Dieffenbachia or Dumb Cane Plants, native to the tropics of Mexico and all the way south to Argentina, are relatively easy-care houseplants with large, broad, patterned, oblong leaves. They can be small table plants or 5ft-6ft. trees depending on the variety you select. Dieffenbachias are fast-growing houseplants that tend to get top heavy if not properly pruned. All parts of a Dieffenbachia are extremely poisonous which is how they earned the nickname “dumb cane plant.” The sap of the Dieffenbachia plant is so toxic, that if ingested, it can cause a temporary inability to speak. Be sure to keep these poisonous houseplants out of the reach of small pets and children.