to slightly hooked with rounded apex; basal cell distinctly notched and somewhat bulging, (2–)3–7(–8)-septate, hyaline, smooth- and thick-walled; 2-septate conidia: 26–33 × 4–4.5 μm (n = 2); 3-septate conidia: (28–)34–47(–51) × (3.5–)4–5.5 μm (av. 40.5 × 4.6 μm, n = 28); 4-septate conidia: (37–)40–51.5(–55) × 4–5.5 μm (av. 45.8 × 4.7 μm, n = 20); 5-septate conidia: (43–)50.5–60.5(–65.5) × (4–)5–5.5 μm (av. 55.6 × 5 μm, n = 146); 6-septate conidia: (67–)68.5–76(–79) × 5–6(–6.5) μm (av. 72.2 × 5.5 μm, n = 44); 7-septate conidia (66.5–)72–81(–82.5) × (4.5–)5–6 μm (av. 76.6 × 5.5 μm, n = 9); 8-septate conidia: 91.5 × 6 μm (n = 1); overall: (26–)45–69.5(–91.5) × (3.5–)4.5–5.5(–6.5) μm (av. 57.3 × 5 μm, n = 250). Chlamydospores abundant, globose to subglobose, smooth-walled to verruculose, thick-walled, 6–7(–8) μm diam, terminal or intercalary in hyphae or conidia, solitary or in chains.

Colonies on PDA growing in dark with an average radial growth rate of 4.3–5 mm/d at 24 °C, reaching 60–65 mm diam in 7 d at 24 °C; white to pale luteous, flat, velvety to felty, with concentric rings of short buff to rosy buff aerial mycelium; margin entire. Reverse pale orange to rosy buff. On OA incubated in dark reaching 40–50 mm diam in 7 d at 24 °C; white, becoming ochreous after the formation of numerous sporodochia, flat, velvety to floccose; margin entire. Reverse pale luteous, pale saffron at centre.

Additional material examined. Japan, Nagano, from Morus alba twig, c. 1956, unknown collector, CBS 145468 = NRRL 22157 = MAFF 238538.

Notes — This clade encompasses strains previously assigned to F. solani f. sp. mori, also known as Nec. haematococca MPIII and phylogenetic species FSSC 17. Members of this clade are known to induce stem blight on mulberry (Morus alba) trees (Sawada 1959, Sakurai & Matuo 1959, Matuo & Snyder 1973). Additional sequences from South Korea (M. alba, JS-169), were also included in this study, originating from the whole genome sequence of a non-pathogenic endophytic strain published in Kim et al. (2017; Table 1).

Neocosmospora mori produces sporodochial conidia intermediate in size to those of N. cucurbitae and N. samuelsii. However, the sporodochial conidia of N. mori are typically almost straight with notably tapered ends, while only microconidia are produced from aerial conidiophores. In contrast, the sporodochial conidia in N. cucurbitae are somewhat more cylindrical and curved. Neocosmospora cucurbitae also produces additional cylindrical, multiseptate aerial macroconidia. Neocosmospora samuelsii has thick-walled, robust and relatively strongly curved sporodochial conidia, with elongated and hooked apical cells, and it lacks microconidia, forming instead only typical flat-based and pointy aerial macroconidia.

Neocosmospora nirenbergiana Sand.-Den. & Crous, sp. nov. — MycoBank MB831189; Fig. 26

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Fig. 26.

Neocosmospora nirenbergiana (ex-type culture CBS 145469). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c. sporodochium formed on the surface of carnation leave; d–i. aerial conidiophores; j. aerial conidia; k–m. sporodochial conidiophores and phialides; n–o. sporodochial conidia. — Scale bars: c = 100 μm; d–i = 20 μm; m = 5 μm; all others = 10 μm.

Etymology. In honour of Dr Helgard Nirenberg, for her significant contributions to the taxonomy of Fusarium and related genera.

Typus. French Guiana, on bark of unidentified tree, unknown date and collector (holotype CBS H-23988 designated here, culture ex-type CBS 145469 = NRRL 22387 = BBA 65023 = G.J.S. 87-127).

