The peace lily (Spathiphyllum wallisii) is a species of flowering ornamental plant from the Araceae family.Spathiphyllum is a genus of about 47 species of monocotyledonous flowering plants in the family Araceae, native to tropical areas of the Americas and Southeast Asia. Certain species of Spathiphyllum are commonly known as spaths or peace lilies.They are evergreen herbaceous perennial plants with large leaves 12–65 cm long and 3–25 cm wide. The flowers are produced in spadixes, surrounded by 10–30 cm long, white, yellowish, or greenish. Plants do not need much light or water to survive. They are most often grown as houseplants, but they can also withstand the elements well enough to thrive when grown outdoors in hot, humid situations.Peace lilies contain calcium oxalate crystals which are toxic to cats and dogs if ingested.