332 Persoonia–Volume41,2018

Acaulium pannemaniae

333Fungal Planet description sheets

© 2018 Naturalis Biodiversity Center & Westerdijk Fungal Biodiversity Institute

FungalPlanet827–13December2018

Acaulium pannemaniae Sandoval-Denis,sp. nov. Etymology.NamedafterAminaPanneman,whocollectedthesample.ThisspecieswasdiscoveredduringaCitizenScienceprojectintheNether-lands, ‘Wereldfaam,eenschimmelmet jeeigennaam’,describingnovelfungalspeciesisolatedfromDutchsoils.

Classification—Microascaceae, Microascales, Sordario­mycetes.

ColoniesonOAat25°Cattaining18–24mmin14d,ochreoustobuffcoloured, flat,membranouswithregularmargins.OnPDAat25°Cattaining13–15mmin14d,whitetolightbuff,flat,fluffytodustywithmembranousperipheryandregularmargins.Vegetative hyphaeseptate,hyaline,smooth-andthin-walled.Conidiophores mononematous, penicillate branched; irregularly bi-toterverticillate,bearinggroupsof2–4conidiogenouscells,rarely reduced to single conidiogenous cells borne laterally on theaerialhyphae,hyaline tosubhyaline,smooth-walled.Conidiogenous cells percurrent, lageniform to ampulliform, (11–)13.5–29(–44)× 3–4.5μm,21.4±7.5× 3.9±0.3μmlong, broad at the widest part, tapering to a long cylindrical, annellatedzone,1.5–2.5μmwide,upto23μmlong,annella-tionsinconspicuous.Conidia bullet-shaped or broadly clavate, (5.5–)6.5–10.5(–13)×(2.5–)3–4(–5),8.6±1.7×3.5±0.4μm,withadistinctive truncatebaseand roundedorslightlypointedapex,subhyalinetopalebrowninmass,smooth-orfinelyroughened,thick-walled,arrangedinlongchains.

Typus.the netherLandS,Gelderland,Kapel-Avezaath, fromsoilunderwoodenchippings,2017,A. Panneman(holotypeCBSH-23741,cultureex-typeCBS145025=JW79009;ITS,LSU,tef1 and tubsequencesGenBankLS999990,LS999991,LS999992andLS999993,MycoBankMB827981).

Notes—ThegenusAcaulium was recently reinstated and segregated from Scopulariopsis(Sandoval-Denisetal.2016).Fourspeciesarecurrentlyaccepted(Woudenbergetal.2017).Acaulium pannemaniae closely resembles Acaulium album.However,thenewspeciesdifferbyproducingmononematousconidiophores only in contrast to the synnematous coni dio-phores of A. album.Acaulium pannemamiae also exhibitsmuchlargerconidiogenouscells,oftenwithexceptionallylongannellated necks which also contrast with all other known spe-ciesofthegenus.

Colour illustrations. Background, collection site; branched conidiophores, conidiogenouscellsandconidia.Scalebars=10µm.

MarceloSandoval-Denis,WesterdijkFungalBiodiversityInstitute,P.O.Box85167,3508ADUtrecht,TheNetherlands;FacultyofNaturalandAgriculturalSciences,DepartmentofPlantSciences,UniversityoftheFreeState,

P.O.Box339,Bloemfontein9300,SouthAfrica;e-mail:m.sandoval@westerdijkinstitute.nl