DNA isolation, amplification and sequence analysis

Fungal colonies were established on agar plates, and genomic DNA was isolated as described in Gams et al. (2007). Partial gene sequences were determined as described by Crous et al. (2006) for actin (ACT), calmodulin (CAL), translation elongation factor 1-alpha (EF), histone H3 (HIS) and part (ITS) of the nuclear rDNA operon spanning the 3' end of the 18S rRNA gene (SSU), the first internal transcribed spacer, the 5.8S rRNA gene, the second internal transcribed spacer and the 5' end of the 28S rRNA gene (LSU). The nucleotide sequences were generated using both PCR primers to ensure good quality sequences over the entire length of the amplicon. Subsequent sequence alignment and phylogenetic analysis followed the methods of Crous et al. (2006). Gaps longer than 10 bases were coded as single events for the phylogenetic analyses; the remaining gaps were treated as new character states. Sequence data were deposited in GenBank (Table 1) and the alignment and tree in TreeBASE (www.treebase.org).

Data analysis

The number of entities in the dataset of 79 strains was inferred with Structure v. 2.2 software (Pritchard et al. 2000, Falush et al. 2003) using an UPGMA tree of data of the ACT gene compared with CAL, EF and HIS with the exclusion of the nearly invariant ITS region. For this analysis group indications were derived from a tree produced with MrAic (Nylander 2004). The length of the burn-in period was set to 1 000 000, number of MCMC repeats after burn-in 10 000, with admixture ancestry and allele frequencies correlated models, assuming that all groups diverged from a recent ancestral population and that allele frequencies are due to drift. Uniform prior for ALPHA was set to 1.0 (default) and allele frequencies with λ set to 1.0 (default). The numbers of MCMC repetitions after burn-in were set as 10 000 and 100 000. The number of clusters (K) in Structure was assumed from 5 to 7. Population differentiation F_ST (index: θ) was calculated with 1-6 runs using the same software. The null hypothesis for this analysis is no population differentiation. When observed theta (θ) is significantly different from those of random data sets (p < 0.05), population differentiation is considered.

Association of multilocus genotypes was screened with the multilocus option in BioNumerics v. 4.5. To test for reproductive mode in each population, the standardised index of association (I⁵_A; Haubold et al. 1998) was calculated with start2 software (Jolley et al. 2001). The null hypothesis for this analysis is complete panmixia. The values of I^S_A were compared between observed and randomised datasets. The hypothesis would be rejected when p < 0.05. Mean genetic diversity (H) and diversities of individual loci were calculated with lian v. 3.5 (Haubold & Hudson 2000). Degrees of recombination or horizontal gene transfer were also visualised using Splits Tree v. 4.8 software (Huson & Bryant 2006). Split decomposition was carried out with default settings, i.e., character transformation using uncorrected (observed, “P”) distances, splits transformation using “equal angle”, and optimise boxes iteration set to 2.

Morphology

As the present study represents the first in a series dealing with Cladosporium spp. and their Davidiella Crous & U. Braun teleomorphs in culture, a specific, standardised protocol was established by which all species complexes will be treated in future.

Morphology of the anamorph: Microscopic observations were made from colonies cultivated for 7 d under continuous near-ultraviolet light at 25 °C on SNA. Preparations were mounted in Shear's solution (Gams et al. 2007). To study conidial development and branching patterns, squares of transparent adhesive tape (Titan Ultra Clear Tape, Conglom Inc., Toronto, Canada) were placed on conidiophores growing in the zone between the colony margin and 2 cm inwards, and mounted between two drops of Shear's solution under a glass coverslip. Different types of conidia are formed by Cladosporium species for which different terms need to be adopted. Ramoconidia are conidia with usually more than one (mostly 2 or 3) conidial hilum, which typically accumulate at the tip of these conidia. Conidiogenous cells with more than one conidiogenous locus are first formed as apical parts of conidiophores. Such apical parts of conidiophores are called ramoconidia if they secede at a septum from the conidiophore (Kirk et al. 2001). The septum at which the ramoconidium secedes often appears to be somewhat refractive or darkened. Ramoconidia are characterised by having a truncate, undifferentiated base (thus they lack a differentiated, coronate basal hilum formed in the context of conidiogenesis) and they can be very long, aseptate to sometimes multi-septate. Although they were formed initially as part of the conidiophore, they function as propagules. Only few of the species known until now have the ability to form true ramoconidia. Secondary ramoconidia also have more than one distal conidial hilum but they always derive from a conidiogenous locus of an earlier formed cell, which can be either a conidiogenous cell or a ramoconidium. Secondary ramoconidia are often shorter but somewhat wider than ramoconidia; they are often septate, and typically have a narrowed base with a coronate hilum (Fig. 1). Conidia in Cladosporium are cells with a coronate basal hilum, which is formed in the context of conidiogenesis and with either a single (when formed as intercalary units in unbranched parts of chains) or without any distal conidial hilum (when formed at the tip of conidial chains). For the first, the term “intercalary conidium” and for the latter, “small terminal conidium” is used. Intercalary conidia typically are larger and more pigmented and have a more differentiated surface ornamentation than the small terminal conidia. In older literature true ramoconidia were often cited as “ramoconidia s. str.”, whereas secondary ramoconidia have been referred to as “ramoconidia s. lat.” Morphology of the teleomorph: Teleomorphs were induced by inoculating plates of 2 % tap water agar onto which autoclaved stem pieces of Urtica dioica (European stinging nettle) were placed. Inoculated plates were incubated on the laboratory bench for 7 d, after that period they were further incubated at 10 °C in the dark for 1-2 mo to stimulate teleomorph development. Wherever possible, 30 measurements (× 1 000 magnification) were made of conidia and ascospores, with the extremes of spore measurements given in parentheses. Cultural characteristics: Colonies were cultivated on PDA, MEA and OA plates for 14 d at 25 °C in the dark, after which the surface and reverse colours were rated using the charts of Rayner (1970). Linear growth was determined on MEA, PDA and OA plates by inoculating three plates per isolate for each medium, and incubating them for 14 d at 25 °C, after that period colony diameters were determined.

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Fig. 1.

Cladosporium conidiophore with ramoconidia, secondary ramoconidia, intercalary conidia, and small, terminal conidia. Scale bar = 10 μm. K. Schubert del.

Key to the Davidiella species treated

• 1. Ascospores frequently wider than 7 μm when mounted in Shear's solution or lactic acid, apical cell obtusely rounded................................................................................................................................................................................................................... 2

• 1. Ascospores not wider than 7 μm when mounted in Shear's solution or lactic acid, apical cell acutely rounded, ascospores (20-)25-27 (-30) × (5.5-)6-7 μm................................................................................................................................................................. D. allicina

• 2. Pseudoparaphyses prominent; asci frequently >95 μm; ascospores (22-)23-26(-28) × (6-)6.5-7(-8) μm..................... D. macrocarpa

• 2. Pseudoparaphyses mostly absent in older ascomata; asci <95 μm......................................................................................................... 3

• 3. Ascospores (22-)26-30(-35) × (7-)7.5-8(-9) μm; asci wider than 18 μm............................................................................. D. variabile

• 3. Ascospores (17-)20-23(-25) × (6-)7(-8) μm; asci not wider than 18 μm.............................................................................. D. tassiana

Generic concept of the teleomorph

The introduction of the teleomorph genus Davidiella was mainly based on phylogenetic studies within the Mycosphaerellaceae (Braun et al. 2003), where it could be demonstrated that “Mycosphaerella” species with Cladosporium anamorphs formed a sister clade to Mycosphaerella (Crous et al. 2000, 2001). Braun et al. (2003) transferred five species to Davidiella based on prior established anamorph-teleomorph connections, though no details were provided pertaining to morphological differences between Davidiella and Mycosphaerella. Aptroot (2006) transferred several additional species to Davidiella, and distinguished them from true Mycosphaerella species by the presence of distinct, irregular cellular inclusions (lumina) in their ascospores. Furthermore, Schoch et al. (2006) placed Davidiella in a separate family (Davidiellaceae) in the Capnodiales. During the course of the present study, several fresh specimens of Davidiella spp. were collected or induced in culture, making it possible to circumscribe the genus as follows:

Davidiella Crous & U. Braun, Mycol. Progr. 2: 8. 2003, emend.

Ascomata pseudothecial, black to red-brown, globose, inconspicuous and immersed beneath stomata to superficial, situated on a reduced stroma, with 1(-3) short, periphysate ostiolar necks; periphysoids frequently growing down into cavity; wall consisting of 3-6 layers of textura angularis. Asci fasciculate, short-stalked or not, bitunicate, subsessile, obovoid to broadly ellipsoid or subcylindrical, straight to slightly curved, 8-spored. Pseudoparaphyses frequently present in mature ascomata, hyaline, septate, subcylindrical. Ascospores bi- to multiseriate, hyaline, obovoid to ellipsoid-fusiform, with irregular luminar inclusions, mostly thick-walled, straight to slightly curved; frequently becoming brown and verruculose in asci; at times covered in mucoid sheath. Cladosporium anamorph usually produced in culture, but not in all taxa.

Type species: Davidiella tassiana (De Not.) Crous & U. Braun, Mycol. Progr. 2: 8. 2003.

Description of Cladosporium species

Based on morphological examinations (David 1997) and phylogenetic studies employing DNA sequence data (Crous et al. 2000, 2001, 2007 - this volume, Braun et al. 2003), the generic concept of the genus Cladosporium has been stabilised. Cladosporium is confined to Davidiella (Davidiellaceae, Capnodiales) anamorphs with coronate conidiogenous loci and conidial hila consisting of a central convex dome and a raised periclinal rim.

Cladosporium antarcticum K. Schub., Crous & U. Braun, sp. nov. MycoBank MB504573. Figs ​Figs6, 6, ​,77 and ​and88.

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Fig. 6.

Cladosporium antarcticum (CBS 690.92). Macro- and micronematous conidiophores and conidia. Scale bar = 10 μm. K. Schubert del.

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Fig. 7.

Cladosporium antarcticum (CBS 690.92). A. Overview of the growth pattern on SNA. Note the very large bulbous cells formed at the base of different conidiophores. Other conidiophores sprout from the agar surface. B. Overview of conidiophores and conidia. Note the large distance of the scars on the conidiophore and the different stages of conidial formation on the tips of other conidia. The long secondary ramoconidia are also visible, and sparse aerial hyphae. C. Detail of B with details of the ornamentation and scars. The absence of ornamentation at the apical (spore-forming) end of the secondary ramoconidium is clearly visible. D-E. Tubular structures on coniophore (D) and secondary ramoconidium (E). Scale bars: A-B = 10 μm, C-D = 5 μm, E = 2 μm.

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Fig. 8.

Cladosporium antarcticum (CBS 690.92). A-B. Macronematous conidiophores. C, G. Mycelium enveloped by a polysaccharide-like layer. D, F. Conidia. E. Micronematous conidiophore. H. Ramoconidium with numerous distal scars. Scale bars = 10 μm.

Etymology: Refers to Antarctica, where the fungus was collected.

Differt a Cladosporio licheniphilo conidiophoris saepe non-ramosis, frequentibus geniculatis, angustioribus, (2-)3-4.5 μm, conidiis longioribus et angustioribus, 4-30 × 2.5-5 μm, 0-3-septatis, verruculosis vel verrucosis.

Mycelium immersed and superficial, dimorphic, branched, often with short lateral outgrowths, narrow hyphae 1-3 μm wide, hyaline to subhyaline, thin-walled, hyphae of the second type wider, 3.5-8(-9) μm, pluriseptate, often somewhat constricted at the septa, sometimes swollen, pale to dark greyish olivaceous or olivaceous-brown, smooth or verruculose, thick-walled, sometimes even two-layered (two distinct wall layers visible), 1(-1.5) μm thick, hyphae appearing consistently enveloped in polysaccharide-like material or covered by a slime coat. Conidiophores micronematous and macronematous, solitary or in loose groups, arising from plagiotropous or ascending hyphae, terminally or usually laterally. Macronematous conidiophores erect to somewhat decumbent, straight to somewhat flexuous or bent, cylindrical, once or several times slightly to distinctly geniculate towards the apex due to sympodial proliferation, unbranched or once branched, up to 120 μm long, 3-4.5 μm wide, sometimes slightly attenuated towards the apex, pluriseptate, up to eight septa, occasionally slightly constricted at the septa, pale to medium or even dark olivaceous-brown or greyish brown, paler towards apices, smooth to somewhat rough-walled, walls thickened but thinner-walled towards apices, sometimes slightly swollen at the base, up to 6 μm wide. Conidiogenous cells integrated, terminal and intercalary, once or several times slightly to distinctly geniculate, 10-33 μm long, proliferation sympodial, with several or numerous conidiogenous loci, at first terminal, later turning to one side of the stalk and situated on small lateral shoulders, up to 14 per cell, protuberant, denticulate, 1-1.5(-2) μm diam, thickened and darkened-refractive. Micronematous conidiophores as short lateral, peg-like outgrowths with a single apical scar or somewhat longer, occasionally once geniculate with several conidiogenous loci at the apex, 2-22 × 2-3 μm, pale greyish olivaceous, loci denticulate. Ramoconidia occasionally occurring, cylindrical, up to 30 μm long, 4-5 μm wide, 0-1-septate, concolorous with the tips of conidiophores, with a broadly truncate, unthickened and not darkened base, without dome and rim, 2.5 μm wide. Conidia catenate, in branched chains, straight, small terminal conidia obovoid, limoniform or narrowly ellipsoid, 4-14 × 2.5-4 μm [av. ± SD, 8.5 (± 3.3) × 3.5 (± 0.6)], 0(-1)-septate, secondary ramoconidia ellipsoid to cylindrical, often with several or numerous conidial hila crowded at the distal end, up to 12, 13-30 × 4-5 μm [av. ± SD, 20.1 (± 5.8) × 4.3 (± 0.5) μm], 0-3-septate, sometimes slightly constricted at the median septum, pale olivaceous-brown or greyish brown, minutely verruculose to verrucose (granulate under SEM), walls more or less thickened, rounded or slightly attenuated towards apex and base, hila protuberant, denticulate, 0.8-1.5(-2) μm diam, thickened and darkened-refractive; microcyclic conidiogenesis occurring.

Cultural characteristics: Colonies on PDA attaining 9 mm diam after 14 d at 25 °C, greenish olivaceous to grey-olivaceous, at the margin becoming dull green, reverse with a pale olivaceous-grey centre and a broad olivaceous-black margin, margin narrow, regular, entire edge, white, feathery, aerial mycelium sparse but colonies appearing felty, growth flat with somewhat elevated colony centre, prominent exudates not formed, sporulation dense, covering almost the whole colony. Colonies on MEA attaining 12 mm diam after 14 d at 25 °C, olivaceous-grey to iron-grey, iron-grey reverse, velvety to powdery, aerial mycelium sparse, sporulation profuse. Colonies on OA attaining 4 mm after 14 d at 25 °C, olivaceous-grey, aerial mycelium sparse, diffuse, growth flat, without prominent exudates, sporulating.

Specimen examined: Antarctica, King George, Arctowski, isolated from the lichen Caloplaca regalis (Teloschistaceae), C. Möller, No. 32/12, 1991, CBS-H 19857, holotype, isotype HAL 2024 F, culture ex-type CBS 690.92.

Substrate and distribution: On the lichen Caloplaca regalis; Antarctica.

