Peronospora stigmaticola Raunkiaer, 1892
on Mentha, Satureja
Mentha spec., Belgium, prov. Limbourg, Wellen, Herkvallei, 23.viii.2018 © Carina Van Steenwinkel
the fungus appears on browned flowers
stigmata with conidiophores
detail
conidiophore
terminal branchings of the conidiophores
conidia
conidia
gall
inconspicuous greyish fungal down on the stigma and stylus, consisting of vertical conidiophores that apically several times are dichotomously branching, each branch ending upon an elliptic conidium.
host plants
Lamiaceae, oligophagous
Mentha aquatica, arvensis, x gentilis, longifolia, x pipirita, x rotundifolia, spicata, x verticillata, x villosa; Satureja hortensis.
notes
The fungus is systemic. Contrary to what is usual in the genus Peronospora, the conidia do not fall off spontaneously. Probably this implies that the fungus depend on flower visiting insects for its dispersal.
references
Belbahri, Calmin, Pawlowski & Lefort (2005a), Brandenburger (1985a), Buhr (1964b), Choi, Shin & Thines (2009a), Göker, García-Blázquez, Voglmayr ao (2009a), Jage, Klenke, Kruse ao (2017a), Jage, Kruse, Kummer ao (2013a), Klenke & Scholler (2015a), Săvulescu (1948a), Teppner (1978a), Thines & Choi (2016a), Thines & Kummer (2013a), Voglmayr (2003a).