ser. Noonimiarum ser. Whitfieldiorum
Fig. 17. Combined phylogeny forBenA,CaMandRPB2data sets showing the phylogenetic relation of species and series withinAspergillussubgen.Polypaecilum. The BI posterior probability (pp) values and bootstrap percentages of the maximum likelihood (ML) analysis are presented at the nodes; fully supported branches are thickened. Values less than 70 % bootstrap support (ML) or less than 0.95 posterior probability (Bayesian analysis) are indicated with a hyphen or not shown. The bar indicates the number of substitutions per site. The phylogram is rooted withHamigera avellaneaandPenicillium expansum.
rough-walled, thick; no growth at 37 °C.Sexual morphgenerally not produced in culture, except for P. fuscum, eupenicillium-type, homo-thallic, greyish yellow; ascospores ellipsoidal, with two longitudinal flanges, convex smooth-walled; sclerotia generally absent, except inP. flavisclerotiatum (yellow) and P. tsitsikammaense (white). Series description based onPitt (1980)andHoubrakenet al.(2014b).
Included species: Penicillium ardesiacum, P. athertonense, P. brun-neoconidiatum, P. clavistipitatum, P. flavisclerotiatum, P. fuscum, P. montanense,P.tsitsikammaense,P.turcosoconidiatum.
Extrolites: The species in ser.Pinetorumare chemotaxonomically quite different. Penicillium athertonense produces viridicatins, P. flavi-sclerotiatum DTO 184-D8 produces burnettienes, while the isolates DTO 180-I1 and DTO 181-I9 produce asperfuran.Penicillium fuscum produces asperfuran, while isolates allocated toP.lapatayaeproduce kotanins, lapatins and spinulosins indicatingP.lapatayaeis a separate species. However, we followHoubrakenet al.(2014b)and consider this species as a synonym ofP.fuscumbased on molecular data.Penicillium montanense produces unique extrolites, while P. turcosoconidiatum (DTO 181-A3) produces citreoviridin and haenamindole.
Series Quercetorum Houbraken & Frisvad, ser. nov. MycoBank MB834247.
Etymology: Named after the type species of the series, Penicillium quercetorum.
Type:Penicillium quercetorumBaghd., Novosti Sist. Nizsh. Rast. 5: 110.
1968.
Diagnosis:Phylogeny: SeriesQuercetorumbelongs to subgen. Asper-gilloides, sect.Aspergilloides and is sister to seriesHoeksiorum and Livida (Fig. 18). Morphology & physiology: Colonies growing moder-ately; conidial colour en masse dull green; conidiophores mono-verticillate, smooth-walled; conidia globose, smooth; growth at 37 °C absent.Sexual morphnot observed in culture; sclerotia orange-brown.
Series description based onHoubrakenet al.(2014b).
Included species:Penicillium quercetorum.
Extrolites: No chemotaxonomic data available forP.quercetorum.
Series Saturniformia Houbraken & Frisvad, ser. nov. MycoBank MB834248.
Etymology: Named after the type species of the series, Penicillium saturniforme.
Type:Penicillium saturniforme(L. Wang & W.Y. Zhuang) Houbraken &
Samson, Stud. Mycol. 70: 48. 2011.
Diagnosis: Phylogeny: Series Saturniformia belongs to subgen.
Aspergilloides, sect.Aspergilloidesand is sister to ser.Verhageniorum (Fig. 18). Morphology & physiology: Colonies growing moderate;
conidial colouren massegreen to greyish olive; conidiophores biverti-cillate; no growth on CYA incubated at 30 °C; conidia (broadly) ellip-soidal, finely rough-walled. Sexual morph eupenicillium-type, homothallic, pinkish brown; ascospores ellipsoidal, with two very closely appressed equatorial ridges, convex smooth with sparsely scatteredfine warts or irregular ribs along the outer areas. Series description based on Wang & Zhuang (2009)andHoubrakenet al.(2014b).
Included species:Penicillium saturniforme.
Extrolites: No chemotaxonomic data available forP.saturniforme.