Notes: This is the second genuine lichenicolous species of the genus Cladosporium. Cladosporium licheniphilum Heuchert & U. Braun, occurring on apothecia of Pertusaria alpina in Russia, is quite distinct from C. antarcticum by having subcylindrical or only slightly geniculate-sinuous, wider conidiophores, 5-8 μm, with numerous characteristic terminal branches and much shorter, 0-1-septate, smooth conidia, 3.5-13 × 3-7 μm (Heuchert & Braun 2006). Cladosporium lichenicola Linds. was invalidly published and C. arthoniae M.S. Christ. & D. Hawksw. as well as C. lichenum Keissl. are to be excluded from the genus Cladosporium since they do not possess the typical cladosporioid scar structure but inconspicuous, unthickened conidiogenous loci and conidial hila (Hawksworth 1979, Heuchert et al. 2005). The fungicolous species C. uredinicola Speg. and the foliicolous species C. alneum Pass. ex K. Schub. and C. psoraleae M.B. Ellis are morphologically superficially similar. However, C. uredinicola, a widespread fungus on rust fungi, downy mildews and powdery mildew fungi, differs in having somewhat longer and wider, smooth conidia, 3-39 × 2-6.5(-8) μm, and wider conidiogenous loci and conidial hila, 0.5-3 μm (Heuchert et al. 2005); C. alneum, which causes leaf spots on Alnus glutinosa, possesses longer and wider conidiophores, 25-260 × (2-)3-7(-8.5) μm, and somewhat shorter, smooth conidia (Schubert 2005, Schubert et al. 2006); and C. psoraleae, known from Myanmar on Psoralea corylifolia, can easily be distinguished from C. antarcticum by its smooth and wider conidia, 3.5-7 μm, and wider conidiogenous loci and conidial hila, 1-3 μm diam (Ellis 1972, Schubert 2005).

Cladosporium bruhnei Linder, Bull. Natl. Mus. Canada 97: 259. 1947. Figs ​Figs9, 9, ​,10, 10, ​,1111 and ​and1212.

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Fig. 9.

Cladosporium bruhnei (CPC 12211). Macro- and micronematous conidiophores and conidia. Scale bar = 10 μm. K. Schubert del.

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Fig. 10.

Cladosporium bruhnei (CPC 12211). A. Conidiophore with characteristic long secondary ramoconidium and complex conidiophore. B. Detail of hila on secondary ramoconidia. C. Details of prominent ornamentation on conidia. Scale bars: A = 10 μm, B = 2 μm, C = 5 μm.

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Fig. 11.

Davidiella allicina (F-09810, UPS-FRIES, holotype). Ascus and ascospores. Scale bar = 10 μm. P.W. Crous del.

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Fig. 12.

Cladosporium bruhnei (CPC 12211) and its teleomorph Davidiella allicina. A-B. Macronematous conidiophores. C. Conidial chains. D. Micronematous conidiophore. E. Ascomata of the teleomorph formed on the host. F-G. Asci. Scale bars: A-B, D, F = 10 μm, E = 200 μm.

• ≡ Hormodendrum hordei Bruhne, in W. Zopf, Beitr. Physiol. Morph. nied. Org. 4: 1. 1894, non C. hordei Pass., 1887.

• ≡ Cladosporium herbarum (Pers.: Fr.) Link var. (δ) cerealium Sacc. f. hordei (Bruhne) Ferraris, Flora Ital. Crypt., Pars I, Fungi, Fasc.13: 882. 1914.

• ≡ Cladosporium hordei (Bruhne) Pidopl., Gribnaja Flora Grubych Kormov: 268. 1953, nom. illeg., homonym, non C. hordei Pass., 1887.

Teleomorph: Davidiella allicina (Fr.: Fr.) Crous & Aptroot, in Aptroot, Mycosphaerella and its anamorphs: 2. Conspectus of Mycosphaerella. CBS Biodiversity Ser. 5: 30. 2006.

Basionym: Sphaeria allicina Fr., Kongl. Vetensk. Acad. Handl. 38: 247. 1817, sactioned by Fr., Syst. Mycol. 2: 437. 1823.

• ≡ Sphaerella allicina (Fr.: Fr.) Auersw., in Gonn. & Rabenh., Mycol. Europaea 5-6: 19. 1869.

Ascomata pseudothecial, black, superficial, situated on a small stroma, globose, up to 250 μm diam; ostioles periphysate, with apical periphysoids present; wall consisting of 3-6 layers of reddish brown textura angularis. Asci fasciculate, bitunicate, subsessile, obovoid to broadly ellipsoid, straight to slightly curved, 8-spored, 65-90 × 16-25 μm; with pseudoparenchymatal cells of the hamathecium persistent. Ascospores tri- to multiseriate, overlapping, hyaline, with irregular lumina, thick-walled, straight to slightly curved, fusoid-ellipsoidal with obtuse basal end, and acutely rounded apical end, widest near the middle of the apical cell, medianly 1-septate, not to slightly constricted at the septum, (20-)25-27(-30) × (5.5-)6-7 μm.

Mycelium superficial, hyphae branched, 1.5-8 μm wide, pluriseptate, broader hyphae usually slightly constricted at the septa and somewhat swollen, hyaline to subhyaline, almost smooth to somewhat verruculose or irregularly rough-walled, sometimes appearing to have a slime coat, walls unthickened. Conidiophores macronematous, sometimes also micronematous, arising as lateral or terminal branches from plagiotropous or ascending hyphae, erect, straight to more or less flexuous, sometimes geniculate, nodulose, usually with small head-like swellings, sometimes also with intercalary nodules, sometimes swellings protruding and elongated to one side, unbranched, occasionally branched, (7-)20-330 μm, sometimes even longer, (2-)3-5 μm wide, swellings (4-)5-8 μm wide, pluriseptate, not constricted at the septa, septa sometimes not very conspicuous, subhyaline to pale brown or pale olivaceous, smooth or somewhat verruculose, walls unthickened or almost so, more thickened with age. Conidiogenous cells integrated, usually terminal, cylindrical with a terminal head-like swelling, sometimes with a second swelling, 15-40 μm long, proliferation sympodial, with few conidiogenous loci confined to swellings, up to five per swelling, loci protuberant, conspicuous, 1-2 μm diam, thickened and darkened-refractive. Conidia catenate, formed in branched chains, straight to slightly curved, small terminal conidia subglobose, ovoid to obovoid or somewhat limoniform, 4-9 × 2.5-3.5 μm [av. ± SD, 6.5 (± 1.5) × 3.1 (± 0.5) μm], aseptate; secondary ramoconidia and occasionally formed ramoconidia ellipsoid to subcylindrical or cylindrical, 10-24(-31) × 3-5(-7) μm [av. ± SD, 16.1 (± 4.1) × 4.1 (± 0.8) μm], rarely up to 40 μm long, 0-1(-3)-septate, very rarely 5-septate, subhyaline to pale brown or pale olivaceous, minutely verruculose to verrucose (mostly granulate with some muricate projections under SEM), walls unthickened or almost so, apex rounded or slightly attenuated towards apex and base, hila protuberant, conspicuous, 1-2 μm wide, up to 1 μm high, thickened and darkened-refractive; microcyclic conidiogenesis occurring.

Cultural characteristics: Colonies on PDA reaching 22-32 mm diam after 14 d at 25 °C, olivaceous-grey to iron-grey, sometimes whitish, smoke-grey to pale olivaceous due to abundant aerial mycelium covering almost the whole colony, with age collapsing becoming olivaceous-grey, occasionally zonate, velvety to floccose, margin narrow, entire edge, white, glabrous to somewhat feathery, aerial mycelium sparse to abundant, white, fluffy, growth regular, flat to low convex, sometimes forming few exudates in the colony centre, sporulating. Colonies on MEA reaching 21-32 mm diam after 14 d at 25 °C, grey-olivaceous, olivaceous-grey to dull green or iron-grey, sometimes whitish to pale smoke-grey due to abundant aerial mycelium, olivaceous-grey to iron-grey reverse, velvety, margin narrow, entire edge to slightly undulate, white, radially furrowed, glabrous to slightly feathery, aerial mycelium sparse to abundant, mainly in the centre, white, fluffy, growth convex to raised, radially furrowed, distinctly wrinkled in the colony centre, without prominent exudates, sporulating. Colonies on OA reaching 20-32 mm diam after 14 d at 25 °C, smoke-grey, grey-olivaceous to olivaceous-grey, greenish black or iron-grey reverse, margin narrow, entire edge, colourless to white, glabrous, aerial mycelium sparse to abundant, dark smoke-grey, diffuse, high, later collapsed, felty, growth flat, without prominent exudates, sporulation profuse.

Specimens examined: Sine loco et dato, CBS 188.54 = ATCC 11290 = IMI 049638. Australia, N.S.W., Barrington Tops National Park, isolated from leaves of Eucalyptus stellulata (Myrtaceae), 3 Jan. 2006, B. Summerell, CPC 12921. Belgium, isolated from Quercus robur (Fagaceae), CBS 157.82; Kampenhout, isolated from Hordeum vulgare (Poaceae), 26 June 2005, J.Z. Groenewald, CBS-H 19856, neotype designated here of C. bruhnei, isoneotype HAL 2023 F, cultures ex-type CBS 121624 = CPC 12211, CPC 12212. Czech Republic, Lisen, isolated from Polygonatum odoratum (Liliaceae), CBS 813.71, albino mutant of CBS 812.71. Germany, CBS 134.31 = ATCC 11283 = IMI 049632; Nordrhein-Westfalen, Mühlheim an der Ruhr, isolated from industrial water, IWW 727, CBS 110024; Sachsen-Anhalt, Halle (Saale), Robert-Franz-Ring, isolated from leaves of Tilia cordata (Tiliaceae), 2004, K. Schubert, CPC 11386. Netherlands, isolated from air, CBS 521.68; isolated from Hordeum vulgare, 1 Jan. 2005, P.W. Crous, CPC 12139; isolated from man, skin, CBS 159.54 = ATCC 36948; Amsterdam, isolated from Thuja tincture, CBS 177.71; Geleen, St. Barbara Ziekenhuis, isolated from man, skin, CBS 366.80, CBS 399.80; isolated from man, sputum, Aug. 1955, CBS 161.55. New Zealand, Otago, Lake Harris, isolated from Ourisia macrophylla (Scrophulariaceae), 30 Jan. 2005, A. Blouin, Hill 1135, CPC 11840. Russia, Moscow region, isolated from Polyporus radiatus (Polyporaceae), Oct. 1978, CBS 572.78 = VKM F-405. Slovenia, Ljubljana, isolated from an air conditioning system, 2004, M. Butala, EXF-680 = CPC 12046; Sečovlje, isolated from hypersaline water from salterns (reserve pond), 2005, P. Zalar, EXF-389 = CPC 12042. Spain, Ebro Delta, isolated from hypersaline water from salterns (crystallisation pond), 2004, P. Zalar, EXF-594 = CPC 12045. Sweden, Skåne, on tip blight of living leaves of Allium sp. (Alliaceae), Fr. no. F-09810, UPS-FRIES, holotype of Davidiella allicina. U.S.A., New York, Geneva, isolated from CCA-treated Douglas-fir pole, CBS 115683 = ATCC 66670 = CPC 5101.

Substrate and distribution: Living and decaying plant material, man, air, hypersaline and industrial water; widespread.

Literature: Saccardo (1899: 1076), Linder (1947: 289).

Notes: Cladosporium bruhnei proved to be an additional component of the herbarum complex. The species resembles C. herbarum s. str. as already stated by Linder (1947), but possesses consistently narrower conidia, usually 2.5-5 μm wide, and the conidiophores often form only a single apical swelling. The species was described by Bruhne (l.c.) as Hormodendrum hordei from Germany but type material could not be located. Linder (1947) examined No. 1481a-5 (Canada, N. Quebec, Sugluk, on Elymus arenarius var. villosus, 31 Jul. 1936, E. Meyer), presumably in the National Museum, and stated that this specimen agreed well with the description and illustration given by Bruhne (l.c.). Although the species occurs on numerous substrates and is widely distributed, it has not yet been recognised as a distinct species since it has probably been interpreted as a narrow variant of C. herbarum.

Based on morphology and DNA sequence data, the CBS strain CBS 177.71 chosen by Prasil & de Hoog (1988) as representative living strain of C. herbarum, rather clusters together with isolates of C. bruhnei. The strain CBS 813.71 is an albino mutant of the latter species as it does not appear to contain colour pigment. Furthermore, all isolates from humans treated until now as C. herbarum proved to be conspecific with the narrow-spored C. bruhnei.

Although Davidiella tassiana (ascospores 17-25 × 6-8.5 μm, RO) was treated as synonymous to D. allicina (ascospores 20-27 × 6-7 μm, UPS) in Aptroot (2006), they differ in apical ascospore taper, with ascospores of D. allicina being acutely rounded, while those of D. tassiana are obtusely rounded. The same ascospore taper was also observed in the teleomorph of C. bruhnei, and thus the name D. allicina is herewith linked to C. bruhnei, which is distinct from C. herbarum, having D. tassiana as teleomorph.

Cladosporium herbaroides K. Schub., Zalar, Crous & U. Braun, sp. nov. MycoBank MB504574. Figs ​Figs13, 13, ​,1414 and ​and1515.

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Fig. 13.

Cladosporium herbaroides (CPC 12052). Macro- and micronematous conidiophores and conidia. Scale bar = 10 μm. K. Schubert del.

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Fig. 14.

Cladosporium herbaroides (CPC 12052). A-B, D. Macronematous conidiophores. C. Conidial chain. E. Micronematous conidiophore. F. Microcyclic conidiogenesis. G. Conidia formed by micronematous conidiophores. Scale bars = 10 μm.

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Fig. 15.

Cladosporium herbaroides (CPC 12052). A. Overview of the growth characteristics of this fungus. Broad hyphae run over the surface of the agar, and possibly give rise to conidiophore branches. The conidiophores of this fungus can be rather long, resembling aerial hyphae. Clusters of conidia are clearly visible in this micrograph. B. The very wide surface hyphae can anastomose. C. Conidiophore with secondary ramoconidia and conidia. Note the variation in scar size. D. A very elaborate, complex conidiophore with different scars of variable size, one being more than 2 μm wide! E. Details of secondary ramoconidia and hila. Note the rather strong ornamentation in which smaller “particles” are between larger ones. F. Three conidia in a row. Note the scar formation in the chain and the reduction of the size of the cells throughout the spore-chain. The inset shows the resemblance of the scars on a conidiophore and on a secondary ramoconidium. Scale bars: A = 50 μm, B-C, F (inset) = 10 μm, D-E = 5 μm, F = 2 μm.

Etymology: Refers to its morphological similarity to Cladosporium herbarum.

Differt a Cladosporio herbaro conidiis polymorphis, 3-33 × (2-)3-6(-7) μm, postremo latioribus, (3.5-)5-9(-11) μm, fuscis et crassitunicatis; et a Cladosporio macrocarpo conidiophoris leniter angustioribus, 3-5 μm latis, nodulis angustioribus, 5-8 μm latis.