Conidiophores abundant on substrate mycelium, erect and prostrate, and laterally borne on aerial mycelium, straight, smooth- and thin-walled, often simple or sparingly dichotomously branched, irregular or sympodial, often proliferating through conidiogenous opening, or laterally just below previous conidiogenous locus; bearing terminal and lateral, single monophialides; phialides subulate to subcylindrical, (43–)46–56.5(–61) × 3.5–5 μm (av. 51.1 × 4.2 μm, n = 64), smooth- and thin-walled, with rather inconspicuous periclinal thickening and collarettes; aerial conidia falcate and multiseptate, often with an almost straight ventral line, indistinctly notched to papillate, 4–5-septate, smooth- and thick-walled; 4-septate conidia: (37.5–)40–49(–52) × (6.5–)7–7.5 μm (av. 44.6 × 7.2 μm, n = 28); 5-septate conidia: (42.5–)46.5–54.5(–59.5) × (6.5–)7–8(–8.5) μm (av. 50.5 × 7.3 μm, n = 124); overall: (37.5–)45–54(–59.5) × (6.5–)7–8(–8.5) μm (av. 49.4 × 7.3 μm, n = 152). Sporodochia cream, pale luteous, pale sienna to pale citrine. Sporodochial conidiophores sparingly branched, verticillately or irregularly; sporodochial phialides subcylindrical, subulate to somewhat doliiform, (9–)10.5–15(–18) × (3–)3.5–5(–5.5) μm (av. 12.7 × 4.3 μm, n = 74), smooth- and thin-walled, periclinal thickening at conidiogenous loci inconspicuous or visible, collarettes often wide and somewhat flared. Sporodochial conidia falcate, rarely straight, curvature often more pronounced toward basal end, narrowing toward base; apical cell of equal length to adjacent cell, blunt to somewhat conical with curved and rounded apex; basal cell indistinctly to moderately notched, (2–)5(–6)-septate, hyaline, smooth- and thick-walled; 2-septate conidia: 51–52.5 × 6–6.5 μm (n = 2); 5-septate conidia: (49.5–)53.5–62.5(–73.5) × (5.5–)6–7(–7.5) μm (av. 58 × 6.6 μm, n = 134); 6-septate conidia: 60 × 7 (n = 1); overall: (49.5–)53.5–62.5(–73.5) × (5.5–)6–7(–7.5) μm (av. 57.9 × 6.6 μm, n = 137). Chlamydospores not observed.

Colonies on PDA growing in dark with an average radial growth rate of 3.5–4.1 mm/d at 24 °C, reaching 54–60 mm diam in 7 d at 24 °C; straw, sulphur yellow to pale luteous, flat, velvety to felty, with concentric rings and radial patches of dense and short aerial mycelium; margin entire and filiform with abundant submerged mycelium. Reverse pale luteous, luteous to pale orange at centre. On OA incubated in dark reaching 46–52 mm diam in 7 d at 24 °C; straw, sulphur yellow to pale luteous, becoming scarlet, red to rust at the periphery, flat, velvety to felty, aerial mycelium dense and short arranged in concentric rings and radial patches; margin entire. Reverse pale luteous at centre, with abundant production of a scarlet to red diffusible pigment.

Notes — Neocosmospora nirenbergiana has long been recognised as a distinct species by means of RAPD and ITS-RFLP patterns (Hering 1997), and phylogenies based on the rDNA (Schütt 2001) and rDNA plus tef1 sequences (O’Donnell 2000, Nalim et al. 2011) but has heretofore not formally named. This species clusters within Clade 2 of Neocosmospora and is similar to most members of this clade based on the absence of aerial microconidia. Instead, several members of this clade are characterised by the formation of relatively short and robust aerial conidiophores from which only falcate, multiseptate conidia are produced. In addition, aerial conidiophores tend to proliferate laterally from below the previous conidiogenous locus, a feature also observed for the closest phylogenetic relatives N. cryptoseptata, N. kurunegalensis and N. samuelsii, but not seen for the remaining species known in Clade 2. Neocosmospora nirenbergiana is easily distinguished from N. samuelsii and N. kurunegalense by the production of much shorter sporodochial conidia which are similar in size to those of N. cryptoseptata. However, the sporodochial conidia of N. nirenbergiana are slender, with somewhat longer and hooked apical cells. In addition, N. nirenbergiana produces a scarlet pigment on OA, but not on PDA.

This lineage is only known from the ex-type culture (CBS 145469), which has been recorded to form a sexual morph (O’Donnell 2000, and personal notes from G.J. Samuels). We were, however, unable to induce the sexual morph in this study.

Neocosmospora noneumartii Sand.-Den. & Crous, sp. nov. — MycoBank MB831190; Fig. 27

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Fig. 27.