Series Spinulosa Houbraken & Frisvad, ser. nov. MycoBank MB834249.
Etymology: Named after the type species of the series, Penicillium spinulosum.
Type:Penicillium spinulosumThom, U.S.D.A. Bur. Animal Industr. Bull.
118: 76. 1910.
Diagnosis:Phylogeny: SeriesSpinulosa belongs to subgen. Aspergil-loides, sect.Aspergilloides and is sister to ser.Thomiorum(Fig. 18).
Colonies spreading on CYA, MEA and YES, texture (slightly)floccose;
conidial colour en masse mostly pure or dull green; conidiophores monoverticillate with vesiculate apex, smooth; conidia ornamented, finely to distinctly rough-walled, globose to subglobose; on CREA poor or good growth, acid production often absent or poor. Sexual morph unknown; sclerotia not observed in culture. Series description based on Houbrakenet al.(2014b).
Included species: Penicillium grancanariae, P. palmense, P. rose-omaculatum, P. spinulosum, P. sterculiniicola, P. subspinulosum, P. trzebinskii.
Extrolites:Penicillium spinulosumhas been reported to produce spi-nulosin (Birkinshaw & Raistrick 1931, Anslow & Raistrick 1938, Pettersson 1965). The original producing strain, IMI 091950, did not match the description ofP.spinulosum(results reported here). Peni-cillium subspinulosumproduces frequentin and palitantin (Houbraken et al.2014b), in common withP.trzebinskii;P.spinulosumproduces asperfuran, while P. sterculiniicola produces asperfuran and 12,13-deoxybrevianamide E.
Series Sublectatica Houbraken & Frisvad, ser. nov. MycoBank MB834250.
Etymology: Named after the type species of the series, Penicillium sublectaticum.
Type:Penicillium sublectaticumHoubrakenet al., Stud. Mycol. 78: 436.
2014.
Diagnosis:Phylogeny: SeriesSublectaticabelongs to subgen. Asper-gilloides, sect.Aspergilloidesand is sister to ser.Fortuita, though sta-tistical support for this relationship is lacking (Fig. 18).Morphology &
physiology: Colonies growing moderately fast or spreading; conidial colouren massein various shades of green (greyish green, dark green, dull green); conidiophores monoverticillate; growth on CYA incubated at 30 °C, no growth at 37 °C. Sexual morph unknown; sclerotia not observed in culture. Series description based on Houbraken et al.
(2014b).
Included species:Penicillium infra-aurantiacum,P.malmesburiense,P. sublectaticum.
Extrolites: Penicillium infra-aurantiacum produces citrinin, while P. malmesburienseproduces unique extrolites that have not been structure elucidated yet.
Series Thiersiorum Houbraken & Frisvad, ser. nov. MycoBank MB834251.
Etymology: Named after the type species of the series, Penicillium thiersii.
Type:Penicillium thiersiiS.W. Petersonet al., Mycologia 96: 1283. 2004.
Diagnosis: Phylogeny: Series Thiersiorumbelongs to subgen. Asper-gilloides, sect. Aspergilloides and is sister to all other series in the section (Fig. 18).Morphology & physiology: Colonies spreading; conidial colour en masse dark bluish grey; conidiophores monoverticillate, smooth or slightly roughened; conidia ellipsoidal, smooth; growth absent at 37 °C.Sexual morph eupenicillium-type, homothallic, pale brown;
ascospores ellipsoidal, with equatorial ridge, smooth orfinely roughened convex. Series description based on Peterson et al. (2004) and Houbrakenet al.(2014b).
Included species:Penicillium thiersii.
Extrolites:Penicillium thiersiiproduces thiersinines and their precursors such as 1’-O-acetylpaxilline, dehydroxypaxilline, paxilline, paspaline, PC-M5’ and PC-M6 (Li et al. 2002), decaturin B, C and D, 15-deoxyoxalicine A, oxalicine A and B (Zhang et al. 2003, Li et al.
2005) and emindole SB and thiersindole A-C (Liet al.2002, Liet al.
2003).