Mycelium branched, (1-)2-8 μm wide, septate, often with small swellings and constrictions, subhyaline to pale brown or pale olivaceous-brown, smooth or almost so to somewhat verruculose, walls unthickened or almost so. Conidiophores macronematous and micronematous, arising lateral from plagiotropous hyphae or terminally from ascending hyphae. Macronematous conidiophores erect, straight to slightly flexuous, often geniculate, nodulose, with unilateral or multilateral swellings, often numerous swellings in short succession giving them a gnarled appearance, often forming somewhat protruding or prolonged lateral swellings or a branch-like prolongation below the terminal swelling (due to sympodial proliferation), unbranched or sometimes branched, 30-230 μm long or even longer, 3-5 μm wide, swellings 5-8 μm wide, septate, not constricted at septa, pale to medium olivaceous-brown, smooth or almost so, walls slightly thickened. Conidiogenous cells integrated, terminal or intercalary, cylindrical, usually nodulose to nodose forming distinct swellings, sometimes geniculate, 15-55 μm long, with numerous conidiogenous loci usually confined to swellings or situated on small lateral shoulders, sometimes on the top of short peg-like prolongations or denticles, loci protuberant, 1-2 μm diam, thickened and darkened-refractive. Micronematous conidiophores much shorter, narrower, paler, neither nodulose nor geniculate, arising laterally from plagiotropous hyphae, often only as short lateral denticles or branchlets of hyphae, erect, straight, conical to cylindrical, unbranched, 3-65 × 2-3 μm, mostly aseptate, sometimes up to five septa, subhyaline, smooth, walls unthickened. Conidiogenous cells integrated, terminal or conidiophores reduced to conidiogenous cells, conidiogenous loci solitary or sometimes as sympodial clusters of pronounced denticles, protuberant, 1-1.5 μm diam, thickened and somewhat darkened-refractive. Conidia polymorphous, two main morphological types recognisable, formed by the two different types of conidiophores, conidia formed by macronematous conidiophores catenate, in branched chains, straight to slightly curved, subglobose, obovoid, limoniform, ellipsoid to cylindrical, 3-33 × (2-)3-6(-7) μm [av. ± SD, 14.5 (± 7.9) × 5.2 (± 1.2) μm], 0-2(-3)-septate, sometimes slightly constricted at septa, septa median or somewhat in the lower half, pale to medium olivaceous-brown, verruculose to verrucose (granulate under SEM), walls slightly thickened, with up to three rarely four distal scars, with age becoming medium or even dark brown (chocolate brown), wider and more thick-walled, 5.5-33 × (3.5-)5-9(-11) μm [av. ± SD, 14.4 (± 6.9) × 7.2 (± 1.9) μm], walls up to 1 μm thick, hila protuberant, 0.8-2(-2.5) μm diam, thickened and darkened-refractive; microcyclic conidiogenesis occurring. Conidia formed by micronematous conidiophores paler and narrower, mostly formed in unbranched chains, sometimes in branched chains with up to three distal hila, straight to slightly curved, limoniform, narrowly fusiform, almost filiform to subcylindrical, 10-26(-35) × 2-3.5 μm [av. ± SD, 15.6 (± 6.2) × 2.9 (± 0.5) μm], 0-1(-3)-septate, subhyaline to pale brown, almost smooth to minutely verruculose, walls unthickened, hila protuberant, 1-1.5 μm diam, thickened and somewhat darkened-refractive.

Cultural characteristics: Colonies on PDA attaining 23 mm diam after 14 d at 25 °C, grey-olivaceous to olivaceous, olivaceous-grey reverse, velvety, margin regular, entire edge, narrow, feathery, aerial mycelium abundantly formed, loose, with age covering large parts of the colony, woolly, growth flat with somewhat elevated colony centre, folded, regular, deep into the agar, with few prominent exudates, sporulation profuse. Colonies on MEA attaining 24 mm diam after 14 d at 25 °C, grey- to greenish olivaceous, olivaceous-grey or iron-grey reverse, velvety to powdery, margin narrow, colourless, entire edge, somewhat feathery, aerial mycelium pale olivaceous-grey, sparse, growth convex, radially furrowed, folded in the colony centre, without prominent exudates, sporulating. Colonies on OA attaining 23 mm diam after 14 d at 25 °C, grey-olivaceous, margin more or less regular, entire edge, colourless, somewhat feathery, aerial mycelium whitish to smoke grey, at first sparse, later more abundantly formed, growth flat, without exudates, sporulation profuse.

Specimen examined: Israel, from hypersaline water of Eilat salterns, 2004, coll. N. Gunde-Cimerman, isol. M. Ota, CBS-H 19858, holotype, isotype HAL 2025 F, culture ex-type CBS 121626 = EXF-1733 = CPC 12052.

Substrate and distribution: Hypersaline water; Israel.

Notes: Cladosporium herbaroides is morphologically similar to C. herbarum but differs in having somewhat longer conidia becoming wider, darker and even more thick-walled with age [at first conidia 3-33 × (2-)3-6(-7) μm, with age (3.5-)5-9(-11) μm wide]. Besides that, the species often produces a second conidial type formed on micronematous conidiophores, giving rise to unbranched conidial chains which are almost filiform, limoniform, narrowly fusiform to subcylindrical, much narrower and paler than the ones formed by macronematous conidiophores, 10-26(-35) × 2-3.5 μm. In C. herbarum, conidia formed by micronematous conidiophores do not occur as frequently as in C. herbaroides, and differ in being often clavate and somewhat wider, up to 4(-5) μm wide. Cladosporium macrocarpum is easily distinguishable by having somewhat wider conidiophores (3-)4-6 μm, with distinctly wider swellings, 5-10 μm wide, and the conidia are usually (3-)5-9(-10) μm wide.

Cladosporium herbarum (Pers.: Fr.) Link, Ges. Naturf. Freunde Berlin Mag. Neuesten Entdeck. Gesammten Naturk. 7: 37. 1816: Fr., Syst. mycol. 3(2): 370. 1832. Figs ​Figs16, 16, ​,17, 17, ​,1818 and ​and1919.

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Fig. 16.

Davidiella tassiana (RO, holotype). Ascus and ascospores. Scale bar = 10 μm. P.W. Crous del.

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Fig. 17.

Cladosporium herbarum (CPC 11600). Macro- and micronematous conidiophores and conidia. Scale bar = 10 μm. K. Schubert del.

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Fig. 18.

Cladosporium herbarum (CPC 11600) and its teleomorph Davidiella tassiana (from the host and CPC 12181). A-B. Macronematous conidiophores. C. Micronematous conidiophore. D. Microcyclic conidiogenesis. E. Conidial chain. F. Ascomata on the leaf. G. Ascomata formed in culture on nettle stems. H-I. Asci on the host. J-K. Ascospores in culture. L. Asci in culture. Scale bars: A, E, H, J-L = 10 μm, F-G, I = 200 μm.

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Fig. 19.

Cladosporium herbarum (CPC 11600). A. Overview of hyphal growth and conidiophore formation of a colony on SNA. Conidiophores are often formed on very wide (approx. 10 μm), septate hyphae that often grow near the agar surface. B. A more detailed view on colony organisation reveals the ornamented conidia. Note the septum near the conidiophore (arrow). C. Detail of spore ornamentation and hila on a secondary ramoconidium (arrow). Ornamentation is visible during early stages of spore formation (arrow). D. Structure of the conidiophore, illustrating the complex morphology of the spore-forming apparatus. In addition, secondary ramoconidia, conidia, and a hilum on the conidium are visible. E. Complex structure of the spore-forming apparatus. F. Details of secondary ramoconidia with complex scar-pattern on the right cell. G. Details of a secondary ramoconidium giving rise to conidia. Note the lack of ornamentation at the location of spore formation. Scale bars: A = 50 μm, B, F = 10 μm, C-E, G = 5 μm.

Basionym: Dematium herbarum Pers., Ann. Bot. (Usteri) 11: 32. 1794: Fr., Syst. mycol. 3(2): 370. 1832.

• = Dematium epiphyllum var. (β) chionanthi Pers., Mycol. eur. 1: 16. 1822, syn. nov.

For additional synonyms see Dugan et al. (2004), Schubert (2005).

Teleomorph: Davidiella tassiana (De Not.) Crous & U. Braun, Mycol. Progr. 2: 8. 2003.

Basionym: Sphaerella tassiana De Not., Sferiacei Italici 1: 87. 1863.

• ≡ Mycosphaerella tassiana (De Not.) Johanson, Öfvers. Förh. Kongl. Svenska Vetensk.-Akad. 41: 167. 1884.

Ascomata pseudothecial, black, globose, erumpent to superficial, up to 200 μm diam, with 1(-3) short, periphysate ostiolar necks; wall consisting of 3-6 layers of medium red-brown textura angularis. Asci fasciculate, bitunicate, subsessile, obovoid to broadly ellipsoid, straight to slightly curved, 8-spored, 65-85 × 13-17 μm. Pseudoparaphyses absent in host material, but remnants observed when studied in culture, hyaline, septate, subcylindrical, anastomosing, 3-4 μm wide. Ascospores tri- to multiseriate, overlapping, hyaline, with irregular luminar inclusions, thick-walled, straight to slightly curved, fusoid-ellipsoidal with obtuse ends, widest near middle of apical cell, medianly 1-septate, not to slightly constricted at the septum, tapering towards both ends, but more prominently towards the lower end, (17-)20-23(-25) × (6-)7(-8) μm; becoming brown and verruculose in asci. Ascospores germinating after 24 h on MEA from both ends, with spore body becoming prominently constricted at the septum, but not distorting, up to 7 μm wide, hyaline to pale brown and appearing somewhat verruculose, enclosed in a mucoid sheath, with germ tubes being irregular, somewhat nodular.

Mycelium superficial, loosely branched, (0.5-)1-5 μm wide, septate, sometimes constricted at septa, hyaline, subhyaline to pale brown, smooth or almost so to verruculose or irregularly rough-walled, sometimes appearing irregular in outline due to small swellings and constrictions, walls unthickened to somewhat thickened, cell lumen appearing to be granular. Conidiophores both macro- and micronematous, arising laterally from plagiotropous hyphae or terminally from ascending hyphae. Macronematous conidiophores erect, straight to flexuous, somewhat geniculate-sinuous, nodulose to nodose with unilateral or multilateral swellings, with a single to numerous swellings in short succession giving the stalk a knotty/gnarled appearance, unbranched or occasionally branched, up to three times, sometimes with a lateral branch-like proliferation below or at the apex, 10-320 × 3.5-5 μm, swellings 5-8(-9) μm wide, pluriseptate, septa sometimes constricted when formed after a node, pale to medium brown, older ones almost dark brown, paler towards the apex, smooth or minutely verruculose, walls thickened, sometimes even two-layered. Conidiogenous cells integrated, terminal or intercalary, nodulose to nodose, with a single or up to five swellings per cell, 10-24 μm long, proliferation sympodial, with several conidiogenous loci confined to swellings, mostly situated on small lateral shoulders, more or less protuberant, broadly truncate to slightly convex, 1.5-2.5 μm diam, thickened and somewhat darkened-refractive. Micronematous conidiophores hardly distinguishable from hyphae, sometimes only as short lateral outgrowth with a single apical scar, short, conical to almost filiform or narrowly cylindrical, non-nodulose, not geniculate, unbranched, 5-120 × 1.5-3(-4) μm, pluriseptate, not constricted at septa, cells usually very short, 5-15 μm long, subhyaline to pale brown, almost smooth to minutely verruculose or irregularly rough-walled, sometimes forming clavate conidia, up to 33 μm long, 0-2-septate. Conidiogenous cells integrated, terminal or conidiophores reduced to conidiogenous cells, narrowly cylindrical or filiform, with a single or two loci. Conidia catenate, in unbranched or loosely branched chains with branching mostly occurring in the lower part of the chain, straight to slightly curved, small terminal conidia without distal hilum obovoid, 4-10 × 3-5(-6) μm [av. ± SD, 7.8 (± 1.9) × 4.7 (± 0.9) μm], aseptate, intercalary conidia with a single or sometimes up to three distal hila limoniform, ellipsoid to subcylindrical, 6-16 × 4-6 μm [av. ± SD, 12.4 (± 1.6) × 5.3 (± 0.6) μm], 0-1-septate, secondary ramoconidia with up to four distal hila, ellipsoid to cylindrical-oblong, 12-25(-35) × (3-)5-7(-9) μm [av. ± SD, 18.8 (± 4.5) × 6.2 (± 0.9) μm], 0-1(-2)-septate, rarely with up to three septa, sometimes distinctly constricted at the septum, septum median or somewhat in the upper or lower half, pale greyish brown or brown to medium brown or greyish brown, minutely verruculose to verrucose, walls slightly to distinctly thickened, guttulate to somewhat granular, usually only slightly attenuated towards apex and base, apex obtuse or slightly truncate, towards the base sometimes distinctly attenuated with hila situated on short stalk-like prolongations, hila slightly to distinctly protuberant, truncate to slightly convex, (0.8-)1-2.5(-3) μm wide, 0.5-1 μm high, somewhat thickened and darkened-refractive; microcyclic conidiogenesis occurring, conidia forming micro- and macronematous secondary conidiophores.

Cultural characteristics: Colonies on PDA reaching 19-37 mm diam after 14 d at 25 °C, grey-olivaceous to olivaceous-grey, whitish to smoke-grey or pale olivaceous-grey due to abundant aerial mycelium, velvety, reverse olivaceous-grey or iron-grey, margin almost colourless, regular, entire edge, glabrous to feathery, aerial mycelium abundant mainly in the colony centre, dense, felty, woolly, sometimes becoming somewhat reddish brown, fawn coloured, growth regular, flat to low convex with an elevated colony centre, sometimes forming few large prominent exudates, sporulation profuse. Colonies on MEA reaching 17-37 mm diam after 14 d at 25 °C, smoke-grey to pale olivaceous-grey towards margin, olivaceous-grey to iron-grey reverse, velvety, margin white, entire edge to slightly undulate, aerial mycelium abundant, dense, fluffy to felty, growth low convex or raised, radially furrowed, folded and wrinkled in the colony centre, without prominent exudates but sporulating. Colonies on OA reaching 12-28 mm diam after 14 d at 25 °C, olivaceous-grey to iron-grey, due to abundant aerial mycelium pale olivaceous-grey, olivaceous-grey reverse, margin narrow, more or less undulate, white, aerial mycelium white, loose to dense, high, fluffy to felty, covering large parts of the colony, growth flat to low convex, without prominent exudates, sporulating.

Specimens examined: Sine loco, Sine dato, L 910.225-733, lectotype of C. herbarum, selected by Prasil & de Hoog, 1988. Sine loco, on leaves of Chionanthus sp. (Oleaceae), L 910.255-872 = L-0115833, holotype of Dematium epiphyllum var. (β) chionanthi. Netherlands, Wageningen, isolated from Hordeum vulgare (Poaceae), 2005, P.W. Crous, CBS-H 19853, epitype designated here of C. herbarum and D. tassiana, isoepitype HAL 2022 F, ex-type cultures, CPC 12177 = CBS 121621, CPC 12178-12179, 12181, 12183. Italy, on upper and lower surface of dead leaves of Carex nigra [“fusca”] (Cyperaceae), Tassi no. 862, RO, holotype of Davidiella tassiana. U.S.A., Colorado, San Juan Co., above Little Molas Lake, isolated from stems of Delphinium barbeyi (Ranunculaceae), 12 Sep. 2004, A. Ramaley, CBS-H 19868 (teleomorph), single ascospore isolates, CBS 121622 = CPC 11600, CPC 11601-11604.

Substrate and distribution: On fading and decaying plant material, on living leaves (phylloplane fungus), as secondary invader, as an endophyte, isolated from air, soil, foodstuffs, paints, textiles and numerous other materials; cosmopolitan.

Literature: de Vries (1952: 71), Hughes (1958: 750), Ellis (1971: 313), Domsch et al. (1980: 204), Sivanesan (1984: 225), Ellis & Ellis (1985: 290, 468, 1988: 168), Prasil & de Hoog (1988), Wang & Zabel (1990: 202), McKemy & Morgan-Jones (1991), Dugan & Roberts (1994), David (1997: 59), Ho et al. (1999: 129), de Hoog et al. (2000: 587), Samson et al. (2000: 110), Samson et al. (2001).

