Cerastium fontanum subp. vulgare, Belgium, prov. Limburg, Heusden-Zolder © Carina Van Steenwinkel

infected shoot

hypophyllous oown

conidiophore

detail

conidia 19 x 26 µm

gall

upperside of the leaves with paled, slightly embossed patches; at the corresponding underside a greyish fungal bloom, consisting of erect, distally strongly branched conidiophores. The conidia measure 17-21 x 22-30 µm.

host plants

Caryophyllaceae, narrowly monofaag

Cerastium alpinum, arvense & subsp. glandulosum, fontanum & subsp. vulgare, nigrescens, tomentosum.

synonyms

Peronospora trivialis Gäumann, 1923.

notes

Klenke & Scholler describe the colour of the down as “whitish to pale yellowish”; Brandenburger writes “pale yellowish”; that is not in accordance with the picture above. Because the colour of the down is determined by the colour of the conidia, such a difference is not unimportant. Yet, no other identification was feasible.

references

Belbahri, Calmin, Pawlowski & Lefort (2005a), Brandenburger (1985a: 99), Buhr (1964b), Cunnington (2008a), Doppelbaur, Huber & Poelt (1965a), Ellis & Ellis (1997a), García-Blázquez, Constantinescu, Tellería & Martín (2007a), Göker, Voglmayr, Riethmüller ao (2003a), Gustavsson (1991a), Hagen (1941a), Jage, Klenke, Kruse ao (2017a), Klenke & Scholler (2015a), Kruse (2019a), Kozłowska, Mułenko & Heluta (2015a), Kruse (2014a), Müller (2015a), Mułenko, Kozłowska, Bacigálová ao (2014a), Mułenko, Sałata & Wołczańska (1995a), Negrean (1996b), Redfern & Shirley (2011a), Riethmüller, Voglmayr, Göker ao (2002a), Ruszkiewicz-Michalska (2006a), Ruszkiewicz-Michalska & Michalski (2005a), Săvulescu (1948a), Voglmayr (2003a).