What Flowers Are Poisonous?

For years, many claimed the popular flowering Christmas plant, the poinsettia, was extremely poisonous and a danger to pets and small children. Yet today, new research indicates this may not be true. While the poinsettia may not be a threat, there are many poisonous flowers which are both beautiful and lethal.


The oleander grows in warmer regions, such as parts of California, Arizona, Texas and Florida. Although the oleander is a common flowering bush often used as a decorative hedge, its flower, as well as all other parts of the plant, is poisonous. Ingestion of the oleander plant results in vomiting, diarrhea, headache, serious heart problems, and even death. A drought-resistant bush, the oleander might be pruned to resemble a tree or grown in a row with other oleanders to create a colorful privacy screen. Oleander flowers come in yellow, white, red, orange and pink. Aside from being poisonous, in many other ways the oleander is an ideal plant--it tolerates poor soil conditions, grows quickly, produces minimal litter and does not attract wildlife to its fruit. The oleander blossom produces a pleasant odor and the plant flowers year-round.


The colorful and woody rhododendron or azalea, a common houseplant and ornamental flowering garden shrub, has a dark side. Do not get too cozy with this lovely but lethal flowering plant, as all of its parts are poisonous. Once ingested, symptoms include watering of the eyes and nose, salivation, stomach pain and nausea, vomiting and diarrhea, depression and difficulty breathing. As the symptoms progress, eventual limb paralysis and coma may occur. Gardening centers and grocery stores commonly sell potted azaleas or rhododendrons. When used as houseplants, keep them away from pets and children.


The periwinkle, or vinca, is an innocent-looking plant with cheerful and brightly colored five-lobed flowers. A hearty, low-growing, drought resistant plant, the vinca does well in desert climates, effortlessly producing an abundance of colorful flowers. In spite of its seemingly mild disposition, all parts of the periwinkle plant are poisonous. The plant is severely toxic to pets, and ingestion can result in vomiting, diarrhea, tremors and eventual death. Often used as a ground cover, the periwinkle comes in a variety of colors, including red, pink, purple and white, and blooms from spring to fall.

Keywords: poisonous, poisonous flowering plants, poisonous flowers

About this Author

Ann Johnson has been a freelance writer since 1995. She previously served as the editor of a community magazine in Southern California and was also an active real estate agent, specializing in commercial and residential properties. She has a Bachelor of Arts in communications from California State University of Fullerton.