Notes: De Vries (1952) incorrectly selected a specimen of Link's herbarium at herb. B as lectotype. Prasil & de Hoog (1988) discussed this typification and designated one of Persoon's original specimens as lectotype in which C. herbarum could be recognised. The latter material, which is in poor condition, could be re-examined within the course of these investigations and showed conidia agreeing with the current species concept of C. herbarum being (6-)9.5-14.5(-21) × (5-)6-7(-8) μm. Since the identity of the strain CBS 177.71 chosen by Prasil & de Hoog (1988) as representative living strain of C. herbarum could not be corroborated, an epitype with a living ex-epitype culture is designated. The holotype specimen of D. tassiana (RO) is morphologically similar to that observed on the epitype of C. herbarum, having ascospores which are (17-)21-23(-25) × (6-)7-8(-8.5) μm, turning brown and verruculose in asci with age. However, no hamathecial remnants were observed in ascomata in vivo.

The connection to the teleomorph D. tassiana could be confirmed, which is in agreement with the findings of von Arx (1950) and Barr (1958). Ascospore isolates formed the typical C. herbarum anamorph in culture, and these anamorph cultures developed some immature fruiting bodies within the agar. When inoculated onto water agar plates with nettle stems, numerous ascomata with viable ascospores were formed in culture.

Cladosporium iridis (Fautrey & Roum.) G.A. de Vries, Contr. Knowl. Genus Cladosporium: 49. 1952. Figs ​Figs2020-​-2121.

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Fig. 20.

Cladosporium iridis (CBS 138.40). Conidiophores and conidia. Scale bar = 10 μm. K. Schubert del.

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Fig. 21.

Cladosporium iridis (teleomorph Davidiella macrospora) (CBS 138.40). A-C. Conidiophores with conidia. D. Conidium. Scale bar = 10 μm.

Basionym: Scolicotrichum iridis Fautrey & Roum., Rev. Mycol. (Toulouse) 13: 82. 1891.

• ≡ Heterosporium iridis (Fautrey & Roum.) J.E. Jacques, Contr. Inst. Bot. Univ. Montréal 39: 18. 1941.

For additional synonyms see Dugan et al. (2004).

Teleomorph: Davidiella macrospora (Kleb.) Crous & U. Braun, Mycol. Progr. 2: 10. 2003.

Basionym: Didymellina macrospora Kleb., Ber. Deutsch. Bot. Ges. 42: 60, 1924. 1925.

• ≡ Mycosphaerella macrospora (Kleb.) Jørst., Meld. Stat. Plantepatol. Inst. 1: 20. 1945.

Mycelium branched, 2-8 μm wide, septate, not constricted at the septa, hyaline to pale brown, smooth, walls slightly thickened, sometimes guttulate. Conidiophores very long, usually terminally arising from ascending hyphae, erect to subdecumbent, slightly to distinctly flexuous, geniculate-sinuous, usually several times, subnodulose due to geniculate, sympodial proliferation forming swollen lateral shoulders, unbranched, rarely branched, up to 720 μm long, 6-11 μm wide, swellings 8-11(-14) μm wide, pluriseptate, often very regularly septate, not constricted at the septa, pale to medium olivaceous-brown, somewhat paler towards the apex, smooth to minutely verruculose, walls only slightly thickened. Conidiogenous cells integrated, terminal as well as intercalary, cylindrical-oblong, 15-55 μm long, proliferation percurrent to sympodial, usually with a single geniculation forming laterally swollen shoulders often below a septum, conidiogenous loci confined to swellings, usually one locus per swelling, rarely two, protuberant, (2-)2.5-4 μm diam, somewhat thickened and darkened-refractive. Conidia solitary, sometimes in short, unbranched chains, straight to curved, young conidia pyriform to subcylindrical, connection between conidiophore and conidium being rather broad, subhyaline to pale olivaceous-brown, walls slightly thickened, then enlarging and becoming more thick-walled, cylindrical-oblong, soleiform with age, both ends rounded, usually with a slightly to distinctly bulbous base, visible from a very early stage, but broadest part often towards the apex not at the base, (18-)30-75(-87) × (7-)10-16(-18) μm [av. ± SD, 53.3 (± 17.8) × 12.6 (± 2.2) μm], (0-)2-6(-7)-septate, usually not constricted at the septa, rarely slightly constricted, septa often becoming sinuous with age, pale to medium olivaceous-brown, sometimes darker, verrucose to echinulate, walls thickened, especially in older conidia, up to 1 μm thick, hila protuberant, often stalk-like or conically prolonged, up to 2 μm long, (2-)2.5-3.5(-4) μm diam, with age becoming more sessile, sometimes just visible as a thickened plate just below the outer wall layer, especially in distal scars of branched conidia, periclinal rim often distinctly visible, hila somewhat thickened and darkened-refractive; microcyclic conidiogenesis not observed.

Cultural characteristics: Colonies on PDA reaching 19-23 mm diam after 14 d at 25 °C, pale greenish olivaceous, smoke-grey to olivaceous-grey due to abundant aerial mycelium, greenish olivaceous to olivaceous reverse, margin broad, regular, entire edge to slightly undulate, feathery, aerial mycelium abundantly formed, felty, fluffy, covering large parts of the colony, mainly in the central parts, high, growth low convex with a somewhat raised colony centre. Colonies on MEA reaching 9-23 mm diam after 14 d at 25 °C, pale olivaceous-grey to olivaceous-grey, olivaceous-grey reverse, felty, margin slightly undulate, white, somewhat raised, aerial mycelium abundant, loose, diffuse, high, growth low convex, radially furrowed, slightly folded. Colonies on OA reaching 10-19 mm diam after 14 d at 25 °C, olivaceous, margin broad, undulate, white, aerial mycelium white, very high, loose, diffuse, hairy, growth flat, due to the mycelium low convex, without prominent exudates and sporulating on all media.

Specimens examined: Isolated from Iris sp. (Iridaceae), CBS 107.20. France, Cote d'Or, Jardin de Noidan, on leaves of Iris germanica, Jul. 1880, F. Fautrey, Roumeguère, Fungi Sel. Gall. Exs. No. 5689, PC, lectotype of C. iridis, selected by David, 1997; K, isolectotype. Netherlands, Boterenbrood, isolated from leaves of Iris sp., Aug. 1940, CBS-H 19859, epitype designated here of C. iridis, culture ex-epitype CBS 138.40.

Substrates and distribution: Leaf spot and blotch of Iris spp. including I. crocea, I. florentina, I. foetidissima, I. germanica, I. gueldenstaedtiana, I. kamaonensis, I. pallida, I. plicata (= I. swertii Hort.), I. pseudacorus, I. pumila, I. spuria ssp. halophila, and other species, also on Belacamanda chinensis (= Gemmingia chinensis), Hemerocallis fulva, Gladiolus gandavensis; Africa (Algeria, Morocco, South Africa, Zambia, Zimbabwe), Asia (Armenia, Azerbaijan, China, Georgia, India, Iran, Israel, Japan, Kazakhstan, Kirgizstan, Korea, Russia, Turkey, Turkmenistan, Uzbekistan), Australasia (Australia, New Zealand), Europe (Austria, Belgium, Belorussia, Cyprus, Czech Republic, Denmark, Estonia, France, Germany, Great Britain, Greece, Italy, Latvia, Lithuania, Malta, Moldavia, Montenegro, Netherlands, Norway, Poland, Romania, Russia, Serbia, Spain, Sweden, Ukraine), North America (Canada, U.S.A.), Central & South America (Argentina, Chile, Jamaica, Panama, Uruguay).

Literature: Ellis (1971: 312), Ellis & Waller (1974), Sivanesan (1984: 222), McKemy & Morgan-Jones (1990), David (1997: 43), Shin et al. (1999).

Notes: The description of the morphological parameters in culture is based on the isolate sporulating on PDA, since sporulation on SNA was not observed. The conidiophores and conidia in vivo are usually wider than in culture [conidiophores (6-)9-15(-17) μm wide, conidia (11-)15-23(-28) μm].

Cladosporium macrocarpum Preuss, in Sturm, Deutsch. Fl. 3(26): 27. 1848. Figs ​Figs22, 22, ​,23, 23, ​,2424 and ​and2525.

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Fig. 22.

Cladosporium macrocarpum (CBS 299.67). Macro- and micronematous conidiophores and conidia. Scale bar = 10 μm. K. Schubert del.

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Fig. 23.

Cladosporium macrocarpum (CBS 299.67) and its teleomorph Davidiella macrocarpa (CPC 12755). A-C. Macronematous conidiophores and conidia. D-G. Micronematous conidiophores. H. Microcyclic conidiogenesis. I. Ascomata formed on nettle stems in culture. J. Periphyses. K, M-N. Asci. L. Ostiole. Scale bars: A, D-H, J-N = 10 μm, I = 200 μm.

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Fig. 24.

Cladosporium macrocarpum (CBS 299.67). A. Survey of a conidiophore that forms several secondary ramoconidia and conidia. Several aerial hyphae are also visible in this picture. B. Conidiophore with broadly ellipsoid secondary ramoconidia and obovoid conidia. Note the different scars on the conidiophore at the lower left. C. Ellipsoid or obovoid conidia with notable areas of scar formation. The ornamentation is relatively widely distributed over the body of the cell and similar to C. variabile. D. Detail of a conidiophore (see B) with scars. Note the relatively shallow rings of the scars. E. Details of conidia and a secondary ramoconidium. F. Conidiophore with a secondary ramoconidium and conidia. Note the hila on several spores and the lack of ornamentation at the site where spores are formed. Scale bars: A-C, = 10 μm, D, F = 5 μm, E = 2 μm.

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Fig. 25.

Davidiella macrocarpa (CPC 12755). Ascus and ascospores. Scale bar = 10 μm. P.W. Crous del.

• ≡ Cladosporium herbarum var. macrocarpum (Preuss) M.H.M. Ho & Dugan, in Ho et al., Mycotaxon 72: 131. 1999.

  • = Dematium herbarum var. (β) brassicae Pers., Syn. meth. fung. 2: 699. 1801, syn. nov.

  • = Dematium graminum Pers., Mycol. eur. 1: 16. 1822, syn. nov.

  • = Dematium vulgare var. (δ) typharum Pers., Mycol. eur. 1: 14. 1822, syn. nov.

  • = Dematium vulgare var. (β) foliorum Pers., Mycol. eur. 1: 14. 1822, syn. nov.

For additional synonyms see Dugan et al. (2004), Schubert (2005).

Teleomorph: Davidiella macrocarpa Crous, K. Schub. & U. Braun, sp. nov. MycoBank MB504582.

Davidiellae tassianae similis, sed pseudoparaphysibus prominentibus et ascosporis maioribus, (22-)23-26(-28) × (6-)6.5-7(-8) μm.

Ascomata superficial on a small stroma, black, up to 200 μm diam, globose, separate, but developing with 1-3 necks with age; ostioles consisting of pale brown to subhyaline cells, periphysate, with periphysoids growing into the cavity; wall consisting of 3-6 layers of medium brown textura angularis. Pseudoparaphyses present, hyaline, subcylindrical, septate, anastomosing, 3-4 μm diam; hamathecial cells persistent in cavity. Asci fasciculate, bitunicate, subsessile, broadly ellipsoid with a long tapered stalk, straight to curved, 8-spored, 70-110 × 15-20 μm. Ascospores tri- to multiseriate, overlapping, hyaline, guttulate, irregular lumina rarely observed, thick-walled, straight to slightly curved, fusoid-ellipsoidal with obtuse ends, widest in the middle of the apical cell, medianly 1-septate, not to slightly constricted at the septum, tapering towards both ends, but more prominently towards lower end, (22-)23-26(-28) × (6-)6.5-7(-8) μm; mucoid sheath rarely observed, mostly absent.

Mycelium unbranched or loosely branched, 1-4.5(-5) μm wide, septate, sometimes slightly constricted at septa, hyaline to pale brown, smooth to minutely verruculose, walls unthickened or slightly thickened. Conidiophores micronematous and macronematous, solitary, arising terminally from plagiotropous hyphae or terminally from ascending hyphae. Macronematous conidiophores erect, straight to somewhat flexuous, cylindrical-oblong, nodulose to nodose, with a single apical or usually several swellings either somewhat distinct from each other or often in short succession giving conidiophores a knotty appearance, swellings sometimes laterally elongated or formed at the top of a branch-like outgrowth below the apical swelling, sometimes distinctly geniculate, unbranched, sometimes branched, 12-260 × (3-)4-6 μm, swellings 5-10 μm wide, pluriseptate, sometimes slightly constricted at septa, pale to medium brown or olivaceous-brown, somewhat paler at apices, smooth to minutely verruculose or verruculose, walls somewhat thickened, sometimes even two-layered. Conidiogenous cells integrated, terminal or intercalary, cylindrical, nodulose with lateral shoulders or nodose with swellings round about the stalk, with conidiogenous loci confined to swellings, 12-37 μm long, with up to 12 loci per cell, usually with up to six, loci conspicuous, protuberant, (1-)1.5-2 μm diam, somewhat thickened and darkened-refractive. Micronematous conidiophores almost indistinguishable from hyphae, straight, narrowly filiform, non-nodulose or with a single or few swellings, mostly with small head-like swollen apices, usually only few micrometer long, 1.5-3 μm wide, aseptate or with only few septa, subhyaline, smooth or almost so, walls unthickened, with a single or only few conidiogenous loci, narrow, 0.8-1.2 μm diam, thickened and somewhat darkened-refractive. Conidia catenate, in branched chains, small terminal conidia subglobose, obovoid, oval, limoniform, 4-11 × (3-)4-6 μm [av. ± SD, 7.6 (± 1.9) × 5.0 (± 0.8) μm], aseptate, intercalary conidia broadly ovoid-ellipsoid, 10-17 × (4.5-)5-9 μm [av. ± SD, 12.7 (± 2.1) × 6.8 (± 0.8) μm], 0-1-septate; secondary ramoconidia broadly ellipsoid to subcylindrical, 14-25(-30) × (5-)6-9(-10) μm [av. ± SD, 19.4 (± 3.5) × 7.6 (± 1.0) μm], 0-2(-3)-septate, sometimes slightly constricted at the septa, septa somewhat sinuous with age, pale brown to medium olivaceous-brown or brown, sometimes even dark brown, verruculose to echinulate (muricate under SEM), walls thickened, up to 1 μm thick, mostly broadly rounded at apex and base, sometimes attenuated, sometimes guttulate by oil drops, with up to three apical hila, mostly 1-2, hila sessile (apparently somewhat immersed) to somewhat protuberant, 1-2(-2.5) μm diam, thickened and darkened-refractive; microcyclic conidiogenesis occurring with conidia forming secondary micro- and macronematous conidiophores, conidia often germinating with long hyphae. Conidia formed by micronematous conidiophores usually smaller, narrower and paler, catenate, in short unbranched or branched chains, subglobose, obovoid to limoniform, ellipsoid or fusiform, 2.5-16 × 1.5-5 μm, 0(-1)-septate, few longer conidia subcylindrical to clavate, up to 37(-43) μm long, 0-2(-3)-septate, occasionally with up to four septa, sometimes slightly constricted at the septa, subhyaline to pale brown, almost smooth to minutely verruculose, walls unthickened, hila 0.8-1.2 μm diam, thickened and darkened-refractive.

