Lily of the valley (Convallaria majalis) is a perennial, rhizomatous plant which is often grown as an ornamental but can quickly become a weed. The plant contains at least 38 different cardiac glycosides and saponins.
Ingestion of even small quantities of cardiac glycosides in plant parts can result in progressive decrease in electrical conductivity through the heart causing irregular heart activity and eventually completely blocking cardiac activity. Death usually occurs within 24 hours.
