Erysiphe russellii (Clinton) Braun & Takamatsu, 2000

on Averrhoa, Oxalis

Oxalis stricta, Belgium, prov. Antwerp, Herselt, Langdonken, 7.ix.2020 © Carina Van Steenwinkel

infected leaf

same leaf, underside

also the fruiting peduncle is affected

conidiophores

conidium

cleistothecium with appendage and extruded asci

asci

ascus

detail of the appendages

only in a minority the appendages were terminally branched

gall

mycelium amphigenous, sometimes also in the inflorescence. Appressoria more or less lobed, single or paired. Conidia solitary, elliptic, without fibrosin bodies. Cleistothecia with 4-10 asci, that contain 3-5 spores. Appendage 5-15, attached to the equator, 2-7 times the diameter; they are septate, brown, flexuous, near the tip 1-4 x times loosely dichotomously branched.

host plants

Oxalidaceae, oligophagous

Averrhoa carambola; Oxalis corniculata, dillenii, fontana, rosea, stricta.

synonyms

Microsphaera russellii Clinton, 1874.

references

Beenken & Senn-Irlet (2016a), Braun (1995a), Braun & Cook (2012a), Bresinsky (2016a), Czerniawska (2001a), Jage, Klenke & Kummer (2010a), Klenke & Scholler (1995a), Kozłowska, Mułenko & Heluta (2015a), Leysen (2017a), Negrean & Anastasiu (2006a), Ruszkiewicz-Michalska (2006a), Ruszkiewicz-Michalska & Michalski (2005a).