Cultural characteristics: Colonies on PDA reaching 30-43 mm in diam after 14 d at 25 °C, dark dull green to olivaceous-grey, olivaceous-grey, dark olivaceous- to iron-grey reverse, pulvinate, velvety, sometimes somewhat zonate, paler zones towards the margin, margin regular, entire edge, almost colourless to white, glabrous to feathery, aerial mycelium sparse to more abundant in the colony centre or covering large areas of the colony, hairy, fluffy or felty, whitish to smoke-grey, sometimes becoming reddish, livid red to vinaceous, growth flat, regular, sometimes forming few prominent exudates, exudates sometimes slightly reddish, sporulation profuse with two kinds of conidiophores, low and high. Colonies on MEA reaching 31-50 mm in diam after 14 d at 25 °C, grey-olivaceous to olivaceous-grey or iron-grey, sometimes pale olivaceous-grey to whitish due to abundant aerial mycelium, olivaceous-grey or iron-grey reverse, velvety or powdery, margin narrow, entire edge, colourless to white, glabrous, aerial mycelium sparse to abundant, hairy or felty, growth regular, flat to low convex, radially furrowed, without prominent exudates, sporulation profuse. Colonies on OA reaching 29-40 mm in diam after 14 d at 25 °C, grey-olivaceous, olivaceous-grey to dark smoke-grey, olivaceous-black or iron grey reverse, margin entire edge, narrow, colourless or white, glabrous, aerial mycelium sparse, mainly in the colony centre, felty, white to smoke-grey or grey-olivaceous, felty, growth flat, regular, without exudates, sporulating.

Specimens examined: Sine loco et dato, L 910.255-723 = L-0115836, lectotype designated here of Dematium graminum. Sine loco, on dead stems of Brassica sp. (Brassicaceae), No. 601, L 910.255-716 = L-0115849, holotype of D. herbarum var. (β) brassicae. Sine loco, on leaves of Iris (Iridaceae), Quercus (Fagaceae), Brassica etc., L 910.255-736 = L-0115871, holotype of D. vulgare var. (β) foliorum, isotype L 910.255-718 = L-0115872. Sine loco et dato, L 910.255-698 = L-0115852, lectotype designated here for D. vulgare var. (δ) typharum. Isolated from “Mycosphaerella tulasnei”, CBS 223.32 = ATCC 11287 = IMI 049635. Romania, isolated from water, CBS 175.82. Slovenia, Sečovlje, isolated from hypersaline water from salterns (precrystalisation pond), 2004, P. Zalar, EXF-2287 = CPC 12054. Turkey, Ankara, Tekeli, isolated from Triticum aestivum (Poaceae), isol. S. Tahsin, ident. A.C. Stolk, CBS 299.67. U.S.A., Seattle, University of Washington Campus, 47.6263530, - 122.3331440, isolated from cleistothecia of Phyllactinia guttata (Erysiphaceae) on leaves of Corylus sp. (Corylaceae), 16 Sep. 2004, D. Glawe, CPC 11817; Washington, isolated from Spinacia oleracea (Chenopodiaceae), 1 Jan. 2003, L. DuToit, CBS-H 19855, neotype designated here for C. macrocarpum, and holotype of D. macrocarpa, isoneotype HAL 2020 F, isotype HAL 2021 F, culture ex-type CPC 12752, 12756-12759, CPC 12755 = CBS 121623.

Substrate and distribution: Decaying plant material, human, hypersaline water, water; widespread.

Literature: de Vries (1952: 76), Ellis (1971: 315), Domsch et al. (1980: 208), Ellis & Ellis (1985: 290, 468), Matsushima (1985: 5), McKemy & Morgan-Jones (1991), Dugan & Roberts (1994), David (1997: 71), Samson et al. (2000: 112).

Notes: In the absence of Preuss's type material (not preserved) de Vries (1952) “lectotypified” C. macrocarpum by a specimen in Saccardo's herbarum (Herb. Myc. P.A. Saccardo no. 419, PAD). This material, subsequently distributed in Mycotheca Italica no. 1396, should correctly be regarded as neotype (David 1997). A single collection of Saccardo's Mycotheca Italica no. 1396 from herb. HBG, which can be considered as isoneotype material, was re-examined and proved to rather agree with the species concept of C. herbarum s. str. The conidia were formed in simple, rarely branched chains, 6-26 × (4-)5.5-8(-9) μm, 0-3-septate, almost smooth or minutely to densely verruculose or verrucose (Schubert 2005). However, since de Vries' “lectotypification” was incorrect according to the code (ICBN, Art. 9.2, 9.17), a neotype is designated.

The delimitation of C. macrocarpum as a morphologically distinct species from C. herbarum has been controversially discussed by several authors (McKemy & Morgan-Jones 1991, Dugan & Robert 1994, Ho et al. 1999). Based on molecular as well morphological studies, it can be shown that C. macrocarpum is a well-defined species distinguishable from C. herbarum s. str. by forming conidiophores with wider nodes, 5-10 μm, wider and more frequently septate conidia [small terminal conidia 4-11 × (3-)4-6 μm versus 4-10 × 3-5(-6) μm in C. herbarum, intercalary conidia 10-17 × (4.5-)5-9 μm versus 6-16 × 4-6 μm in C. herbarum, secondary ramoconidia 14-25(-30) × (5-)6-9(-10) μm versus 12-25(-35) × (3-)5-7(-9) μm in C. herbarum] and by being connected to Davidiella macrocarpa. On natural substrates the conidiophores are usually somewhat wider than in culture, 4-8(-10) μm wide, and also the conidia can be somewhat wider, sometimes up to 13(-15) μm.

Cladosporium graminum, described by Persoon (1822), as well as C. brunneum and C. gracile, introduced by Corda (1837), are older synonyms of C. macrocarpum and, according to the code, would have priority. However, since C. macrocarpum is a well established, currently used name with numerous records in literature, a proposal to conserve the name against these older names is in preparation for formal publication in Taxon.

A characteristic difference between ascomata of C. macrocarpum in comparison to those of C. herbarum, are the smaller, globose pseudothecia, asci with longer stalks, prominence of pseudoparaphyses, and rather inconspicuous luminar ascospore inclusions.

Cladosporium ossifragi (Rostr.) U. Braun & K. Schub., comb. nov. MycoBank MB504575. Figs ​Figs26, 26, ​,2727 and ​and2828.

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Fig. 26.

Cladosporium ossifragi (CBS 842.91). Conidiophores and conidia. Scale bar = 10 μm. K. Schubert del.

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Fig. 27.

Cladosporium ossifragi (CBS 842.91). A. Macronematous conidiophore. B. Micronematous conidiophore. C-D. Conidia. E. Conidia and microcyclic conidiogenesis. Scale bars = 10 μm.

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Fig. 28.

Cladosporium ossifragi (CBS 842.91). A. Survey on different secondary ramoconidia and conidia. B. Details of conidia and hila. Note the very pronounced ornamentation and the absence of ornamentation near the site of spore formation. C. Detail of the end of a secondary ramoconidium with pronounced hila. D. Formation of a new conidium. Note the broad scar behind it (> 1 μm). E. Formation of a new conidium from a smooth-walled stalk. F. Hila on a secondary ramoconidium. This micrograph is from the sample before coating with gold-palladium and shows similar features as the sample after sputter coating. Scale bars: A = 10 μm, B-D, F = 2 μm, E = 5 μm.

Basionym: Napicladium ossifragi Rostr., Bot. Fǽröes 1: 316. 1901.

• ≡ Heterosporium ossifragi (Rostr.) Lind, Dan. fung.: 531. 1913.

  • = Heterosporium magnusianum Jaap, Schriften Naturwiss. Vereins Schleswig-Holstein 12: 346. 1902.

• ≡ Cladosporium magnusianum (Jaap) M.B. Ellis in Ellis, More Dematiaceous Hyphomycetes: 337. 1976.

Mycelium abundantly formed, twisted, often somewhat aggregated, forming ropes, branched, 1-5 μm wide, septate, often irregularly swollen and constricted, hyaline or subhyaline to pale brown, smooth, walls unthickened or only slightly thickened. Conidiophores macronematous and micronematous, arising from plagiotropous hyphae, terminally or laterally, erect to subdecumbent, more or less straight to flexuous, cylindrical, sometimes geniculate, subnodulose with loci often situated on small lateral shoulders, unbranched, sometimes branched, often very long, up to 350 μm long, 3-4.5(-5) μm wide, pluriseptate, shorter ones aseptate, not constricted at septa, pale to pale medium brown, paler towards apices, sometimes subhyaline, smooth to minutely verruculose, especially towards apices, walls somewhat thickened, up to 0.5 μm, sometimes appearing two-layered. Conidiogenous cells integrated, terminal as well as intercalary, cylindrical, sometimes geniculate, subnodulose, 5-31 μm long, proliferation sympodial, with few loci (1-3) per cell, loci usually confined to small lateral shoulders, protuberant, conspicuous, short cylindrical, 1-2 μm wide, up to 1 μm high, somewhat thickened, darkened-refractive. Conidia catenate, in short, unbranched or branched chains, straight, small terminal and intercalary conidia subglobose, obovoid to ellipsoid, 4-15 × 3-5 μm [av. ± SD, 9.3 (± 3.7) × 4.0 (± 0.7) μm], 0-1-septate, not constricted at the septa, pale brown, hila 0.8-1 μm diam, secondary ramoconidia cylindrical, sometimes ellipsoid or subfusiform, 16-36(-40) × (4-)5-8 μm [av. ± SD, 26.6 (± 7.4) × 6.0 (± 1.2) μm], (0-)1-3(-4)-septate [in vivo wider, (6-)7-9(-11) μm, and with up to five, rarely seven septa], not constricted at the septa, septa sometimes slightly sinuous, pale brown to pale medium brown, densely verruculose, verrucose to echinulate (densely muricate under SEM), walls unthickened to somewhat thickened, rounded or somewhat attenuated at apex and base, hila protuberant, conspicuous, sometimes situated on short, small prolongations, 1-2.5 μm diam, somewhat thickened and darkened-refractive; microcyclic conidiogenesis occasionally occurring.

Cultural characteristics: Colonies on PDA reaching 53 mm diam after 14 d at 25 °C, greenish olivaceous, grey-olivaceous to olivaceous-grey or iron-grey, appearing somewhat zonate, dull green to olivaceous-black reverse, margin colourless, regular, entire edge, aerial mycelium abundantly formed, covering at first the colony centre later most of the surface, dense, high, growth flat with elevated colony centre, somewhat folded. Colonies on MEA reaching 54 mm diam after 14 d at 25 °C, pale olivaceous-grey to olivaceous-grey in the centre, iron-grey reverse, velvety, margin colourless to white, entire edge, radially furrowed, aerial mycelium abundantly formed, fluffy to felty, growth flat with somewhat raised, folded colony centre. Colonies on OA attaining 52 mm diam after 14 d at 25 °C, olivaceous-grey to iron-grey, iron-grey to greenish black reverse, margin white, entire edge, aerial mycelium diffuse, loose, growth flat, prominent exudates absent, sporulation profuse on all media.

Specimens examined: Denmark, Undallslund, on leaves of Narthecium ossifragum (Melanthiaceae), 13 Sep. 1885, E. Rostrup, CP, neotype designated here of C. ossifragi; Tǿnder, Rǿmǿ near Twismark, 19 Aug. 1911, H. Sydow, Sydow, Mycoth. Germ. 1047, M. Germany, Hamburg, Eppendorfer Moor, on leaves of Narthecium ossifragum, 12 Sep. 1897, O. Jaap, HBG, lectotype selected here of C. magnusianum; 4 Sep. 1903, O. Jaap, Jaap, Fungi Sel. Exs. 49, M; Wernerwald near Cuxhaven, Aug. 1927, A. Ludwig, Petrak, Mycoth. Gen. 146, M. Norway, Bjerkreim County, isolated from leaves of Narthecium ossifragum, M. di Menna, CBS-H 19860, epitype designated here of C. ossifragi, culture ex-epitype CBS 842.91 = ATCC 200946; Møre og Romsdal County, isolated from leaves of Narthecium ossifragum, M. di Menna, CBS 843.91.

Substrate and distribution: Causing leaf spots on Narthecium ossifragum; Europe (Austria, Denmark, Germany, Great Britain, Ireland, Norway).

Literature: Ellis & Ellis (1985: 390), David (1995a; 1997: 85-86, 88), Ho et al. (1999: 132).

Notes: Type material of Napicladium ossifragi is not preserved in Rostrup's herbarium (on Narthecium ossifragum, Faeroe Islands, Viderö, Viderejde and Österö, Svinaa, sine dato, leg. Ostenfeld & Harz). However, other authentic collections seen and examined by Rostrup are deposited at CP. Lind (1913) re-examined these samples, synonymised N. ossifragi with H. magnusianum and correctly introduced the combination H. ossifragi. Nevertheless, the correct oldest name for this fungus has been ignored by most authors. David (1997), who clearly stated that N. ossifragi is the earliest name for this species, preferred to use the name C. magnusianum because the typification of Rostrup's name was still uncertain. Despite the lacking type material, there is no doubt about the correct identity of N. ossifragi since authentic material of this species, examined by and deposited in Rostrup's herbarium (CP), is preserved. Therefore, there is no reason to reject the oldest valid name for this species. The original collection of C. magnusianum cited by Jaap (1902) (on leaves of Narthecium ossifragum, Denmark, Tǿnder, Rǿmǿ, peatbog by Twismark, Jul.-Aug. 1901, Jaap), but not designated as type, is not preserved (David 1997). It is neither deposited at B, HBG nor S. However, in the protologue Jaap (1902) also referred to material of this species found near Hamburg, which is, hence, syntype material available for lectotypification.

Cladosporium pseudiridis K. Schub., C.F. Hill, Crous & U. Braun, sp. nov. MycoBank MB504576. Figs ​Figs2929-​-3030.

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Fig. 29.

Cladosporium pseudiridis (CBS 116463). Conidiophores and conidia. Scale bar = 10 μm. K. Schubert del.

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Fig. 30.

Cladosporium pseudiridis (CBS 116463). A-C. Conidiophores and conidia. D. Part of a conidiogenous cell showing a protuberant cladosporioid conidiogenous locus. E-F. Conidia. Scale bars = 10 μm.

Etymology: Epithet derived from its similar morphology to Cladosporium iridis.

Differt a Cladosporio iridis conidiis 0-3-septatis, brevioribus et latioribus, 15-55 × (9-)11-19(-21) μm.

Mycelium sparingly branched, 2-7 μm wide, septate, not constricted at the septa, subhyaline to pale brown, smooth or almost so, walls somewhat thickened, guttulate or protoplasm appearing granular, sometimes enveloped by a slime coat. Conidiophores arising mostly terminally from ascending hyphae, sometimes also laterally from plagiotropous hyphae, erect, more or less straight, broadly cylindrical-oblong, once or several times slightly to distinctly geniculate-sinuous, forming more or less pronounced lateral shoulders, nodulose, unbranched, 100-320(-500) × 7-11 μm, swellings 10-14 μm wide, becoming narrower and paler towards the apex, septate, not constricted at the septa, septa mainly basal, apical cell often very long, pale to medium olivaceous-brown, subhyaline at the apex, smooth or almost so, sometimes minutely verruculose, walls usually distinctly thickened, sometimes even two-layered, up to 1(-2) μm thick, protoplasm granular, often clearly contrasting from the outer wall. Conidiogenous cells integrated, terminal and intercalary, cylindrical-oblong, slightly to distinctly geniculate-sinuous, nodulose with conidiogenous loci confined to swellings or lateral shoulders, 30-110 μm long, proliferation percurrent to sympodial, with a single or three, sometimes up to five geniculations per cell, usually only a single locus per swelling, protuberant, very prominent, short cylindrical, peg-like, clearly composed of a dome and surrounding rim, dome often higher than the periclinal rim, broad, somewhat paler than rim, conically narrowed, (2-)2.5-4 μm wide, up to 2 μm high, thickened and darkened-refractive.