Neocosmospora noneumartii (ex-type culture CBS 115658). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–e. sporodochia formed on the surface of carnation leaves; f–g. chlamydospores; h–k. aerial conidiophores; l–n. aerial microconidia and macroconidia; o–p. sporodochial conidiophores and phialides; q. sporodochial conidia. — Scale bars: c = 100 μm; d–e = 50 μm; all others = 10 μm.

Etymology. Named after the species similarity with the modern morphological and ecological concept of Fusarium eumartii, but being phylogenetically and morphologically distinct.

Typus. Israel, Palestine, from Solanum tuberosum, unknown date and collector (holotype CBS H-23989 designated here, culture ex-type CBS 115658 = FRC S-0661).

Conidiophores abundant on the aerial mycelium or erect and prostrate on vegetative mycelium, smooth- and thin-walled, at first simple, at maturity sparingly irregularly, verticillately or sympodially branched, bearing terminal monophialides; phialides subulate to subcylindrical, (19–)33.5–64.5(–75) × (2–)2.5–4 (–4.5) μm (av. 49.2 × 3.2 μm, n = 134), smooth- and thin-walled, rarely proliferating, conidiogenous loci with inconspicuous periclinal thickening and a short, non-flared collarette; aerial conidia of two types: microconidia ellipsoidal to subcylindrical, straight to slightly curved, 0–1-septate, hyaline, smooth- and thin-walled, (4.5–)9–15.5(–18.5) × (2–)2.5–4(–4.5) μm (av. 12.2 × 3.2 μm, n = 146), grouped in false heads at tip of monophialides; macroconidia short-falcate and multiseptate, slightly dorsiventrally curved or almost straight, basal cell inconspicuously notched, 1–4-septate, smooth- and thin-walled; 1-septate conidia: 13.5–22.5(–24) × (3.5–)4–5(–5.5) μm (av. 17.6 × 4.4 μm, n = 26); 2-septate conidia: (21–)21.5–24(–25) × (4.5–)5–5.5 μm (av. 22.6 × 5 μm, n = 18); 3-septate conidia: (25.5–)31.5–46(–48.5) × (3.5–)4–5(–6) μm (av. 38.8 × 4.4 μm, n = 70); 4-septate conidia: 44.5–46 × 5–5.5 μm (av. 45.3 × 5.4 μm, n = 24); overall: (13.5–)22–45.5(–48.5) × 4–5.5(–6) μm (av. 33.8 × 4.7 μm, n = 138). Sporodochia cream, ochreous, pale green to grey-green. Sporodochial conidiophores unbranched to densely branched, verticillately or irregularly and tightly packed; sporodochial phialides ampulliform, subcylindrical to subulate, (12–)13.5–18.5(–21) × (3–)3.5–5(–5.5) μm (av. 15.8 × 4.2 μm, n = 74), smooth- and thin-walled, conidiogenous loci with inconspicuous periclinal thickening and a short, non-flared collarette. Sporodochial conidia straight or discreetly dorsiventrally curved, slightly wider on the upper third and tapering toward base; apical cell of equal length than adjacent cell, apex blunt to somewhat papillate; basal cell distinctly notched, (1–)3–6-septate, hyaline, smooth- and thick-walled; 1-septate conidia: 24 × 5 (n = 1); 2-septate conidia: 29.5–30 × 4–5 μm (av. 29.9 × 4.4 μm, n = 8); 3-septate conidia: (26.5–)32.5–53.5(–64.5) × (4–)4.5–6 μm (av. 43.2 × 5.1 μm, n = 116); 4-septate conidia: (34.5–)45–65.5(–67.5) × (4–)4.5–6 μm (av. 55.1 × 5.1 μm, n = 72); 5-septate conidia: (51.5–)59–67.5(–73.5) × 5–6(–6.5) μm (av. 63 × 5.5 μm, n = 140); 6-septate conidia: 68.5–69 × 5.5–6 μm (av. 68.7 × 5.6 μm, n = 8); overall: (24–)40.5–66.5(–73.5) × (4–)4.5–6(–6.5) μm (av. 53.7 × 5.3 μm, n = 345). Chlamydospores abundant, subglobose to globose, smooth- and thick-walled, (7.5–)8.5–11.5(–12) μm diam, terminal or intercalary in hyphae or conidia, solitary, in chains or clusters.

