Peronospora violacea is a floricolous downy mildew which infects plants in the Caprifoliaceae.

It has been reported from hosts in the genera Dipsacus, Knautia, Lomelosia, Scabiosa, and Succisa.

[1] It produces conidiophores on the petals and styles of the host, oospores inside the petal and style tissue, and suppresses the development of the anthers.

Infection is systemic, with hyphae produced in the xylem of the host rhizomes and stems.

[2] In infected plants of Succisa pratensis the flowers have longer, pinker petals on which the conidophores are produced.