dumbcane

dumb +‎ cane, due to its poisoning effect on the throat.

dumbcane (usually uncountable, plural dumbcanes)

1. A tropical plant of the genus Dieffenbachia.
   • 2007 July 17, Jane E. Brody, “Avoiding the Dangers Down in the Garden”, in New York Times‎:

     I was stunned to realize just how many of these potentially dangerous plants were in my own home and garden, including aloe, elephant’s ear, jade, peace lily (Spathiphyllum), philodendron and dumbcane (Dieffenbacchia), as well as foxglove (Digitalis purpurea), hellebore, vinca, rhododendron and chrysanthemum.