Colonies on PDA growing in dark with an average radial growth rate of 4.7–8 mm/d at 24 °C, reaching 86–90 mm diam in 7 d at 24 °C; white, pale luteous, buff, ochreous to olivaceous, often flat with regular shape, membranous, velvety or felty with sparse, often white, aerial mycelium; margin entire. Reverse white to pale straw. On OA incubated in dark covering an entire 90 mm diam Petri dish in 7 d at 24 °C; white, luteous, buff, flat, at first membranous turning velvety to floccose; margin entire. Reverse white, cream to brick or umber.

Notes — Neocosmospora noneumartii was proposed to represent the important potato storage rot pathogen Fusarium eumartii (as Fusarium solani f. sp. eumartii) by means of host pathogenicity and DNA sequence analyses (Romberg & Davis 2007). DNA barcodes derived from that study showed it corresponds to phylogenetic species FSSC 42. The same authors demonstrated that this lineage also encompasses agents of potato wilt and foot rot of tomato (Solanum lycopersicum). However, the modern concept of Fusarium eumartii is largely polyphyletic, while its morphological circumscription has been subjected to multiple interpretations, all of which diverge significantly from the original description (Gerlach & Nirenberg 1982, Hering 1997, Romberg & Davis 2007, Sandoval-Denis et al. 2018). Morphologically, N. noneumartii fits the modern concepts of ‘Fusarium’ eumartii sensu Wollenweber (1943) and sensu Gerlach & Nirenberg (1982) by forming large, multiseptate (up to 6-septate) sporodochial conidia. Nevertheless, a re-examination of the original material of F. eumartii showed that the species differs sharply from the previously mentioned modern concept, and this name is here reduced to synonymy under N. solani. As stated in earlier circumscriptions of the two species (Sherbakoff 1915, Wollenweber & Reinking 1935a), this synonymy is also supported by our phylogenetic analyses of the original material of F. eumartii. Therefore, N. noneumartii is proposed here as a novel species.

The sporodochial conidia of N. noneumartii are similar in size and septation to those of N. ampla and N. quercicola. These three species include strains that were, historically, identified as F. eumartii based on the broad modern concept of this species. However, N. noneumartii can be distinguished from N. quercicola by the latter’s absence of aerial falcate, multiseptate conidia. Neocosmospora quercicola produces only microconidia on its aerial conidiophores and also produces sporodochial conidia with somewhat elongated foot cells. The cultural characteristics of N. noneumartii and N. ampla appear to be similar, as is the range of conidia produced by both species, although the sporodochial conidia of N. noneumartii are usually slender, with somewhat longer apical cells.

Neocosmospora oblonga Sand.-Den. & Crous, sp. nov. — MycoBank MB831191; Fig. 28

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Fig. 28.

Neocosmospora oblonga (ex-type culture CBS 130325). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–g. conidiophores; h–i. chlamydospores; j–k. conidia. — Scale bars: c–d = 20 μm; h–i = 5 μm; all others = 10 μm.

Etymology. From Latin oblongum meaning ‘prolate spheroid’; referring to its conidial shape.

Typus. USA, from human eye, unknown date and collector (holotype CBS H-23990 designated here, culture ex-type CBS 130325 = NRRL 28008 = CDC B-4701).

Conidiophores abundant on aerial and substrate mycelium, straight, smooth- and thin-walled, commonly simple or moderately dichotomously, verticillately, or irregularly branched, often proliferating, bearing terminal, single monophialides; phialides subulate, subcylindrical to acicular, (3.5–)13.3–26.5(–33.5) × (0.5–)1–1.5 μm (av. 19.9 × 1.2 μm, n = 76), hyaline, smooth- and thick-walled, conidiogenous loci with visible periclinal thickening and a short, flared or non-flared collarette; aerial conidia ellipsoidal, clavate or bullet shaped, rarely short falcate, 0(–1)-septate, hyaline, smooth- and thin-walled, (5–)8–14(–22) × (2–)3–4(–5.5) μm (av. 10.9 × 3.3 μm, n = 178), clustering in false heads at tip of monophialides. Sporodochia not seen. Chlamydospores abundant, globose to subglobose, smooth- to finely verruculose and thick-walled, (5.5–)6–7.5(–8) μm diam, terminal or intercalary in hyphae or conidia, solitary or in chains. Colonies on PDA growing in dark with an average radial growth rate of 2.3–3 mm/d at 24 °C, reaching 16–21 mm diam in 7 d at 24 °C; white to pale straw at margin, flat, velvety to finely dusty or granular; margin lobate and highly irregular. Reverse pale straw to pale luteous. On OA incubated in dark reaching 16–20 mm diam in 7 d at 24 °C; white, flat, velvety to dusty; margin entire. Reverse saffron to rosy buff.

