Quercus robur, Zwanenwater

notes

mycelium conspicuous, mainly epiphyllous, on often disfigured young leaves. Appressoria lobed, sometimes nipple-shaped or multilobed, solitary or paired. Conidia solitary, barrel-shaped, without fibrosin bodies. Cleistothecia mainly epiphyllous, with 4-16 asci that contain 6-8 spores. Generally 10-20 appendages, attached to the equator. They are up to 2 x as long as the diameter, stiff, hyaline, septate, more or less straight; at the tip they are suddenly broadened because they are bifurcated several times in quick succession.

host plants

Fagaceae, monophagous

Quercus canariensis, castaneifolia, cerris, dalechampii, faginea, frainetto, x hispanica, macanthera, petraea & subsp. iberica, pubescens, pyrenaica, robur, x rosacea, rubra, x streimii.

Rarely on Aesculus hippocastanum; Castanea sativa; Cotinus coggygria; Fagus sylvatica. Observed in Switzerland on Ailanthus altssima (Simaroubiaceae) (Beenken & Senn-Irlet) and Wisteria sinensis (Fabaceae) (Bolay ea).

synonyms

Microsphaera alphitoides Griffon & Maublanc, 1912; Oidium quercinum von Thümen, 1878.

Microsphaera gorlenki Fan Tyk Chen, 1975, described from Daphne, possibly concerned a cleistothecium of alphitoides that has been blown by the wind.

hyperparasites

Ampelomyces quisqualis.

notes

During wet and cool summers especially the young foliage of the lammas shoot can be heavily infested. Arrived in Europe around the beginning of the 20th century; the origin is not known. Considered as one of the causative agents of the decline of the oaks in Europe.

references

Abras, Fassotte, Chandelier & Cavelier (2008a), Bahçecioğlu, Kabaktepe & Yildiz (2006a), Beenken & Senn-Irlet (2016a), Blumer (1967), Bolay, Clerc, Braun, ao (2021a), Brandenburger (1972a, 1985a: 62, 387), Braun (1995a), Braun & Cook (2102a), Braggion (2013a), Bresinsky (2016a), Czerniawska (2001a), Czerniawska, Madej, Adamska ao (2000a), Doppelbaur (1973a), Dynowska, Fiedorowicz & Kubiak (1999a), Ellis & Ellis (1997a), Jage, Klenke, Kruse ao (2016a), Jage, Klenke & Kummer (2010a), Jage, Kruse, Kummer ao (2013a), Jage, Scholler & Klenke (2010a), Klenke & Scholler (2015a), Korytnianska & Popova (2012a), Kozłowska, Mułenko & Heluta (2015a), Kruse (2014a, 2019a), Leysen (2017a), Mayor (1967a, 1975a), Mieslerová, Sedlářová, Michutová, ao (2020b), Mułenko, Piątek, Wołczańska ao (2010a), Ruszkiewicz-Michalska (2006a), Ruszkiewicz-Michalska, Bałazy, Chełkowski, ao (2015a), Ruszkiewicz-Michalska & Michalski (2005a), Scheuer & Bechter (2012a), Scholler, Reinhard & Schubert (1996a), Sucharzewska (2009a), Sucharzewska, Dynowska, Kubiak ao (2012b), Talgø, Sundheim, Gjærum ao (2010a), Tóth (1994a), Unamuno (1943a).