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.

hostplants

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 & Kummer (2013a), Voglmayr (2003a).