Conidia solitary, sometimes in short unbranched chains of two or three, straight to slightly curved, young conidia small, 0-1-septate, broadly ovoid to pyriform, 15-26 × (9-)11-16(-18) μm [av. ± SD, 19.2 (± 4.3) × 14.2 (± 3) μm], first septum somewhat in the upper half, the upper cell is much smaller but gradually extending as the conidium matures, mature conidia 1-3-septate, broadly pyriform, cylindrical-oblong or soleiform, usually with a distinctly bulbous base, 30-55 × 12-19(-21) μm [av. ± SD, 41.5 (± 6.8) × 17.1 (± 2.1) μm], broadest part of conidia usually at the bulbous base, mostly attenuated towards the basal septum, septa becoming sinuous with age, pale to medium olivaceous-brown or brown, usually echinulate, sometimes coarsely verrucose, walls distinctly thickened, up to 2 μm thick, often appearing layered with a large lumen in the centre of the cell, broadly rounded to flattened at apex and base, hila often very prominent, often peg-like elongated, up to 3 μm long, with age becoming less prominent, visible as a thickened flat plate just below the outer echinulate wall layer, slightly raised towards the middle, 2-3.5 μm diam, thickened and darkened-refractive; microcyclic conidiogenesis not observed.

Cultural characteristics: Colonies on PDA attaining 6 mm diam after 14 d at 25 °C, whitish, smoke-grey to pale olivaceous-grey due to abundant aerial mycelium, olivaceous-black reverse, margin narrow, white, more or less crenate, aerial mycelium zonate, fluffy, covering most of the colony, mainly in the colony centre, growth convex to raised, deep into the agar, with age few large prominent exudates formed, sparingly sporulating. Colonies on MEA attaining 7 mm diam after 14 d at 25 °C, olivaceous-grey, pale olivaceous-grey to pale rosy-buff due to abundant aerial mycelium covering almost the whole colony, iron-grey reverse, margin colourless or white, broad, regular, more or less glabrous, aerial mycelium fluffy, dense, high, growth convex to umbonate, sometimes with elevated colony centre, prominent exudates lacking, sporulation sparse. Colonies on OA attaining 8 mm diam after 14 d at 25 °C, white, pale buff to pale olivaceous-grey in the centre, margin grey-olivaceous, olivaceous- to iron-grey reverse, margin entire edge or somewhat undulate, somewhat feathery, growth raised with a somewhat depressed centre forming an elevated outer rim, without prominent exudates, sporulation more abundant.

Specimen examined: New Zealand, Auckland, Mt. Albert, Carrington Road, Unitec Campus, isolated from large leaf lesions on Iris sp. (Iridaceae), 15 Aug. 2004, C.F. Hill, CBS-H 19861, holotype, culture ex-type CBS 116463 = LYN 1065 = ICMP 15579.

Substrate and distribution: On living leaves of Iris sp.; New Zealand.

Notes: Cladosporium pseudiridis closely resembles C. iridis, a common and widespread species causing leaf spots on numerous Iris spp. and a few additional hosts of the host family Iridaceae, but the latter species is easily distinguishable by having longer and narrower, more frequently septate conidia, (18-)30-75(-87) × (7-)10-16(-18) μm, (0-)2-6(-7)-septate.

It is unlikely that C. pseudiridis is of New Zealand origin since the genus Iris is not indigenous to New Zealand. All Iris species that are found in this country have been introduced, mainly for horticultural purposes. The species is, therefore, probably more common than indicated above. However, within the course of the recent monographic studies in the genus Cladosporium numerous herbarium specimens, mainly of European origin, have been examined and proved to be correctly identified agreeing with the species concept of C. iridis. Additional collections and cultures are necessary to determine its distribution.

Cladosporium ramotenellum K. Schub., Zalar, Crous & U. Braun, sp. nov. MycoBank MB504577. Figs ​Figs31, 31, ​,3232 and ​and3333.

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Fig. 31.

Cladosporium ramotenellum (CPC 12043). Conidiophores and conidia. Scale bar = 10 μm. K. Schubert del.

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Fig. 32.

Cladosporium ramotenellum (CPC 12043). A, C. Macronematous conidiophore. B. Conidial chain. D. Micronematous conidiophore. E. Ramoconidia and conidia. Scale bars = 10 μm.

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Fig. 33.

Cladosporium ramotenellum (CPC 12043). A. Survey of colony development showing a large bulbous “foot cell” that gives rise to conidiophores, which can be branched. B. Details of conidiophores showing secondary ramoconidia and conidia. The inset shows scar formation on a conidiophore. C. Conidiophore and several conidia. D. Details of ornamentation on conidia. Note the wide, but relatively low ornamentation units. E. A micrograph illustrating the organisation within a conidiophore. Scale bars A-D = 5 μm, E = 10 μm.

Etymology: Refers to the morphological similarity with Cladosporium tenellum.

Differt a Cladosporio cladosporioide conidiophoris et conidiis leniter angustioribus, 2-4(-5) μm latis, conidiis 0-2(-3)-septatis, semper verruculosis; et a Cladosporio tenello locis conidiogenis non numerosis et non aggregatos ad apicem, conidiis longioribus et angustioribus, 2.5-35 × 2-4(-5) μm, 0-3-septatis.

Mycelium unbranched or only sparingly branched, 1.5-4 μm wide, septate, without swellings and constrictions, hyaline or subhyaline, smooth, sometimes irregularly rough-walled, walls unthickened. Conidiophores solitary, macronematous and micronematous, arising as lateral branches of plagiotropous hyphae or terminally from ascending hyphae, erect, straight or slightly flexuous, cylindrical, neither geniculate nor nodulose, without head-like swollen apices or intercalary swellings, unbranched, sometimes branched, branches often only as short lateral prolongations, mainly formed below a septum, 14-110 × 2-4 μm, septate, not constricted at the septa, subhyaline to pale olivaceous or brown, smooth to minutely verruculose, walls unthickened, sometimes guttulate. Conidiogenous cells integrated, terminal, sometimes also intercalary, cylindrical, not geniculate, non-nodulose, 10-28(-50) μm long, proliferation sympodial, with few conidiogenous loci, mostly 1-3, loci sometimes situated on small lateral prolongations, protuberant, 0.5-1.5(-2) μm diam, thickened and somewhat darkened-refractive. Ramoconidia formed, cylindrical-oblong, up to 47 μm long, 2-4 μm wide, 0-1-septate, rarely up to 4-septate, subhyaline to very pale olivaceous, smooth or almost so, with a broadly truncate base, without any dome and raised rim, 2-3 μm wide, not thickened but somewhat refractive. Conidia numerous, polymorphous, catenate, in branched chains, straight, sometimes slightly curved, small terminal conidia numerous, globose, subglobose or ovoid, obovoid or limoniform, 2.5-7 × 2-4(-4.5) μm [av. ± SD, 5.1 (± 1.3) × 3.1 (± 0.6) μm], aseptate, without distal hilum or with a single apical scar, intercalary conidia ellipsoid to subcylindrical, 8-15 × 3-4(-4.5) μm [av. ± SD, 11.5 (± 2.4) × 3.6 (± 0.5) μm], 0-1-septate; secondary ramoconidia subcylindrical to cylindrical-oblong, 17-35 × 3-4(-5) μm [av. ± SD, 22.5 (± 5.6) × 3.7 (± 0.5) μm], 0-3-septate, not constricted at the septa, subhyaline to very pale olivaceous, minutely verruculose (granulate under SEM), walls unthickened or almost so, apex broadly rounded or slightly attenuated towards apex and base, sometimes guttulate, hila protuberant, conspicuous, 0.8-1.5(-2) μm diam, somewhat thickened and darkened-refractive; microcyclic conidiogenesis occurring.

Cultural characteristics: Colonies on PDA reaching 46-49 mm diam after 14 d at 25 °C, olivaceous to grey-olivaceous due to abundant sporulation, appearing zonate in forming concentric zones, margin entire edge to slightly undulate, white, glabrous, aerial mycelium absent or sparse, growth flat with a somewhat folded and wrinkled colony centre, without prominent exudates, sporulation profuse. Colonies on MEA reaching 48-49 mm diam after 14 d at 25 °C, grey-olivaceous to olivaceous-grey, velvety, olivaceous-grey to iron-grey reverse, margin entire edge to undulate, radially furrowed, colourless, glabrous to feathery, aerial mycelium sparse, diffuse, growth flat with slightly elevated colony centre, distinctly wrinkled, prominent exudates not formed, abundantly sporulating. Colonies on OA attaining 40 mm diam after 14 d at 25 °C, grey-olivaceous, margin entire edge, colourless or white, glabrous, aerial mycelium absent or sparse, growth flat, without exudates, sporulation profuse.

Specimens examined: Slovenia, Ljubljana, isolated from an air conditioning system (bathroom), 2004, M. Butala, CBS 121627 = CPC 12047 = EXF-967; Sečovlje, isolated from hypersaline water from reverse ponds, salterns, 2005, P. Zalar, CBS-H 19862, holotype, isotype HAL 2026 F, culture ex-type CBS 121628 = CPC 12043 = EXF-454.

Substrate and distribution: Hypersaline water, air; Slovenia.

Notes: Cladosporium ramotenellum, which appears to be a saprobe in air and hypersaline water, morphologically resembles C. cladosporioides and C. tenellum K. Schub., Zalar, Crous & U. Braun, but is quite distinct from C. cladosporioides by having somewhat narrower conidiophores and conidia, 2-4(-5) μm wide, and 0-3-septate, always minutely verruculose conidia. Cladosporium tenellum, a newly introduced species (see below) isolated from hypersaline water and plant material, possesses conidiophores with numerous conidiogenous loci, usually crowded towards the apex forming sympodial clusters of pronounced scars, and shorter and somewhat wider, 0-1(-2)-septate conidia, 3-20(-28) × (2.5-)3-5(-6) μm. Besides these morphological differences, C. ramotenellum is faster growing in culture than C. tenellum.

Cladosporium arthrinioides Thüm. & Beltr. and C. hypophyllum Fuckel are also close to C. ramotenellum, but C. arthrinioides, known from Italy on leaves of Bougainvillea spectabilis, deviates in having shorter and wider, 0-1(-2)-septate, mostly smooth conidia (2-18 × 2-6.5 μm) which become larger and more frequently septate with age (up to 32 μm long and with up to four septa); and C. hypophyllum occurring in Europe on leaves of Ulmus minor differs in having often mildly to distinctly geniculate-sinuous, sometimes subnodulose conidiophores and shorter and somewhat wider, 0-1(-3)-septate conidia, 4-17(-19) × 2-5 μm, becoming distinctly swollen, darker, longer and wider with age, 5-7 μm, with the septa often being constricted (Schubert 2005).

Cladosporium sinuosum K. Schub., C.F. Hill, Crous & U. Braun, sp. nov. MycoBank MB504578. Figs ​Figs3434-​-3535.

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Fig. 34.

Cladosporium sinuosum (CPC 11839). Conidiophores and conidia. Scale bar = 10 μm. K. Schubert del.

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Fig. 35.

Cladosporium sinuosum (CPC 11839). A-D. Conidiophores. E-F. Conidia. Scale bars = 10 μm.

Etymology: Refers to the usually distinctly sinuous conidiophores.

Differt a Cladosporio herbaro conidiophoris distincte sinuosis, conidiis solitariis vel breve catenatis, catenis non ramosis, echinulatis.

Mycelium sparingly branched, 1-7 μm wide, septate, not constricted at the septa, subhyaline to pale brown, smooth to minutely verruculose, walls unthickened or slightly thickened, sometimes with small swellings. Conidiophores arising laterally from plagiotropous hyphae or terminally from ascending hyphae, erect, more or less straight to flexuous, often once or several times slightly to distinctly geniculate-sinuous, sometimes even zigzag-like, nodulose with small to large lateral shoulders, shoulders somewhat distant from each other or in close succession giving them a knotty/gnarled appearance, unbranched or once branched, 25-260 × 5-7 μm, shoulders up to 10 μm wide, pluriseptate, septa sometimes in short succession, not constricted at the septa, pale brown to medium brown, smooth to minutely verruculose, walls thickened, often distinctly two-layered, up to 1 μm thick. Conidiogenous cells integrated, terminal or intercalary, often slightly to distinctly geniculate-sinuous, nodulose with small to large laterally swollen shoulders, 8-30 μm long, proliferation sympodial, with a single or up to three conidiogenous loci, usually confined to lateral shoulders, protuberant, often denticle-like or on the top of short cylindrical stalk-like prolongations, 1.2-2(-2.2) μm diam, mainly 2 μm, somewhat thickened and darkened-refractive, dome often slightly higher than the surrounding rim. Conidia solitary or in short unbranched chains with up to three conidia, straight, obovoid, oval, broadly ellipsoid to subcylindrical or sometimes clavate (broader at the apex), 9-21 × (5-)6-8 μm [av. ± SD, 14.5 (± 2.5) × 6.6 (± 0.7) μm], 0-1-septate, not constricted at the septa, septum more or less median, pale greyish brown, densely echinulate, spines up to 1 μm long, walls thickened, apex mostly broadly rounded or sometimes attenuated, towards the base mostly distinctly attenuated forming a peg-like prolongation, up to 2 μm long, hila protuberant, 1.2-2 μm diam, mainly 2 μm, somewhat thickened and darkened-refractive; microcyclic conidiogenesis not observed.

Cultural characteristics: Colonies on PDA attaining 20 mm diam after 14 d at 25 °C, pale olivaceous-grey due to abundant aerial mycelium, olivaceous-grey towards margins, iron-grey to olivaceous-black reverse, margin regular, entire edge, aerial mycelium abundant, cottony, dense, high, growth regular, low convex, radially furrowed in the centre, growing deep into the agar, with age numerous small to large prominent exudates, sporulation sparse. Colonies on MEA attaining 16 mm diam after 14 d at 25 °C, white to pale smoke-grey, fawn reverse, velvety, margin undulate, glabrous, aerial mycelium abundant, dense, high, fluffy, growth raised with elevated colony centre, laterally furrowed, without prominent exudates. Colonies on OA attaining 18 mm diam after 14 d at 25 °C, olivaceous, white to pale olivaceous-grey in the centre due to abundant aerial mycelium, olivaceous-grey reverse, margin white, entire edge, glabrous, aerial mycelium loose to dense, high, fluffy to felty, growth flat to low convex, regular, without prominent exudates, sporulating.

Specimen examined: New Zealand, Te Anau, isolated from leaves of Fuchsia excorticata (Onagraceae), 31 Jan. 2005, A. Blouin, Hill 1134A, CBS-H 19863, holotype, culture ex-type CBS 121629 = CPC 11839 = ICMP 15819.

Substrate and distribution: On living leaves of Fuchsia excorticata; New Zealand.

Notes: This new species is well characterised by its slightly to distinctly geniculate-sinuous, often zigzag-like conidiophores and its conidia formed solitary or rarely in short unbranched chains and is therefore morphologically not comparable with any of the species described until now. Most Cladosporium species with conidia usually formed solitary or in short unbranched chains have previously been treated as species of the genus Heterosporium Klotzsch ex Cooke, now considered to be synonymous with Cladosporium. All of them, including the newly introduced C. arthropodii K. Schub. & C.F. Hill from New Zealand, which also belongs to this species complex (Braun et al. 2006), possess very large and wide, often pluriseptate conidia quite distinct from those of C. sinuosum (David 1997). Cladosporium alopecuri (Ellis & Everh.) U. Braun, known from the U.S.A. on Alopecurus geniculatus is also quite different by having larger and wider conidia, 20-40 × 7-13(-15) μm, and wider conidiogenous loci and conidial hila, 3.5-5 μm diam (Braun 2000).

