Erysiphe euonymi de Candolle, 1815
on Euonymus

Euonymus europaeus, Belgium, prov. Antwerp, Mol, de Maat © Carina Van Steenwinkel

infected leaf, underside

young cleistothecium

Euonymus europaeus, Belgium, prov. Antwerp, Mol, de Maat © Carina Van Steenwinkel

mycelium and cleistothecia

cleistothecia

appendages
gall
mycelium mainly hypophyllous, thin, persistent. Appressoria more or less lobed, single or paired. Conidia solitary, oblong-elliptic, without fibrosin bodies. Cleistothecia not rare, with 4-8 asci, that contain 3-4 spores. Appendage 5-20, equatorial or somewhat above, 2-7 x the diameter; they are flexuous, slender, aseptate, almost hyaline; apically they are several times loosely and irregularly branched. The appendages have a tendency to point in one direction.
host plants
Celastraceae, monofaag
Euonymus atropurpureus, europaeus, latifolius, verrucosus.
synonyms
Microsphaera euonymi (de Candolle) Saccardo, 1882.
references
Bahçecioğlu & Yildiz (2005a), Brandenburger (1972a), Braun (1995a), Braun & Cook (2012a), Bresinsky (2016a), Czerniawska (2001a), Dietrich (2013a), Doppelbaur & Doppelbaur (1973a), Dynowska, Fiedorowicz & Kubiak (1999a), Heluta, Hayova, Tykhonenko ao (2010a), Jage, Klenke, Kruse ao (2016a), Jage, Klenke & Kummer (2010a), Jage, Kruse, Kummer ao (2013a), Klenke & Scholler (2015a), Korytnianska & Popova (2012a), Kozłowska, Mułenko & Heluta (2015a), Kruse (2014a, 2019a), Leysen (2017a), Mieslerová, Sedlářová, Michutová, ao (2020b), Ruszkiewicz-Michalska (2006a), Ruszkiewicz-Michalska & Michalski (2005a), Scholler, Reinhard & Schubert (1996a), Świderska, Wołczańska, Kozłowska ao (2005a).