Physoderma alfalfae. [Descriptions of Fungi and Bacteria].
Abstract A description is provided for Physoderma alfalfae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Medicago saliva (Lucerne, alfalfa) and Medicago spp. DISEASE: Crownwart of alfalfa. The disease is first noticeable in spring when the base of plant stems become slightly thickened. This thickening continues until large white warts or galls appear. Most galls reach full development in the summer, then decay rapidly with only a few surviving until the following spring (Jones & Drechsler, 1920; 58, 2281). GEOGRAPHICAL DISTRIBUTION: Asia, Australasia and Oceania, Europe, North America and South America (CMI Map 130, ed. 3, 1973). TRANSMISSION: By dissemination of resting sporangia. Local dispersal by spores swimming in water films may also occur.