Liver necrosis and photosensitisation in cattle after eating Persicaria lapathifolia (pale knotweed) and Persicaria orientalis (Prince's feather).

Cattle deaths in two contemporaneous incidents were attributed to acute intoxication with Persicaria lapathifolia and P. orientalis when the plants were under heat and moisture stress. To our knowledge this is the first confirmed report of acute, fatal hepatic necrosis associated with ingestion of these plants.