Phonetic: Pear-on-oh-spore-uh

Peronospora is a widespread obligate parasite of vascular plants, causing diseases called downy mildews. It is commonly found in temperate to warm-temperate areas on leaves, stems, flowers, and fruits and vegetables. All 260 species that are recognized are considered plant pathogens. The spores of Peronospora may be found indoors as a part of the normal influx of outdoor molds. The species P. tabacina is the cause of the Blue-Mold Disease of tobacco. The name refers to the bluish-purple color of the sporangia, which is a feature of many species of Peronospora. Culture - Potato dextrose agar or Malt extract agar, 20° – 25°C, 7 – 10 days.