Erysiphe divaricata (Wallroth) Schlechtendal, 1824
on Frangula
Frangula alnus, France, dép. Ardennes, Signy-le-Petit © Sébastien Carbonnelle
Frangula alnus, België, prov. Limburg, Kwaadmechelen © Carina Van Steenwinkel: upperside of an infected leaf
underside of an infected leaf
detail
cleistothecium
apex of an appendage
gall
mycelium amphigenous, thin, whitish. Appressoria lobed. Conidia solitary, without fibrosin bodies, elliptic. Foot-cell of conidiophore mostly straight. Cleistothecia with 3-7 asci, containing 3-6 spores. Appendages 4-12, equatorial, 3-7 the diameter; especially the shorter ones stiff, they are flaccid, (almost) entirely hyaline, 0-3 septate; at the tip they are bifurcated 2-4 times in quick succession.
host plants
Rhamnaceae, oligophagous
Frangula alnus; Rhamnus caroliniana.
synonyms
Microsphaera divaricata (Wallroth) Léveillé, 1851.
references
Braun (1995a), Braun & Cook (2012a), Bresinsky (2016a), Doppelbaur & Doppelbaur (1973a), Jage, Scholler & Klenke (2010a), Klenke & Scholler (2015a), Kozłowska, Mułenko & Heluta (2015a), Kruse (2019a), Leysen (2017a), Mieslerová, Sedlářová, Michutová, ao (2020b), Ruszkiewicz-Michalska (2006a), Ruszkiewicz-Michalska & Michalski (2005a), Scholler & Schubert (1993a).