peronospora antirrhini peronospora antirrhini peronospora antirrhini is a plant pathogen. it causes downy mildew on leaves of species of antirrhinum and related genera (e.g. misopates). peronospora antirrhini scientific classification kingdom: chromista phylum: oomycota order: peronosporales family: peronosporaceae genus: peronospora species: p. antirrhini binomial name peronospora antirrhinij.schröt. (1874) the disease is generally of minor importance, but can be damaging on antirrhinum seedlings in the glasshouse, which may be systemically infected.