Series Thomiorum Houbraken & Frisvad, ser. nov. MycoBank MB834252.
Etymology: Named after the type species of the series, Penicillium thomii.
Type:Penicillium thomiiMaire, Bull. Soc. Hist. Nat. Afrique N. 8: 189.
1917.
Diagnosis:Phylogeny: SeriesThomiorum belongs to subgen. Asper-gilloides, sect.Aspergilloidesand is sister to ser.Spinulosa(Fig. 18).
Morphology & physiology: Colonies spreading on CYA, MEA and YES;
conidial colouren massedull green; conidiophores monoverticillate with a vesiculate apex, rough-walled, conidia ellipsoidal or fusiform; growth on CYA incubated at 30 °C, (5–)15–35(–45), no growth at 37 °C.
Sexual morph unknown; sclerotia commonly produced, in shades of pink (orange-pink, brownish pink). Series description based on Houbrakenet al.(2014b).
Included species:Penicillium aurantioviolaceum,P.austroafricanum,P. cartierense,P. contaminatum, P.crocicola,P.fusisporum, P. grevillei-cola,P.jejuense,P.roseoviride,P.thomii,P.valentinum,P.yezoense.
Extrolites:Penicillium thomii has been reported to produce N-acetyl-phenylalaninol and the related 2(S)-acetamido-3-phenylpropylacetate, austalides, furan-2-carboxylic acid derivatives, guaidiol A and 4,10,11-trihydroxyguaiane, pallidopenillines, penistinraistin C and the related daldinin D, sargassopenillines, thomimarides, thomimarines, VM55599 and zesteropenillines (Sobolevskaya et al. 2014, Zhuravleva et al.
2014a, b, Sobolevskaya et al. 2016a, b, 2018, Afiyatullov et al.
2017a, b, 2018).Penicillium austroafricanumproduces fumagillin and P. auirantioviolaceum produces spinulosins. Five species in series Thomiorumproduce haenamindole:P.cartierense,P.contaminatum,P. crocicola,P.roseoviride andP.yezoense; P.contaminatumalso pro-duces palitantin.
Series Verhageniorum Houbraken & Frisvad, ser. nov. MycoBank MB834253.
Etymology: Named after the type species of the series, Penicillium verhagenii.
Type:Penicillium verhageniiHoubraken, Stud. Mycol. 78: 443. 2014.
Diagnosis: Series Verhageniorum belongs to subgen. Aspergilloides, sect. Aspergilloides and is sister to ser. Saturniformia (Fig. 18).
Morphology & physiology: Colonies growing moderately; conidial colour en massevariable, in green shades with a blue element; conidiophores biverticillate, sometimes becoming divaricate by sympodial branching of the stipe at the apex, smooth orfinely roughened; conidial shape var-iable, rough-walled; no growth on CYA incubated at 30 °CSexual morph unknown; sclerotia not observed in culture. Series description based on Houbrakenet al.(2014b).
Included species:Penicillium ranomafanaense,P.verhagenii.
Extrolites:Penicillium ranomafanaenseproduces andrastin A, asterric acid, fulvic acids, gregatins and geodin; P. verhagenii produces a quinone of unknown structure.
Notes on sect.Aspergilloides and included series: Section Aspergil-loides was introduced by Pitt (1980) to accommodate Penicillium species that predominantly produce monoverticillate conidiophores in which at least a portion of the stipes terminate in vesicular swellings.
The phenotype-based infrageneric classification systems proposed in Penicilliumare generally loosely corresponding with those based on phylogenetic inference using sequence data. Houbraken & Samson (2011) proposed a sectional classification system based on the phylogenetic analysis of a combined four-gene dataset and
re-circumscribed section Aspergilloides. The majority of species belonging to this re-circumscribed section grow moderately or fast on agar media and are predominantly monoverticillate. The section was subsequently revised, and the 51 accepted species were distributed over 12 clades (Houbraken et al. 2014b). These clades are here treated as series. The relationship ofP. kiamaensewas unresolved and was therefore not accommodated in a clade; we introduced ser.
