The name anemone mosaic is proposed for a previously unrecorded virus disease ofAnemone coronariaL.; infected plants have mottled leaves, and broken and distorted flowers. This virus can cause winter browning, and can contribute to crinkle in anemones.The virus infected forty‐seven out of ninety plant species tested; it was transmitted by mechanical inoculation, and by four of the six aphid species tested. Most aphids ceased to be infective within 30 min. when continuing to feed after leaving an infected plant.Propertiesin vitrovaried according to conditions of the tests; the thermal inactivation point was always below 62°C., the dilution end‐point did not exceed 1/2500, and the virus inactivated at 18°C., the fewer than 72 hr.Intracellular inclusion bodies were produced in all hosts examined.Anemone mosaic virus is very similar to viruses placed in the turnip virus 1 group of Hoggan&Johnson, and is serologically related to cabbage black ringspot virus, although AMV infection did not protect plants against infection with cabbage black ring‐spot virus.Weeds naturally infected with AMV were found in anemone plantations, and this virus was detected, together with cucumber mosaic and tobacco necrosis viruses, in corms imported into this