Peronospora stigmaticola Raunkiaer, 1892

on Mentha, Satureja

Peronospora stigmaticola on Mentha spec.

Mentha spec., Belgium, prov. Limbourg, Wellen, Herkvallei, 23.viii.2018 © Carina Van Steenwinkel

Peronospora stigmaticola on Mentha spec.

the fungus appears on browned flowers

Peronospora stigmaticola on Mentha spec.

stigmata with conidiophores

Peronospora stigmaticola on Mentha spec.

detail

Peronospora stigmaticola: conidiophore

conidiophore

Peronospora stigmaticola: conidiophore

terminal branchings of the conidiophores

Peronospora stigmaticola: conidia

conidia

Peronospora stigmaticola: 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).

mod 2.ix.2018