Notes — Neocosmospora oblonga is introduced here for the clade informally known as phylogenetic species FSSC 29 (O’Donnell et al. 2008). The isolate studied here (CBS 130325) produces microconidia only, while no sporodochia were observed. This lineage was included in the ‘F. ensiforme clade’ by Nalim et al. (2011). However, despite its simple morphology, cultural and micromorphological features this novel species is distinct from any plausible concept of F. ensiforme, an obscure name of uncertain application. Conidia of N. oblonga are typically ellipsoidal to clavate and straight, although short, falcate, 1-septate conidia can also rarely be observed on the aerial phialides. In contrast, F. ensiforme is described as forming mostly unicellular, ovoid and slightly curved microconidia and long, up to 7-septate sporodochial conidia. Additionally, the colonies of F. ensiforme grown on OA were reported to develop a thick and dense pink to buff-coloured mycelium, contrasting with the white and short aerial mycelium seen in N. oblonga (Wollenweber & Reinking 1925, Reinking & Wollenweber 1927). For additional comparisons, see notes under N. parceramosa.

Neocosmospora oligoseptata (T. Aoki et al.) Sand.-Den. & Crous, comb. nov. — MycoBank MB831192

Basionym. Fusarium oligoseptatum T. Aoki et al., Fungal Systematics and Evolution 1: 29. 2018.

Typus. USA, Pennsylvania, Dauphin Co., from a live female ambrosia beetle (Euwallacea validus), extracted from a gallery in a tree-of-heaven (Ailanthus altissima), 30 Jan. 2010, M.T. Kasson (holotype BPI 910525, culture ex-type CBS 143241 = NRRL 62579 = FRC S-2581 = MAFF 246283).

Description & Illustration — Aoki et al. (2018).

Notes — Neocosmospora oligoseptata is here coined for the recently described F. oligoseptatum. This species is a well-recognised and characterised phylogenetic species (as AF-1) within the Ambrosia clade of Neocosmospora. This clade is known to include symbionts of Euwallacea validus (Curculionidae: Xyleborini), an ambrosia beetle known from Asia and North America, and commonly associated with the transmission of Verticillium nonalfalfae, the agent of Verticillium wilt on the invasive tree-of-heaven (Ailanthus altissima; Cognato et al. 2015, Kasson et al. 2015).

According to Aoki et al. (2018), N. oligoseptata forms irregularly falcate to clavate, apically swollen sporodochial conidia similar to those of N. ambrosia and N. euwallaceae. However, N. oligoseptata can be distinguished by frequently producing 0–2-septate sporodochial conidia instead of the more regularly 3–5-septate sporodochial conidia of other species in this clade.

Neocosmospora paraeumartii Sand.-Den. & Crous, sp. nov. — MycoBank MB831193; Fig. 29

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Fig. 29.

Neocosmospora paraeumartii (ex-type culture CBS 487.76). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–e. sporodochia formed on the surface of carnation leaves; f–h. aerial conidiophores; i. aerial conidia; j. sporodochial conidiophore; k–l. sporodochial conidia. — Scale bars: c–e = 100 μm; f–h = 20 μm; all others = 10 μm.

Etymology. From Greek (pará), meaning ‘against, contrary to’. According to the modern morphological concept of F. eumartii, the ex-type culture N. paraeumartii was erroneously thought to represent this historic species.

Typus. Argentina, from decaying stem base of Solanum tuberosum, unknown date or collector (holotype CBS H-23991 designated here, culture ex-type CBS 487.76 = NRRL 13997 = BBA 62215).

