Quercus robur, Nieuwendam: cleistothecium

detail

detail

Quercus robur, Belgium, prov. Antwerp, Mol, Klein Verkallen © Carina Van Steenwinkel

same leaf, underside

cleistothecium

appendages

asci

notes

mycelium inconspicuous, thin, mainly hypophyllous. Conidia formed sparingly, sometimes missing, solitary, cylindric, with rounded tips, without fibrosin bodies. Cleistothecia mainly hypophyllous, with 4-16 asci that contain 6-8 spores. Generally 10-10 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 bifurcating there several times in quick succession.

host plants

Fagaceae, monophagous

Quercus frainetto, petraea, pubescens, robur & subsp. pedunculiflora.

synonyms

Microsphaera hypophylla Nevodovsky, 1952.

notes

The cleistothecia cannot be distinguished from those of E. alphitoides that also lives on oaks. Contrary to that species, the leaves are not disfigured. Like alphitoides a neophyte, that arrived in Europe around the middle of the 20th century.

references

Braun (1995a), Braun & Cook (2102a), Braun, Cunnington, Brielmaier-Liebetanz, Ale-Agha & Heluta (2003a), Bresinsky (2016a), Dynowska, Fiedorowicz & Kubiak (1999a), Klenke & Scholler (2015a), Kozłowska, Mułenko & Heluta (2015a), Kruse (2014a, 2019a), Leysen (2017a), Ruszkiewicz-Michalska (2006a), Ruszkiewicz-Michalska & Michalski (2005a), Sucharzewska (2009a), Sucharzewska, Dynowska, Kubiak ao (2012b), Talgø, Sundheim, Gjærum ao (2010a).