Dieffenbachia is a genus of tropical flowering plants in the family Araceae. It is native to the New World Tropics from Mexico and the West Indies south to Argentina. It is widely cultivated as an ornamental, especially as a house plant, and has become naturalized on a few tropical islands.

Dieffenbachia is a perennial herbaceous plant with straight stem, simple and alternate leaves containing white spots and flecks, making it attractive as indoor foliage. Species in this genus are popular as houseplants because of their tolerance of shade.

The common name, "dumb canes" refers to the poisoning effect of raphides, which can cause temporary inability to speak; for this reason it is also known as the mother-in-law plant.

Dieffenbachia was named by Heinrich Wilhelm Schott, director of the Botanical Gardens in Vienna to honor his head gardener Joseph Dieffenbach (1796–1863).