Kiamaensia for this species. After 2014, three new species were described in sect.Aspergilloides(P.fortuitum,P.improvisum, andP. jejuense). The former two species form unique lineages in the section and are therefore accommodated in unique, separate series (Fortuita, Improvisa).
The series classification is primarily based on the phylogenetic relationships of the species within the section, and this is often supported by morphology and physiology data. Growth rate, the ability to grow at 30 °C, conidiophore branching pattern and conidial shape and ornamentation were useful characters to differentiate the series of sect.Aspergilloides. The phylogenetic support was low or absent for seriesFortuita,Improvisa andKiamaensia. The phyloge-netic distance of the former two series was sufficient to accommodate them in separate series. In addition, ser.Fortuitagrows restrictedly, a feature shared with the distantly related ser.Pinetorum. Series Kia-maensia is a sister series of series Spinulosa and Thomiorum, though statistical support for this is weak. Series Spinulosa and Thomiorum are phylogenetically and phenotypically distinct. Series Kiamaensia is introduced in order to maintain monophyletic series.
The relationship between the two species in ser. Longicatenata is moderately supported in the phylogram ofHoubrakenet al.(2014b).
These species are phenotypically unrelated and this suggests that they might belong to two separate series. The discovery of more species related to this clade might show that they are actually more than one series; however, we prefer at this moment a conservative approach and maintain both species in one series.
SectionCharlesiaHoubraken & Samson, Stud. Mycol. 70: 33. 2011.
MycoBank MB563125.
Type:Penicillium charlesiiG. Sm., Trans. Brit. Mycol. Soc. 18: 90. 1933.
Description: See Peterson et al. (2005) and Houbraken & Samson (2011) (morphology, phylogeny); a modern taxonomic study on this section is lacking.
Series Costaricensia Houbraken & Frisvad, ser. nov. MycoBank MB834254.
Etymology: Named after the type species of the series, Penicillium costaricense.
Type:Penicillium costaricenseVisagieet al., Persoonia 36: 263. 2016.
Diagnosis: SeriesCostaricensiabelongs to subgen.Aspergilloides, sect.
Charlesia and is sister to series Fellutana, Indica and Phoenicea.
Morphology & physiology: Colonies restricted; conidial colouren masse turquoise to dull green; conidiophores monoverticillate, smooth; conidia subglobose, smooth-walled; growth at 37 °C absent. Sexual morph unknown; sclerotia not observed in culture. Series description based on Visagieet al.(2016b).
Included species:Penicillium costaricense.
Extrolites: Andrastin A & C (Visagieet al.2016b).
Series Fellutana Pitt, The Genus Penicillium: 263. 1980 [1979].
MycoBank MB832961.
Type:Penicillium fellutanumBiourge, Cellule 33: 262. 1923.
Diagnosis: Series Fellutana belongs to subgen.Aspergilloides, sect.
Charlesiaand is sister to ser.Indica(Fig. 18).Morphology & physiology:
Colonies growing restricted; conidial colour en masse dark green;
conidiophores monoverticillate or furcate, smooth; conidia globose or ellipsoidal, finely or distinctly rough-walled; growth at 37 °C absent.
Sexual morph unknown; sclerotia not observed in culture. Series description based onPitt (1980)andPetersonet al.(2005).
Included species:Penicillium charlesii,P.fellutanum.
Extrolites:Penicillium charlesiiin ser.Fellutanaproduces carolic acids (Clutterbucket al.1934, Clutterbucket al.1935a, b, c), an uracil nucle-oside (Maynard & Gander 1966) and exopolysaccharides (Haworthet al.
1935). Penicillium fellutanum has been reported to produce different secondary metabolites such as fellutamides (Shigemoriet al. 1991), fellutanine A-E and isofellutanine B & C (Kozlovskyet al.1997a, b, 2000), cyclosporine (Anjumet al.2012) and peniphenylanes (Zhanget al.2016).
SeriesIndicaHoubraken & Frisvad,ser.nov.MycoBank MB834255.
Etymology: Named after the type species of the series, Penicillium indicum.
