Peronospora potentillae. [Descriptions of Fungi and Bacteria].
Abstract A description is provided for Peronospora potentillae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Potentilla argentea, P. aurea subsp. aurea, P. aurea subsp. chrysocraspeda (=P. ternata), P. crantzii, P. pabelliformis, P. gracilis subsp. nuttallii (=P. nuttallii), P. grandiflora, P. nepalensis, P. norvegica, P. norvegica var. hirsuta, P. pulcherrima, P. sterilis. Possibly Fragaria vesca and F. moschata, but see below. DISEASE: Downy mildew of Potentilla species; an obligately necrotrophic plant pathogen. GEOGRAPHICAL DISTRIBUTION: Asia; India, USSR (Uzbekistan). Europe; Czechoslovakia, Denmark, Eire, Finland, France, Germany, Italy, Norway, Poland, Rumania, Sweden, Switzerland, UK (England, Wales, Scotland), USSR (Latvia; RSFSR). North America; USA (Arkansas, Colorado, Idaho, Indiana, Iowa, Kansas, Michigan, New Jersey, Oregon, Texas, Washington State, Wisconsin, Wyoming), Canada (British Columbia, Saskatchewan) TRANSMISSION: By spores ('conidia') dispersed by wind or rain-splash. The role of oospores (if they are usually formed) in disease transmission is unknown.