Cladosporium herbarum is superficially similar but the conidiophores of the latter species are sometimes only slightly geniculate-sinuous but never zigzag-like and the verruculose to verrucose conidia are frequently formed in unbranched or branched chains.

Cladosporium spinulosum Zalar, de Hoog & Gunde-Cimerman, Studies in Mycology 58: 180. 2007 - this volume. Fig. 36.

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Fig. 36.

Cladosporium spinulosum (CPC 12040). A. Overview on agar surface with conidiophores arising from the surface. The spore clusters on the conidiophore are very compact. Note several simple, tubular conidiophore ends. The inset shows details of a conidium showing two pronounced hila and a unique, very distinct ornamentation on the cell wall. B. Conidiophore with globose or subsphaerical secondary ramoconidia and conidia. Note the newly forming cells and hila. C. Two conidiophores. D. Details of spores and spore formation. E. The end of a conidiophore and two scars. Scale bars: A = 20 μm, A (inset) = 1 μm, B, D-E = 5 μm, C = 10 μm.

Note: This new species is described and illustrated in Zalar et al. (2007 - this volume).

Cladosporium subinflatum K. Schub., Zalar, Crous & U. Braun, sp. nov. MycoBank MB504579. Figs ​Figs37, 37, ​,3838 and ​and3939.

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Fig. 37.

Cladosporium subinflatum (CPC 12041). Macro- and micronematous conidiophores and conidia. Scale bar = 10 μm. K. Schubert del.

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Fig. 38.

Cladosporium subinflatum (CPC 12041). A-C. Macronematous conidiophores. D-E. Conidia. Scale bar = 10 μm.

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Fig. 39.

Cladosporium subinflatum (CPC 12041). A-G. Images of an 11-d-old culture on SNA. A. Overview of colony with clusters of conidia and aerial hyphae. Many of the hyphae have a collapsed appearance. B. Detail of colony with conidiophores, conidia and aerial hyphae that are partly collapsed. C. Detail of a conidiophore end and a secondary ramoconidium. Note the scars at the end of the conidiophore. D. Details of conidia and ornamentation. The ornamentation consists out of markedly defined units, which have a relatively large distance from each other. Note the hilum on the right conidium. E. Conidiophore with large scars and conidia. F. Different blastoconidia with very early stages of new spore formation in the middle of the picture. G. Pattern of spore development. Scale bars: A = 20 μm, B, E-G = 5 μm, C = 10 μm, D = 2 μm.

Etymology: Refers to its nodulose conidiophores.

Differt a Cladosporio bruhnei conidiophoris cum nodulis angustioribus, 3-6.5 μm latis, conidiis brevioribus, 4-17(-22) μm longis, spinulosis, cum spinulis ad 0.8 μm longis; et a Cladosporio spinuloso conidiophoris nodulosis, conidiis spinulosis, cum spinulis brevioribus, ad 0.8 longis, locis conidiogenis et hilis latioribus, (0.5-)1-2 μm latis.

Mycelium unbranched or occasionally branched, 1.5-3 μm wide, later more frequently branched and wider, up to 7 μm wide, septate, not constricted at the septa, hyaline or subhyaline, almost smooth to somewhat verruculose or irregularly rough-walled, walls unthickened. Conidiophores mainly macronematous, sometimes also micronematous, arising terminally from ascending hyphae or laterally from plagiotropous hyphae, erect or subdecumbent, straight or flexuous, sometimes bent, cylindrical, nodulose, usually with small head-like swellings, sometimes swellings also on a lower level or intercalary, occasionally geniculate, unbranched, occasionally branched, (5-)10-270 × (1.5-)2.5-4.5(-5.5) μm, swellings 3-6.5 μm wide, aseptate or with few septa, not constricted at the septa, pale brown, pale olivaceous-brown or somewhat reddish brown, smooth, usually verruculose or irregularly rough-walled and paler, subhyaline towards the base, walls thickened, sometimes appearing even two-layered, up to 1 μm thick. Conidiogenous cells integrated, usually terminal or conidiophores reduced to conidiogenous cells, cylindrical, nodulose, usually with small head-like swellings with loci confined to swellings, sometimes geniculate, 5-42 μm long, proliferation sympodial, with several loci, up to four situated at nodules or on lateral swellings, protuberant, conspicuous, denticulate, (0.8-)1-2 μm diam, thickened and darkened-refractive. Conidia catenate, in branched chains, more or less straight, numerous globose and subglobose conidia, ovoid, obovoid, broadly ellipsoid to cylindrical, 4-17(-22) × (2.5-)3.5-5.5(-7) μm [av. ± SD, 11.7 (± 4.6) × 4.5 (± 0.8) μm], 0-1(-2)-septate, not constricted at septa, pale brown or pale olivaceous-brown, ornamentation variable, mainly densely verruculose to echinulate (loosely muricate under SEM), spines up to 0.8 μm high, sometimes irregularly verrucose with few scattered tubercles or irregularly echinulate, walls unthickened or slightly thickened, apex rounded or slightly attenuated towards apex and base, hila conspicuous, protuberant, denticulate, 0.5-2 μm diam, thickened and darkened-refractive; microcyclic conidiogenesis observed.

Cultural characteristics: Colonies on PDA attaining 29 mm diam after 14 d at 25 °C, olivaceous-black to olivaceous-grey towards margin, margin regular, entire edge, narrow, colourless to white, glabrous to feathery, aerial mycelium formed, fluffy, mainly near margins, growth flat, somewhat folded in the colony centre, deep into the agar, few prominent exudates formed with age, sporulation profuse. Colonies on MEA attaining 25 mm diam after 14 d at 25 °C, olivaceous-grey to olivaceous due to abundant sporulation in the colony centre, pale greenish grey towards margin, iron-grey reverse, velvety to powdery, margin crenate, narrow, white, glabrous, radially furrowed, aerial mycelium diffuse, growth convex with papillate surface, wrinkled colony centre, without prominent exudates, sporulation profuse. Colonies on OA attaining 26 mm diam after 14 d at 25 °C, olivaceous, iron-grey to greenish black reverse, growth flat, deep into the agar, with a single exudate, abundantly sporulating.

Specimen examined: Slovenia, Sečovlje, isolated from hypersaline water from crystallization ponds, salterns, 2005, S. Sonjak, CBS-H 19864, holotype, isotype HAL 2027 F, culture ex-type CBS 121630 = CPC 12041 = EXF-343.

Substrate and distribution: Hypersaline water; Slovenia.

Notes: Cladosporium subinflatum, an additional saprobic species isolated from hypersaline water, was at first identified as C. spinulosum, but proved to be both morphologically as well as phylogenetically distinct from the latter species in having somewhat wider [(1.5-)2.5-4.5(-5.5) μm], nodulose macronematous conidiophores with conidiogenous loci confined to swellings, wider conidiogenous loci and hila, (0.8-)1-2 μm, and spiny conidia with shorter spines than in C. spinulosum (up to 0.8 μm versus 0.5-1.3 μm long) (Zalar et al. 2007). With its narrow, nodulose macronematous conidiophores and catenate conidia, C. bruhnei is morphologically also similar but differs by having conidiophores with wider swellings, (4-)5-8 μm, and longer conidia 4-24(-31) μm, rarely up to 40 μm long which are minutely verruculose to verrucose but not spiny.

Cladosporium subtilissimum K. Schub., Dugan, Crous & U. Braun, sp. nov. MycoBank MB504580. Figs ​Figs40, 40, ​,4141 and ​and4242.

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Fig. 40.

Cladosporium subtilissimum (CBS 113754). Macro- and micronematous conidiophores and conidia. Scale bar = 10 μm. K. Schubert del.

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Fig. 41.

Cladosporium subtilissimum (CBS 113754). A-C. Macronematous conidiophores. D. Conidial chain. E. Micronematous conidiophore. F-G. Conidia. Scale bars = 10 μm.

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Fig. 42.

Cladosporium subtilissimum (CBS 113754). A. Overview on the organisation of spore formation. The micrograph shows a large basal secondary ramoconidium which has chains of secondary ramoconidia, intercalary and small terminal conidia. The conidia are formed in rows of often three cells. Note the size difference in the different cells. B. Conidiophore showing very pronounced scars that almost appear as branches. C. Detail of (A), illustrating the scar formation between the cells. D. Conidia during different stages of formation. E. Details of pronounced hila, and prominent ornamentation on secondary ramoconidia with the central dome-formed area. F. Different conidia and hila. Scale bars: A = 10 μm, B-D, F = 5 μm, E = 2 μm.

Etymology: Refers to its narrow conidiophores and conidia.

Differt a Cladosporio cladosporioide conidiophoris et conidiis semper asperulatis ad verruculosis, conidiis 0-1(-2)-septatis.

Mycelium unbranched or sparingly branched, 1-5 μm wide, septate, without swellings and constrictions, hyaline to subhyaline or pale brown, smooth to minutely verruculose, walls unthickened or almost so, protoplasm somewhat guttulate or granular. Conidiophores macronematous and micronematous, arising laterally from plagiotropous hyphae or terminally from ascending hyphae, erect, straight to slightly flexuous, filiform to cylindrical-oblong, non-nodulose, sometimes geniculate towards the apex, unbranched or once branched, branches short to somewhat longer, usually formed below a septum, sometimes only short, denticle-like or conical, 25-140 × 2-4 μm, 0-4-septate, not constricted at the septa, subhyaline to pale brown, almost smooth, minutely verruculose to verruculose, sometimes irregularly rough-walled in the lower part, walls unthickened or slightly thickened, protoplasm guttulate or somewhat granular. Conidiogenous cells integrated, terminal or pleurogenous, sometimes also intercalary, filiform to narrowly cylindrical, non-nodulose, sometimes geniculate, 14-57 μm long, with usually sympodial clusters of pronounced conidiogenous loci at the apex or on a lower level, denticle-like or situated on short lateral prolongations, up to five loci, intercalary conidiogenous cells usually with a short denticle-like lateral outgrowth below a septum, protuberant, denticulate, somewhat truncate, 1.2-2 μm diam, thickened and darkened-refractive. Ramoconidia sometimes occurring, conidiogenous cells seceding at one of the upper septa of the conidiophore and behaving like conidia, filiform or cylindrical, 20-40(-55) μm long, 1.5-4 μm wide, 0-1-septate, concolorous with conidiophores, not attenuated towards apex and base, base broadly truncate, non-cladosporioid, without any dome and raised rim, 2-3.5 μm wide, neither thickened nor darkened, sometimes slightly refractive. Conidia catenate, in branched chains, up to 12 or even more in a chain, straight, small terminal conidia numerous, subglobose, narrowly obovoid, limoniform or fusiform, 4-9 × 2-3.5 μm [av. ± SD, 6.4 (± 1.5) × 2.8 (± 0.4) μm], with up to three distal scars, aseptate, hila (0.5-)0.8-1 μm diam, intercalary conidia narrowly ellipsoid, fusiform to subcylindrical, 9-18 × 3-4(-6) μm [av. ± SD, 13.0 (± 2.5) × 3.8 (± 0.3) μm], 0(-1)-septate, hila 1-1.2(-1.8) μm diam, with up to four distal scars, secondary ramoconidia ellipsoid, fusiform or subcylindrical, (13-)17-32(-37) × 3-5(-6) μm [av. ± SD, 21.4 (± 4.4) × 4.1 (± 0.5) μm], 0-1(-2)-septate, septum median or somewhat in the lower half, usually not constricted at the septa, with up to six distal hila crowded at the apex, hila (1.2-)1.5-2(-2.5) μm diam, apex often somewhat laterally enlarged or prolonged with hila crowded there, very pale or pale brown or olivaceous-brown, minutely verruculose to verruculose (granulate under SEM), walls unthickened or only slightly thickened, often slightly attenuated towards apex and base, protoplasm often guttulate or granular, hila protuberant, denticulate, (0.5-)0.8-2(-2.2) μm diam, thickened and darkened-refractive; microcyclic conidiogenesis occasionally observed.

Cultural characteristics: Colonies on PDA attaining 24 mm diam after 14 d at 25 °C, grey-olivaceous to olivaceous, olivaceous-grey, iron-grey or olivaceous-black reverse, velvety, margin regular, entire edge, white or pale greenish olivaceous, glabrous to feathery, aerial mycelium sparse, only few areas with abundant mycelium, diffuse, growth regular, flat or with a raised and wrinkled colony centre, radially furrowed, effuse, usually without prominent exudates, with age several exudates formed, sporulation profuse, colonies consisting of two kinds of conidiophores, short and a few longer ones. Colonies on MEA reaching 25 mm diam after 14 d at 25 °C, greenish olivaceous to grey-olivaceous in the centre, olivaceous-grey to iron-grey reverse, velvety, margin entire edge, crenate or umbonate, narrow, pale greenish olivaceous, sometimes radially furrowed, aerial mycelium absent or sparse, growth low convex with distinctly wrinkled colony centre, without prominent exudates, abundantly sporulating. Colonies on OA attaining 25 mm diam after 14 d at 25 °C, dark grey-olivaceous to olivaceous due to profuse sporulation, iron-grey reverse, sometimes releasing some olivaceous-buff pigments into the agar, velvety, margin regular, entire edge or crenate, narrow, colourless or white, glabrous or feathery, aerial mycelium sparse, growth flat with slightly raised colony centre, prominent exudates lacking, sporulation profuse.

Specimens examined: Slovenia, Sečovlje, isolated from hypersaline water from salterns (reserve pond), 2005, P. Zalar, CPC 12044 = EXF-462. U.S.A., isolated from bing cherry fruits, F. Dugan, CBS 113753; isolated from a grape berry, F. Dugan, wf 99-2-9 sci 1, CBS-H 19865, holotype, isotype HAL 2028 F, culture ex-type CBS 113754.

Excluded strains within the subtilissimum complex: Argentina, isolated from Pinus ponderosa (Pinaceae), 2005, A. Greslebin, CPC 12484, CPC 12485. U.S.A., isolated from grape berry, F. Dugan, CBS 113741, CBS 113742; isolated from grape bud, F. Dugan, CBS 113744.

Substrate and distribution: Plant material and hypersaline water; Slovenia, U.S.A.

Notes: Cladosporium cladosporioides is morphologically comparable with the new species but deviates in having usually smooth conidiophores and conidia, with the conidia being mainly aseptate. C. subtilissimum is represented by three isolates of different origins and substrates. Besides these strains, several additional isolates listed under excluded strains are morphologically indistinguishable from C. subtilissimum in culture, but genetically different, clustering in various subclades. They are indicated as Cladosporium sp. in the tree (Fig. 3).

Cladosporium tenellum K. Schub., Zalar, Crous & U. Braun, sp. nov. MycoBank MB504581. Figs ​Figs43, 43, ​,4444 and ​and4545.

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Fig. 43.

Cladosporium tenellum (CPC 12053). Macro- and micronematous conidiophores and conidia. Scale bar = 10 μm. K. Schubert del.

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Fig. 44.

Cladosporium tenellum (CPC 12053). A-C, E. Macronematous conidiophore. D. Micronematous conidiophore. F. Ramoconidium and conidia. Scale bars = 10 μm.

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Fig. 45.

Cladosporium tenellum (CPC 12053). A. A bird's eye view of a colony of C. tenellum with its very characteristic bundles of aerial hyphae. Numerous conidia are visible, formed on simple conidiophores. B. Hyphae that run on the agar surface give rise to conidiophores and numerous conidia, that are relatively rounded. C. Conidiophore ends are rather simple and have large scars. D. Hila on a secondary ramoconidium with non-ornamented area. E. Detail of the prominent ornamentation on a secondary ramoconidium. Scale bars: A = 20 μm, B = 10 μm, C, E = 2 μm, D = 5 μm.