Type:Penicillium indicumD.K. Sandhu & R.S. Sandhu, Canad. J. Bot.
41: 1273. 1963.
Diagnosis: Series Indica belongs to subgen. Aspergilloides, sect.
Charlesiaand is sister to ser.Fellutana(Fig. 18).Morphology & phys-iology: Colonies growing moderately fast or spreading; conidial colour en masse dull green or grey green; conidiophores predominantly monoverticillate, conspicuously vesiculate, smooth; conidia subglobose to ellipsoidal, smooth-walled; growth at 37 °C present (P.chermesinum, P. indicum) or absent (P. lunae). Sexual morph unknown; sclerotia produced inP.indicum, white to cream. Series description based onPitt (1980)andCrouset al.(2019).
Included species:Penicillium chermesinum,P.cuddlyae*,P.indicum,P. lunae* [*not included inFig. 18; more info on their phylogenetic rela-tionship, seeCrouset al.(2019)].
Extrolites:Penicillium chermesinumis reported to produce chermesins (Liu et al. 2016b), penicilliumolides (Darsih et al. 2015), PR-toxins (Darsihet al. 2015), chermesinones and terphenyllins (Huang et al.
2011) and costaclavin (Agurell 1964), and also to secrete the ribotox-ins proteribotox-ins (Hwuet al.2001).
Series Phoenicea Houbraken & Frisvad, ser. nov. MycoBank MB834256.
Etymology: Named after the type species of the series, Penicillium phoeniceum.
Type:Penicillium phoeniceumJ.F.H. Beyma, Zentralbl. Bakteriol. Par-asitenk., Abt. 2 88: 136. 1933.
Diagnosis: SeriesPhoeniceabelongs to subgen.Aspergilloides, sect.
Charlesia and is sister to series Fellutana and Indica (Fig. 18).
Morphology & physiology: Colonies growing restrictedly or moderately rapid; conidial colour en masse dull green or dull greyish blue; co-nidiophores monoverticillate, vesiculate, smooth; conidia globose, smooth-walled; growth at 37 °C present (P.phoeniceum) or absent (P. coffeae). Sexual morph unknown; sclerotia not observed in culture.
Series description based onPitt (1980)andPetersonet al.(2005).
Included species:Penicillium coffeae,P.phoeniceum.
Extrolites:Penicillium phoenicumhas been reported to produce phoe-nicin (Friedheim 1938, Posternak 1938, Curtinet al.1940, Posternak et al.1943, Steineret al.1974).
Notes on series of sect.Charlesia:Petersonet al.(2005)studied the phylogenetic relationship ofP.coffeaewithin the genusPenicillium. They showed that this species is related toP.charlesii,P.chermesinum,P. coffeae, P. fellutanum, P. indicum and P. phoeniceum; all species currently classified in sect.Charlesia. The phenotypic similarity between P.charlesii,P.fellutanum(ser.Fellutana),P.chermesinum,P.indicum
(ser.Indica), andP.coffeaeandP.phoeniceum(ser.Phoenicea) was also indicated and these groups of species (here treated as series) could be distinguished using colony growth rates and conidiophore complexity.Penicillium lunaeandP.costaricensewere described after Petersonet al.(2005); the former species belongs to ser.Indicaand the latter represents a single species series.
SectionCinnamopurpureaHoubraken & Samson, Stud. Mycol. 70: 34.
2011. MycoBank MB563128.
Type: Penicillium cinnamopurpureum Udagawa, J. Agric. Food Sci., Tokyo 5: 1. 1959.
Description: SeeHoubraken & Samson (2011), Peterson et al.(2015) (morphology, phylogeny).
SeriesCinnamopurpureaHoubraken & Frisvad,ser.nov.MycoBank MB834257.
Etymology: Named after the type species of the series, Penicillium cinnamopurpureum.
Type: Penicillium cinnamopurpureum Udagawa, J. Agric. Food Sci., Tokyo 5: 1. 1959.
Diagnosis:Phylogeny: SeriesCinnamopurpureabelongs to subgen.
