Phloeospora ulmi (Fries) Wallroth, 1833
on Ulmus
Ulmus laevis, Hungary, Mosonmagyaróvár, 8.ix.2017 © László Érsek
same leaf, underside
upper surface leaf spots
detail
underside
detail

Ulmus x hollandica, Wouwsche Plantage: underside and upper side. The white spots at the underside of the leaf are conidial masses (perhaps a bit washed out by the rain of the day before).

Ulmus spec., Belgium, prov. Flemish Brabant, Diest, Wallen © Carina Van Steenwinkel

extruded conidia mass

conidia
host plants
Ulmaceae, monophagous
Ulmus glabra, x hollandica, laevis.
synonyms
Mycosphaerella ulmi Klebahn, 1902; Septoria ulmi Fries, 1819.
references
Brandenburger (1985a: 69), Dietrich (2016b), Ellis & Ellis (1997), Jage, Klenke, Kruse ao (2016a), Jage, Kruse, Kummer ao (2013a), Jage, Scholler & Klenke (2010a), Kruse (2014a), Quaedvlieg, Verkley, Shin ao (2013a), Scheuer & Bechter (2012a), Selçuk & Hüseyin (2000a).