Etymology: Refers to its narrow conidiophores and conidia.

Differt a Cladosporio cladosporioide conidiophoris et conidiis semper asperulatis, locis conidiogenis apicalibus, numerosis, hilis quoque numerosis, conidiophoris angustioribus, (1-)1.5-3.5(-4) μm latis; et a Cladosporio subtilissimo loci conidiogenis et hilis apicalibus, numerosis, angustioribus, saepe 1-1.5 μm latis, conidiis minutis numerosis, saepe globosis.

Mycelium sparingly branched, 1-3 μm wide, septate, septa often not very conspicuous, not constricted at the septa, sometimes slightly swollen, subhyaline, smooth, walls unthickened. Conidiophores macronematous and micronematous, solitary, arising terminally or laterally from plagiotropous or ascending hyphae, erect or subdecumbent, almost straight to more or less flexuous, cylindrical, sometimes geniculate towards the apex, but not nodulose, sometimes with short lateral prolongations at the apex, unbranched to once or twice branched (angle usually 30-45° degree, sometimes up to 90°), branches usually below a septum, 6-200 × (1-)2-4(-5) μm, septate, septa not very conspicuous, not constricted at the septa, subhyaline to pale brown, almost smooth to usually asperulate, walls unthickened or almost so. Conidiogenous cells integrated, terminal or intercalary, sometimes conidiophores reduced to conidiogenous cells, cylindrical, sometimes geniculate, non-nodulose, 6-40 μm long, proliferation sympodial, with several conidiogenous loci often crowded at the apex and sometimes also at a lower level, situated on small lateral shoulders, unilateral swellings or prolongations, with up to 6(-10) denticulate loci, forming sympodial clusters of pronounced scars, intercalar conidiogenous cells with short or somewhat long lateral outgrowths, short denticle-like or long branches with several scars at the apex, usually below a septum, loci protuberant, 1-1.5(-2) μm diam, thickened and darkened-refractive. Ramoconidia sometimes occurring, cylindrical, up to 32 μm long, 2.5-4 μm wide, with a broadly truncate, unthickened base, about 2 μm wide. Conidia catenate, formed in branched chains, straight, small terminal conidia globose, subglobose, ovoid, oval, 3-6 × 2.5-3.5 μm [av. ± SD, 4.5 (± 1.3) × 2.8 (± 0.4) μm], aseptate, asperulate, with 0-2 distal hila, intercalary conidia and secondary ramoconidia ellipsoid-ovoid, ellipsoid to subcylindrical, 3.5-20(-28) × (2.5-)3-5(-6) μm [av. ± SD, 12.4 (± 5.4) × 4.1 (± 0.7) μm], 0-1-septate, rarely with up to three septa, sometimes slightly constricted at the septa, subhyaline, pale brown to medium olivaceous-brown, asperulate or verruculose (muricate, granulate or colliculate under SEM), walls unthickened or slightly thickened, apex rounded or slightly to distinctly attenuated towards apex and base, often forming several apical hila, up to 7(-9), crowded, situated on small lateral outgrowths giving them a somewhat irregular appearance, hila protuberant, 0.5-1.5 μm diam, thickened and darkened-refractive; microcyclic conidiogenesis sometimes occurring.

Cultural characteristics: Colonies on PDA reaching 27-34 mm diam after 14 d at 25 °C, smoke-grey, grey-olivaceous to olivaceous-grey, olivaceous-grey to iron-grey reverse, velvety to powdery, margin regular, entire edge, narrow, colourless to white, aerial mycelium absent or sparingly formed, felty, whitish, growth regular, flat, radially furrowed, with folded and elevated colony centre, deep into the agar, with age forming few to numerous prominent exudates, sporulation profuse, few high conidiophores formed. Colonies on MEA reaching 25-44 mm diam after 14 d at 25 °C, olivaceous-grey to olivaceous- or iron-grey due to abundant sporulation in the colony centre, velvety, margin regular, entire edge, narrow, colourless, white to pale olivaceous-grey, aerial mycelium loose, diffuse, growth convex with papillate surface, radially furrowed, wrinkled, without prominent exudates, sporulating. Colonies on OA reaching 23-32 mm diam after 14 d at 25 °C, grey-olivaceous, olivaceous-grey to olivaceous due to abundant sporulation in the colony centre, olivaceous- or iron-grey reverse, velvety, margin regular, entire edge, narrow, colourless or white, aerial mycelium sparse, diffuse, floccose, growth flat to low convex, radially furrowed, wrinkled, without prominent exudates, sporulation profuse.

Specimens examined: Israel, Eilat, isolated from hypersaline water from salterns, 2004, N. Gunde-Cimerman, CBS 121633 = CPC 12051 = EXF-1083; Ein Bokek, isolated from hypersaline water of the Dead Sea, 2004, M. Ota, CBS-H 19866, holotype, isotype HAL 2029 F, culture ex-type CBS 121634 = CPC 12053 = EXF-1735. U.S.A., Seattle, University of Washington campus, isolated from Phyllactinia sp. (Erysiphaceae) on leaves of Corylus sp. (Corylaceae), 16 Sep. 2004, D. Glawe, CPC 11813.

Substrates and distribution: Hypersaline water and plant material; Israel, U.S.A.

Notes: Cladosporium subtilissimum and C. cladosporioides are morphologically comparable with the new species C. tenellum, but C. cladosporioides deviates in having usually smooth conidiophores and conidia with only few conidiogenous loci and conidial hila crowded at the apex and somewhat wider conidiophores, 3-5(-6) μm; and in C. subtilissimum the small terminal conidia are not globose but rather narrowly obovoid to limoniform, the conidiogenous loci and conidial hila are somewhat wider, (0.5-)0.8-2(-2.2) μm, and at the apices of conidiophores and conidia only few scars are formed.

Cladosporium ramotenellum, which morphologically also resembles C. tenellum, possesses longer and narrower, 0-3-septate conidia, 2.5-35 × 2-4(-5) μm, but forms only few conidiogenous loci and conidial hila at the apices of conidiophores and conidia.

Cladosporium variabile (Cooke) G.A. de Vries, Contr. Knowl. Genus Cladosporium: 85. 1952. Figs ​Figs46, 46, ​,4747 and ​and4848.

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Fig. 46.

Cladosporium variabile (CPC 12751). Macro- and micronematous conidiophores and conidia. Scale bar = 10 μm. K. Schubert del.

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Fig. 47.

Cladosporium variabile and its teleomorph Davidiella variabile (CPC 12751). A-C. Macronematous conidiophores. D, F. Micronematous conidiophores. E, G-H. Conidia. I. Twisted aerial mycelium. J. Ascomata formed on nettle stem in culture. K. Surface view of ascomal wall of textura epidermoidea. L-M. Asci. N-P. Ascospores. Q. Ascus with a sheath. Scale bars A, D, G-J, K-N = 10 μm, J = 250 μm.

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Fig. 48.

Cladosporium variabile (CPC 12753). A. Survey of hyphae that grow on the agar surface. Some of the fungal cells have a swollen appearance and could develop into a “foot cell” that gives rise to a conidiophore. B. A number of aerial hyphae obstruct the swollen, large structures on the agar surface, which give rise to conidiophores. Some of them appear ornamented. C. A series of conidia formed on a conidiophore (bottom of the micrograph). D. Detail of the ornamented conidia. The ornamentations are isolated and dispersed. Note also the ornamentation-free scar zone and the hilum of the left cell. E. Two conidia behind an aerial hypha. F. Two conidiophores forming secondary ramoconidia. Note the bulbous shape of the spore-forming apparatus. This micrograph is from an uncoated sample. Scale bars: A-C, F = 10 μm, D = 2 μm, E = 5 μm.

Basionym: Heterosporium variabile Cooke, Grevillea 5(35): 123. 1877.

• ≡ Helminthosporium variabile Cooke, Fungi Brit. Exs. Ser. 1, No. 360. 1870, nom. inval.

  • = Cladosporium subnodosum Cooke, Grevillea 17(83): 67. 1889.

Teleomorph: Davidiella variabile Crous, K. Schub. & U. Braun, sp. nov. MycoBank MB504583.

Davidiellae tassianae similis, sed ascosporis maioribus, (22-)26-30(-35) × (7-)7.5-8(-9) μm, et ascis latioribus, plus quam 18 μm.

Ascomata pseudothecial, black, superficial, situated on a small stroma, globose, up to 250 μm diam, with 1-3 ostiolate necks; ostioles periphysate, with apical periphysoids present; wall consisting of 3-6 layers of dark brown textura angularis, textura epidermoidea in surface view. Asci fasciculate, bitunicate, subsessile, obovoid to broadly ellipsoid, straight to slightly curved, 8-spored, 70-95 × 18-28 μm; with pseudoparenchymatal cells of the hamathecium persistent. Ascospores tri- to multiseriate, overlapping, hyaline, with irregular lumina, thick-walled, straight to slightly curved, fusoid-ellipsoidal with obtuse ends, widest near the middle of the apical cell, medianly 1-septate, not to slightly constricted at the septum, at times developing a second septum in each cell, several ascospores with persistent, irregular mucoid sheath, (22-)26-30(-35) × (7-)7.5-8(-9) μm.

Mycelium immersed and superficial, irregularly branched, aerial mycelium twisted and spirally coiled, 1-3 μm wide, septate, sometimes with swellings or small lateral outgrowths, hyaline to subhyaline, smooth, walls unthickened, hyphae which give rise to conidiophores somewhat wider, 3-4.5 μm, subhyaline to pale brown, almost smooth to minutely verruculose, sometimes enveloped by a polysaccharide-like cover. Conidiophores usually macronematous, but also micronematous, arising terminally from ascending hyphae or laterally from plagiotropous hyphae. Macronematous conidiophores erect, more or less straight to flexuous, often distinctly geniculate-sinuous forming lateral shoulders or unilateral swellings, sometimes zigzag-like or somewhat coralloid, nodulose, swellings at first terminal, then becoming lateral due to sympodial proliferation, often as distinct lateral shoulders, unbranched, sometimes once branched, 6-180 × (2.5-)3-6 μm, swellings (3-)6-11 μm wide, septate, not constricted at the septa, pale to medium olivaceous-brown or brown, usually verruculose, walls somewhat thickened, about 1 μm thick, sometimes appearing to be two-layered. Conidiogenous cells integrated, terminal and intercalary, cylindrical, nodulose to nodose, with a single or two swellings per cell, swellings apart from each other or formed in short succession, loci confined to swellings, up to six per node, protuberant, 1-2 μm diam, thickened and darkened-refractive. Micronematous conidiophores erect, straight to slightly flexuous, unbranched, usually without swellings, filiform to narrowly cylindrical, sometimes only as short lateral outgrowths of hyphae, often almost indistinguishable from hyphae, up to 50 μm long, 1.5-2.5(-3) μm wide, longer ones pluriseptate, septa appear to be somewhat more darkened, with very short cells, 4-12 μm long, subhyaline to pale brown, smooth, walls unthickened or almost so. Conidiogenous cells integrated, usually terminal, rarely intercalary, cylindrical, non-nodulose, with a single, two or few conidiogenous loci at the distal end, protuberant, up to 2 μm diam, thickened and darkened-refractive. Conidia catenate, in branched chains, straight, subglobose, obovoid, oval, broadly ellipsoid to cylindrical, sometimes clavate, 4-26(-30) × (3.5-)5-9(-10) μm [av. ± SD, 16.8 (± 6.9) × 6.5 (± 1.4) μm], 0-3-septate, usually not constricted at the septa, septa becoming sinuous with age, often appearing to be darkened, pale to medium or even dark brown or olivaceous-brown, verruculose to densely verrucose or echinulate (granulate under SEM), walls slightly to distinctly thickened in larger conidia, apex and base broadly rounded, sometimes broadly truncate or somewhat attenuated, apex and base often appear to be darkened or at least refractive, hila protuberant to somewhat sessile (within the outer wall ornamentation), (0.8-)1-2 μm diam, thickened and darkened-refractive; microcyclic conidiogenesis occurring.

Cultural characteristics: Colonies on PDA attaining 29 mm diam after 14 d at 25 °C, olivaceous to olivaceous-grey or iron-grey, iron-grey or olivaceous-grey reverse, velvety to powdery, margin regular, entire edge to fimbriate, almost colourless, aerial mycelium whitish turning olivaceous-grey, sometimes reddish, greyish rose, woolly-felty, growth flat with elevated colony centre, somewhat folded or radially furrowed, with age forming several very small but prominent exudates, sporulation profuse. Colonies on MEA attaining 27 mm diam after 14 d at 25 °C, olivaceous-grey to iron-grey, white to pale olivaceous-grey in the centre due to abundant aerial mycelium, velvety, margin very narrow, colourless, more or less entire edge, radially furrowed, aerial mycelium fluffy to floccose, dense, growth low convex with wrinkled and folded centre, without exudates, sporulation profuse. Colonies on OA attaining 25 mm diam after 14 d at 25 °C, iron-grey or olivaceous, margin regular, entire edge, narrow, white, glabrous, aerial mycelium whitish, at first mainly in the colony centre, high, dense, floccose, growth flat, abundantly sporulating, no exudates.

Specimens examined: Great Britain, Wales, Montgomeryshire, Welshpool, Forden Vicarage, on Spinacia oleracea (Chenopodiaceae), J.E. Vize, Cooke, Fungi Brit. Exs. Ser. I, No. 360, K, holotype. U.S.A., Washington, isolated from Spinacia oleracea, 1 Jan. 2003, L. DuToit, CBS-H 19867, epitype designated here of C. variabile and D. variabile, cultures ex-epitype CBS 121635 = CPC 12753, CPC 12751.

Substrate and distribution: Leaf-spotting fungus on Spinacia oleracea; Asia (China, India, Iraq, Pakistan), Europe (Austria, Belgium, Cyprus, Denmark, France, Germany, Great Britain, Hungary, Italy, Montenegro, Netherlands, Norway, Romania, Spain, Turkey), North America (U.S.A.).

Literature: de Vries (1952: 85-88), Ellis (1971: 315), Ellis & Ellis (1985: 429), David (1995b; 1997: 94, 96-98), Ho et al. (1999: 144).

Notes: In vivo the conidia are usually longer, somewhat wider and more frequently septate, (6.5-)10-45(-55) × (4.5-)6-14(-17) μm, 0-4(-5)-septate (Schubert 2005). In culture the dimensions tend to be smaller, which was already mentioned by de Vries (1952).

This leaf-spotting fungus superficially resembles C. macrocarpum, but besides its pathogenicity to Spinacia, C. variabile differs from the latter species in having distinctly larger and more frequently septate conidia on the natural host, forming twisted and spirally coiled aerial mycelium in culture and in having lower growth rates in culture (29 mm after 14 d on PDA versus 38 mm on average in C. macrocarpum). Furthermore, the conidial septa of C. variabile are often distinctly darkened, become sinuous with age and the apex and base of the conidia often appear to be distinctly darkened. A Davidiella teleomorph has not previously been reported for this species.

Several colleagues from different countries provided material and valuable cultures without which this work would not have been possible. In this regard, we thank particularly Alina G. Greslebin (CIEFAP, Esquel, Chubut, Argentina), Frank Dugan and Lindsey DuToit (Washington State Univ., U.S.A.), and Annette Ramaley (Colorado, U.S.A.). Konstanze Schubert was financially supported by a Synthesys grant (No. 2559) which is gratefully acknowledged. We thank Marjan Vermaas for preparing the photographic plates, Rianne van Dijken for the growth studies, and Arien van Iperen for maintaining the cultures studied. Bert Gerrits van den Ende is acknowledged for assisting with the molecular data analyses.