Aspergilloides, sect. Cinnamopurpurea and is a sister series of IdahoensiaandNodula(Fig. 18).Morphology & physiology: Colonies restricted; conidial colouren masseblue-green, grey-green or pale green; conidiophores monoverticillate; stipes smooth, short, often less than 50μm in length; conidia globose to subglobose, sometimes (broadly) ellipsoidal, smooth; growth at 37 °C absent (P.gravinicasei, P. parvulum) or present (P. cinnamopurpureum).Sexual morphnot observed in culture (P. gravinicasei, P. parvulum) or present (P. cinnamopurpureum), eupenicillium-type, homothallic, pinkish cinna-mon to brown; ascospores ellipsoidal, with two close equatorial ridges, valves (finely) rough-walled, warted viewed by SEM; sclerotia not observed in culture. Series description based on Pitt (1980), Stolk & Samson (1983), Peterson & Horn (2009) and Anelli et al.
(2018).
Included species: Penicillium cinnamopurpureum, P. gravinicasei, P. parvulum.
Extrolites: Penicillium cinnamopurpureum and P. parvulum produce some red anthraquinones of unknown structure.
Series Idahoensia Houbraken & Frisvad, ser. nov. MycoBank MB834258.
Etymology: Named after the type species of the series, Penicillium idahoense.
Type:Penicillium idahoensePaden, Mycopathol. Mycol. Appl. 43: 259.
1971.
Diagnosis:Phylogeny: SeriesIdahoensiabelongs to subgen. Aspergil-loides, sect. Cinnamopurpureaand is sister to ser.Nodula(Fig. 18).
Morphology & physiology: Colonies restricted; conidial colouren masse in shades of green, grey-green, blue-green or pale green; conidiophores monoverticillate, occasionally with an additional branch; stipes short, smooth, often vesiculate; conidia varying from globose to ellipsoidal, mostly smooth orfinely roughened, sometimes conspicuously spinulose (P.malacaense); growth at 37 °C generally absent, sometimes present (P. idahoense, (Visagie et al. 2014a). Sexual morph generally not observed in culture, only present inP. idahoense, eupenicillium-type, homothallic, (dark) brown; ascospores ellipsoidal, with two close equatorial ridges, valves (finely) smooth-walled under light microscope, warted viewed by SEM; sclerotia absent or present (P.fluviserpens,P. lemhiflumine), brown. Series description based on Paden (1971), Ramírez (1982), Stolk & Samson (1983), Visagieet al.(2014a) and Petersonet al.(2015).
Included species:Penicillium colei,P.cvjetkovicii,P.ellipsoideosporum, P. fluviserpens, P. idahoense, P. infrapurpureum, P. lemhiflumine, P. malacaense,P.minnesotense*,P.monsgalena,P.monsserratidens,P. salmoniflumine[* not included inFig. 18, for details on their phylogenetic relationship, seeCrouset al.(2019)].
Extrolites: Red anthraquinones possibly related to roseopurpurin (Peterson et al.2015);P. colei andP. monsserratidens produce cit-reoviridin (Petersonet al.2015).
Series Jiangxiensia Houbraken & Frisvad, ser. nov. MycoBank MB834259.
Etymology: Named after the type species of the series, Penicillium jiangxiense.
Type:Penicillium jiangxienseH.Z. Kong & Z.Q. Liang, Mycosystema 22:
4. 2003.
Diagnosis:Phylogeny: SeriesJiangxiensiabelongs to subgen. Asper-gilloides, sect.Cinnamopurpureaand is sister to the other series of sect.
Cinnamopurpurea.Morphology & physiology: Colonies growing slowly;
sporulation poor, conidial colour en massegrey-green, blueish grey;
conidiophores predominantly monoverticillate, occasionally with an additional branch, stipes smooth; conidia globose to subglobose or ellipsoidal, smooth; growth at 37 °C reported inP.jiangxiense.Sexual morphunknown; sclerotia absent (P.jiangxiense) or present (P. pusil-lum), brownish. Series description based on Smith (1939), Pitt (1980) andKong & Liang (2003).
