Hyaloperonospora rorippae-islandicae (Gäumann) Göker, Voglmayr & Oberwinkler, 2009
on Rorippa

Rorippa palustris, Belgium, prov. Flemish Brabant, Deurne (bij Diest), Vallei van de drie beken, Schutshaag, 2.vii.2019 © Carina Van Steenwinkel

same leaf, underside

infection also on the stem

crown of the conidiophore

conidium
gall
upperside of the leaf with pale spots, margin often downfolded; plant sometimes totally disfigured. Underside of the leaves with a greyish down of 0.7 mm high erect conidiophores that apically several times are dichotomously branching, each tip bearing an ovoid conidium.
host plants
Brassicaceae, monophagous
Rorippa amphibia, austriaca, islandica, palustris, sylvestris.
synonyms
Peronospora rorippae-islandicae Gäumann, 1918.
references
Brandenburger (1985a), Buhr (1965a), Doppelbaur & Doppelbaur (1974a), Gustavsson (1991a), Jage, Klenke, Kruse ao (2017a), Klenke & Scholler (2015a), Săvulescu (1948a), Tomasi (2014a).