Peronospora euphorbiae. [Descriptions of Fungi and Bacteria].
Abstract A description is provided for Peronospora euphorbiae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Euphorbia dulcis, E. paralias, E. peploides, E. peplus, E. platyphylla, E. prostrata, E. serpens, E. serpyllifolia, E. serratula (= E. stricta). DISEASE: Downy mildew of Euphorbia species. Leaf lesions are hypophyllous, but superficial in E. paralias, as it has stomata on the upper surface of its leaves, which curl upwards. GEOGRAPHICAL DISTRIBUTION: Africa: South Africa. Asia-Temperate: Japan. Europe: France, Italy, Majorca, Poland, Romania, Spain, Switzerland, UK (England). North America: USA (South Dakota, Texas). TRANSMISSION: By conidia which are dispersed by wind or rain-splash. The role of oospores in disease transmission is unknown, but they may serve as perennating structures.