Included species:Penicillium jiangxiense,P.pusillum.
Extrolites: No chemotaxonomic data available for these species.
SeriesNodulaHoubraken & Frisvad,ser.nov.MycoBank MB834260.
Etymology: Named after the type species of the series, Penicillium nodulum.
Type:Penicillium nodulumH.Z. Kong & Z.T. Qi, Mycosystema 1: 108.
1988.
Diagnosis:Phylogeny: SeriesNodulabelongs to subgen.Aspergilloides, sect.Cinnamopurpureaand is phylogenetically sister to ser.Idahoensia (Fig. 18).Morphology & physiology: Colonies growing restricted; conidial colouren massedull green to olive green (P.nodulum,P. shennong-jianum) or uncoloured (P. incoloratum); conidiophores predominantly monoverticillate, occasionally branched; stipes smooth, short, less than 50 μm in length; conidia globose to subglobose (P. incoloratum, P. shennongjianum) or ellipsoidal (P.nodulum), smooth-walled; growth at 37 °C absent.Sexual morphunknown; sclerotia not produced in culture.
These species are to date only reported from China. Series description based onKong & Qi (1988)andHuang & Qi (1994).
Included species: Penicillium incoloratum, P. nodulum, P. shennongjianum.
Extrolites:Penicillium nodulumproduces griseofulvin, but there are no chemotaxonomic data available for the other species in ser.Nodula.
Notes on series of sect. Cinnamopurpurea: Peterson et al. (2015) studied the species within sect. Cinnamopurpurea. They noted that this group of species are morphologically quite similar, all producing subglobose to ellipsoidal smooth to finely roughened spores, mono-verticillate to divaricate bimono-verticillate smooth-walled conidiophores and quite slow-growing colonies, often with a brown reverse on some media (Petersonet al.2015). It is difficult tofind good characters to delimit series in this section and the current series classification is therefore based on phylogenetic data.
Section Citrina Houbraken & Samson, Stud. Mycol. 70: 40. 2011.
MycoBank MB563132.
Type:Penicillium citrinumThom, U.S.D.A. Bur. Animal Industr. Bull. 118:
61. 1910.
Description: See Houbraken & Samson (2011)andHoubraken et al.
(2011a)(morphology, phylogeny).
SeriesCitrinaRaper & Thom ex Pitt, The Genus Penicillium: 290. 1980 [1979]. MycoBank MB832965.
Synonym:Penicilliumser.ImplicataRaper & Thom ex Pitt, The Genus Penicillium: 191. 1980 [1979].
Type:Penicillium citrinumThom, U.S.D.A. Bur. Animal Industr. Bull. 118:
61. 1910.
Diagnosis:Phylogeny: SeriesCitrinabelongs to subgen.Aspergilloides, sect.Citrina, and the phylogenetic relationship with other series is un-known (Fig. 18).Morphology & physiology: Colonies growing moder-ately or fast; conidial colouren massevariable, (blueish) grey-green, dull green or pure green; conidiophores biverticillate, smooth; conidia globose, subglobose or broadly ellipsoidal, smooth orfinely roughened;
growth at 37 °C variable (absent:P.gorlenkoanum,P.steckii,P. tropi-coides, P.tropicum; variable:P.hetheringtonii,P.sizovae; present:P. citrinum).Sexual morph unknown, or present (P.tropicoides,P. tropi-cum), eupenicillium-type, orange-tan, becoming (brownish) grey; asco-spores ellipsoidal, with two narrow closely appressed equatorial ridges, convex smooth orfinely roughened; sclerotia absent. Series description
growth at 37 °C variable (absent:P.gorlenkoanum,P.steckii,P. tropi-coides, P.tropicum; variable:P.hetheringtonii,P.sizovae; present:P. citrinum).Sexual morph unknown, or present (P.tropicoides,P. tropi-cum), eupenicillium-type, orange-tan, becoming (brownish) grey; asco-spores ellipsoidal, with two narrow closely appressed equatorial ridges, convex smooth orfinely roughened; sclerotia absent. Series description