Conidiophores abundant on the aerial mycelium, erect or prostrate on vegetative mycelium, smooth- and thin-walled, at first simple, later sparingly and irregularly branched, bearing terminal monophialides; phialides subulate to subcylindrical, (16–)35.5–60(–67) × 2–3(–3.5) μm (av. 48 × 2.7 μm, n = 28), smooth- and thin-walled, conidiogenous loci with inconspicuous periclinal thickening and a short, non-flared collarette; aerial conidia ellipsoidal to subcylindrical, often dorsiventrally curved, 0(–1)-septate, hyaline, smooth- and thin-walled, (5–)6.5–11.5(–16.5) × (2.5–)3–4.5(–5.5) μm (av. 9 × 3.7 μm, n = 91), grouped in false heads on tip of monophialides. Sporodochia cream, ochreous to pale green. Sporodochial conidiophores densely and irregularly branched; sporodochial phialides ampulliform, subcylindrical to subulate, (12–)15–21(–22) × 3.5–5(–5.5) μm (av. 18 × 4.3 μm, n = 34), smooth- and thin-walled, conidiogenous loci with inconspicuous periclinal thickening and a minute, non-flared collarette. Sporodochial conidia almost straight, discreetly to moderately dorsiventrally curved, wedge-shaped; apical cell of more or less equal length than adjacent cell, apex blunt and often distinctly hooked; basal cell notched and moderately protuberant (1–)4–6-septate, hyaline, smooth- and thick-walled; 1-septate conidia: 22.5 × 4 μm (n = 2); 3-septate conidia: (34–)35.5–48(–50) × 4.5–5.5 μm (av. 41.7 × 5 μm, n = 6); 4-septate conidia: (39.5–)49–64(–65) × (5–)5.5–6(–7) μm (av. 56.5 × 5.9 μm, n = 40); 5-septate conidia: (52.5–)56–66(–73) × 5–6(–6.5) μm (av. 61 × 5.8 μm, n = 88); 6-septate conidia: (57.5–)60.5–73(–75.5) × 5.5–6.5 μm (av. 66.6 × 5.9 μm, n = 44); overall: (22.5–)48.5–69(–75.5) × (4–)5–6.5(–7) μm (av. 58.9 × 5.8 μm, n = 180). Chlamydospores subglobose to globose, smooth- or rough- and thick-walled, 5–12.5 μm diam, terminal or intercalary.

Colonies on PDA growing in dark with an average radial growth rate of 2.8–3.1 mm/d at 24 °C, reaching 38–42 mm diam in 7 d at 24 °C; white, pale luteous to luteous at centre, flat to slightly raised, felty to cottony, with abundant irregularly distributed aerial mycelium; colony margin filiform. Reverse pale straw to pale luteous. On OA incubated in dark reaching 36–45 mm diam in 7 d at 24 °C; straw to buff, flat, membranous with scant white aerial mycelium; margin entire. Reverse buff.

Notes — This species is based on a single isolate that is genetically and morphologically well-delimited. The ex-type of N. paraeumartii was illustrated as representative of F. eumartii by Gerlach & Nirenberg (1982). The latter taxon is synonymised here under N. solani based on morphological and phylogenetic analyses of a specimen derived from the type material of F. eumartii (see notes under N. solani).

Morphologically, N. paraeumartii is comparable to, i.e., N. ampla, N. nirenbergiana, N. noneumartii and N. quercicola. All these species display morphologies concordant with the modern concept of F. eumartii, characterised by robust, predominantly 5–7-septate sporodochial conidia. However, these morphological features are highly polyphyletic in Neocosmospora.

Neocosmospora paraeumartii is phylogenetically distant and unrelated to all of the above-mentioned species. In addition, N. paraumartii differs from N. ampla, N. nirenbergiana and N. noneumartii by the absence of aerial macroconidia. The sporodochial conidia in N. ampla and N. nirenbergiana are much wider (av. 6.3 and 6.6 μm wide, respectively) than those of N. paraeumartii, while N. nirenbergiana clusters in Clade 2. The distinction between N. paraeumartii and N. quercicola is virtually impossible based on morphology alone. The sporodochial conidia of N. paraeumartii display a slightly more pronounced curvature than those of N. quercicola. Although both species are easily distinguished genetically, morphological measurements largely overlap.

Neocosmospora parceramosa Sand.-Den. & Crous, sp. nov. — MycoBank MB831194; Fig. 30

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Fig. 30.

Neocosmospora parceramosa (ex-type culture CBS 115695). a–b. Colonies on PDA and OA, respectively, after 14 d at 24 °C in the dark; c–h. conidiophores; i. chlamydospores; j–k. conidia. — Scale bars: c–d = 20 μm; all others = 10 μm.

Etymology. From Latin parce, meaning ‘sparingly, moderately’; and rāmus, meaning ‘branch’. After its sparingly branched conidiophores.

