According to the Guinness Book of World Records, based on the amount of poison it takes to kill a human, the most poisonous common plant in the world is the
1: Oleander
The oleander, or Nerium oleander, is considered by many to be the most poisonous plant in the world. All parts of the beautiful oleander contain poison — several types of poison. Two of the most potent are oleandrin and neriine, known for their powerful effect on the heart.
The deadliest flower in the insect world is a lifeline to farmers—and the planet. The yellow center of the 'killer chrysanthemum' contains a natural toxin that is a powerful insecticide.
Costus longibracteatus 'Kiss of Death'
Deadly Nightshade
The flowers of this plant are small, reddish purple and tubular shaped, but it is the berries that are the most deadly part of the plant. The atropine found in belladonna disrupts the nervous system and can destroy the body's ability to regulate breathing and heart rate, leading to death.
Oleander. Native to Europe and Asia, but planted worldwide in ornamental gardens, oleander is at the top of our list of deadly flowers. It's popular as a backyard plant for good reason. It grows as an evergreen shrub and decorates itself with showy flowers and fruits, not to mention it's extremely hearty.
All parts of azaleas are poisonous for humans and pets. Therefore, while gorgeous in looks, azaleas are deadly flowers containing grayanotoxins. So, ingesting a small quantity of the plant will not likely lead to severe illnesses, but consuming a larger part of the plant correlates with life-threatening conditions.
excelsa. Known colloquially as the gympie gympie (from the Gubbi Gubbi/ Kabi Kabi name for the plant, gimpi gimpi), gympie stinger, and giant stinging tree (D. excelsa), this plant has the dubious honour of being arguably the most painful plant in the world.
These include agapanthus, autumn crocus, clivia, daffodil, hippeastrum, hyacinth, lily of the valley, tulips and some irises. The bright yellow and red seeds are used in bush tucker, but only after the toxins have been leached out. They're poisonous if you eat them fresh from the branch.
The giant hogweed's toxic sap could give you third-degree burns if you don't get out of the sun and wash it off immediately. Like an anti-sunblock, chemicals in its juices disrupt your skin's ability to filter out harmful UV rays.
Cyclamen
This flower symbolizes separation, so not one of the best choices to give your beloved. If they know what this flower means, they might interpret the gift as a sign to get separated from you.
Is Bleeding Heart Toxic? Bleeding heart plants contain isoquinoline alkaloids that are toxic to humans and animals. Serious cases of poisoning are common in dogs and horses, but much less common in humans. The toxins in bleeding heart can cause liver damage and seizures in humans when ingested in large quantities.
The manchineel (aka Hippomane mancinella, aka the Tree of Death) is native to coastal areas in southern North America, such as South Florida, as well as the northern reaches of Central and South America and the Caribbean.
Gelsemium comes in three flowering varieties – two native to North America and one to China. All three can be deadly. The most toxic variety of gelsemium, Gelsemium elegans, only grows in Asia, and is also known as “heartbreak grass”.
The death tree or Manchineel tree is so poisonous, that even Guinness Book of World Records has recorded it to be the most dangerous tree in the world. The poisonous sap oozes out of everything, the bark, leaves and even the fruit.
Poppy. Cheerful poppies have a dark side: they're symbols of sleep and oblivion, and the Chinese flower calendar even calls the poppy a harbinger of evil, signifying the inability to control one's worst urges.
Events in the genome of Welwitschia have given it the ability to survive in an unforgiving desert for thousands of years.
Maybe you need to coat yourself in stinging nettles so powerful that anyone who touches you will immediately vomit and might feel that pain for years. If that last one sounds appealing, you might just be the gympie gympie. No wonder it's nicknamed the "suicide plant."
The corpse flower (Amorphophallus titanum) is the largest unbranched inflorescence in the plant kingdom, boasts a powerful stink, and blooms for just 2-3 days once every year or two. The bloom can grow up to 8 feet tall!
Daffodil (Narcissus)
Daffodils should be given as a symbol of forgiveness, or in appreciation. Even though they're not seen much in the US until spring, the Narcissus, also known as the Daffodil, Jonquil, or Paperwhite, is the flower of December.