Phyllactinia orbicularis (Ehrenberg) Braun, 2012
on Fagus, Quercus
Fagus sylvatica, Belgium, prov. Antwerp, Mol © Carina Van Steenwinkel: upperside of an infected lead
same leaf, underside
heavy infection
young and old cleistothecia
cleistothecium
Fagus sylvatica, Belgium, prov. Antwerp, Meerhout, Zeeploop © Carina Van Steenwinkel: fallen leaf
also on the fallen leaf new cleistothecia are formed
gall
mycelium internal and external; the latter hypophyllous, white, persistent, conspicuous in fallen autumn leaves. Appressoria nipple- to rod-shaped, mostly single. Conidia single, clavate, without fibrosin bodies. Conidiophores erect, filiform. Cleistothecia hypophyllous with an equatorial circle of 4-18 stiff, acicular appendages that are abruptly swollen at their base, 1-2 as long as the diameter of the cleistothecium; their tips are blunt or even somewhat thickened. Asci 15-35, 2-spored.
host plants
Fagaceae, oligophagous
Fagus orientalis, sylvatica, x taurica; Quercus faginea, ilex, macranthera, petraea, robur.
references
Braun & Cook (2012a), Bresinsky (2016a), Czerniawska (2001a), Jage, Klenke, Kruse ao (2016a), Klenke & Scholler (2015a), Kozłowska, Mułenko & Heluta (2015a), Kruse (2014a, 2019a), Leysen (2013a, 2017a), Mieslerová, Sedlářová, Michutová, ao (2020b), Tóth (1994a).