Typus. South Africa, from soil, 1995, unknown collector (holotype CBS H-23992 designated here, culture ex-type CBS 115695 = CPC 1246).

Conidiophores on the substrate and aerial mycelium straight or flexuous, smooth- and thin-walled, mostly simple or sparingly branched, bearing terminal, single monophialides; phialides subulate to subcylindrical, (35–)47.5–63.5(–74) × (2–)2.5–3.5(–4) μm (av. 55.5 × 2.9 μm, n = 84), smooth- and thin-walled, conidiogenous loci with conspicuous periclinal thickening and a short, somewhat flared collarette; aerial conidia ellipsoidal, subcylindrical to clavate, straight, gently curved or rarely apically hooked, 0(–1)-septate, hyaline, smooth- and thin-walled, (4–)5.5–10(–16) × (2.5–)3–4(–5) μm (av. 7.9 × 3.4 μm, n = 169), clustering in false heads on tip of monophialides. Sporodochia not observed. Chlamydospores globose to subglobose, smooth-walled, warted or tuberculate and thick-walled, (5.5–)6–7.5(–8.5) μm diam, terminal, intercalary or more often borne on short lateral hyphal pegs, solitary or in chains.

Colonies on PDA growing in dark with an average radial growth rate of 3.2–3.5 mm/d at 24 °C, reaching 44–50 mm diam in 7 d at 24 °C; white to pale straw, flat, velvety, cottony to felty, with concentric rings of white to pale straw aerial mycelium; margin entire. Reverse straw to honey. On OA incubated in dark reaching 63–78 mm diam in 7 d at 24 °C; white, flat, velvety to granular with concentric rings of dense, white aerial mycelium; margin entire. Reverse straw to buff.

Notes — Neocosmospora parceramosa, previously known as phylogenetic species FSSC 18, has been mostly isolated as a putative rare human pathogen (O’Donnell 2000) which requires further investigation. Neocosmospora parceramosa is also known to inhabit plumbing systems (Short et al. 2011), while the type was obtained from an environmental soil sample in South Africa. The ex-type strain, an isolate producing only microconidia from aerial conidiophores was originally identified and deposited as a Verticillium sp., which may indicate that the lack of sporodochia is not a result of strain deterioration after long-term storage, but a distinctive feature of the species.

Identifying species that only produce simple aerial conidiophores and lacking sporodochial conidia, i.e., N. catenata, N. diminuta, N. liriodendri, N. oblonga, N. parceramosa and N. vasinfecta, can be problematic. Neocosmospora diminuta differs conspicuously by the noticeable production of a sexual morph, an attribute shared with N. vasinfecta, distinguished by producing aseptate ascospores contained in smooth-walled, bright red perithecia. Distinctively, N. diminuta can produce falcate, multiseptate aerial conidia. Neocosmospora catenata commonly exhibits conspicuous chains of pale brown chlamydospores and rather dramatically flared phialidic collarettes. Neocosmospora parceramosa and N. oblonga are phylogenetically well-defined, even though the two species exhibit similar macroscopic features, in addition to having overlapping conidial and chlamydospore features. The main distinguishing morphological features of N. parceramosa include a fast growth rate on OA at 24 °C (63–78 vs 16–20 mm diam at 7 d in N. oblonga) and the very long phialides up to 74 μm vs up to 33.5 μm long in N. oblonga. Likewise, N. parceramosa can be distinguished from N. liriodendri by its faster growth rate on artificial media; longer aerial phialides (up to 71.5 μm long in N. liriodendri); and shorter, smooth to tuberculate chlamydospores (up to 8.5 vs up to 10.5 μm diam, and smooth-walled in N. liriodendri).

Neocosmospora perseae Sand.-Den. & Guarnaccia, Fungal Systematics and Evolution 1: 136. 2018

Typus. Italy, Catania, San Leonardello, from trunk canker lesions on Persea americana, 25 Mar. 2015, G. Polizzi (holotype CBS H-23433, culture ex-type CBS 144142 = CPC 26829).

Description & Illustration — Guarnaccia et al. (2018).

Additional material examined. Italy, Catania, San Leonardello, from trunk canker lesions on Persea americana, 25 Mar. 2015, G. Polizzi, CBS 144143 = CPC 26830, CBS 144144 = CPC 26831, CBS 144145 = CPC 26832, CBS 144146 = CPC 26833.