Erysiphe viburni Duby, 1830

on Viburnum

gall

mycelium amphigenous, at the upper side of the leaf more or less persistent. Appressoria lobed or multilobed, paired or single. Conidia solitary, elliptic, without fibrosin bodies. Cleistothecia 75-130 µm, with 2-8 asci containing 4-8 spores. Appendages 4-22, equatorial, 1-1.5 x the diameter; they are stiff, extending, brown at the base, have 0-2 basal septa, the cell wall is rough; apically they are ± 4-5 times bifurcated in quick succession.

According to Klenke & Scholler conidia are formed only sparingly, and the cleistothecia are hypophyllous.

hostplants

Adoxaceae, monophagous

Viburnum acerifolium, opulus, trilobum.

synonyms

Microsphaera sparsa Howe, 1872; ? Golovinomyces sparsus auct. nec (Braun) Heluta, 1988.

references

Braun (1995a), Braun & Cook (2012a), Bresinsky (2016a), Jage, Klenke, Kruse ao (2016a), Jage, Klenke & Kummer (2010a), Jage, Kruse, Kummer ao (2013a), Klenke & Scholler (2015a), Kozłowska, Mułenko & Heluta (2015a), Kruse (2014a), Scholler & Schubert (1993a).

mod 25.viii.2018