Uploaded December 2017 | Updated September 2026, 2 weeks ago
Countdown of the most harmful plant species that you should avoid! Don't touch any of these toxic flowers, trees and bushes
#12.. “White Snakeroot”- The Ageratina altissima [ajehr-uh-teenah all-tee-seema] commonly known as the White Snakeroot or the white sanicle. The plant is an herb native to North America and is most often found in the Midwestern, United States. The White Snakeroot has thin stems and cluster of small white flowers and disperses its seed via the wind. The plant contains a chemical known as tremetol which is a form of toxic alcohol. When enough is ingested tremetol causes fatigue, digestive problems and muscle tremors, which can be fatal if not treated. Because it is frequently found in pastures, cows have been known to accidentally consume the plant which can lead to them producing toxic milk. When this milk is drank it causes an illness colloquially called ‘milk sickness’. In the 1800s, milk sickness became a minor epidemic because it’s herbal cause hadn’t yet been identified and even took the life of Abraham Lincoln’s mother Nancy.
#11. “Rhododendron”- The Rhododendron ponticum or the common Rhododendron is an evergreen shrub that has purple flowers and is a popular bush in landscaping and within the gardening community. It is found all over Europe and parts of central Asia. If the grayanotoxins [gry-an-oh that are found in Rhododendron’s nectar and pollen are consumed it can lower a person’s heart rate to a dangerous level and cause circulatory shock. The main way that humans can fall victim to this poison by eating the honey of a bee that fed off of Rhododendron flowers. The grayanotoxin is also known to cause diarrhea and be a mild hallucinogen. In ancient history it was written that the knowledge of the poisonous effects of Rhododendron honey helped King Mithridates [myth-rih-date-eez] defeat an invading Roman battalion as they invaded the Black Sea Region in 67 B.C. According to the story, the King ordered that honeycombs full of the honey be left along the trails where the Romans would be marching. The Romans gobbled them up becoming inebriated and delirious making them easy prey for the King’s Army. Rhododendron’s are especially poisonous to horses and are on the invasive species list due to its ability to grow in almost any conditions, speedy growth process and dense root system that muscles out other plants.
#10. “Lily of the Valley”- The Convallaria majalis or Lily of the Valley is an white flowering herb from the asparagus family and is the national flower of Finland. The Lily of the valley produces small red berries and its tiny flowers of the are bell-shaped and clustered at the top of the plant. It is naturally found in the Eastern United States and parts of Eurasia, but is also a frequent feature of gardens due to its pleasant aroma and growth traits that make it well-suited for filling empty patches. This delicate looking plant contains upwards of 40 different cardiac glycosides, which if consumed, will cause the sometimes fateful symptoms of migraines, disorientation, vomiting, stroke and cardiac arrest. In small quantities the glycosides can be used for medicinal purposes, but if the raw plant is eaten a hospital trip is mandatory.
Countdown of the most harmful plant species that you should avoid! Don't touch any of these toxic flowers, trees and bushes
#12.. “White Snakeroot”- The Ageratina altissima [ajehr-uh-teenah all-tee-seema] commonly known as the White Snakeroot or the white sanicle. The plant is an herb native to North America and is most often found in the Midwestern, United States. The White Snakeroot has thin stems and cluster of small white flowers and disperses its seed via the wind. The plant contains a chemical known as tremetol which is a form of toxic alcohol. When enough is ingested tremetol causes fatigue, digestive problems and muscle tremors, which can be fatal if not treated. Because it is frequently found in pastures, cows have been known to accidentally consume the plant which can lead to them producing toxic milk. When this milk is drank it causes an illness colloquially called ‘milk sickness’. In the 1800s, milk sickness became a minor epidemic because it’s herbal cause hadn’t yet been identified and even took the life of Abraham Lincoln’s mother Nancy.
#11. “Rhododendron”- The Rhododendron ponticum or the common Rhododendron is an evergreen shrub that has purple flowers and is a popular bush in landscaping and within the gardening community. It is found all over Europe and parts of central Asia. If the grayanotoxins [gry-an-oh that are found in Rhododendron’s nectar and pollen are consumed it can lower a person’s heart rate to a dangerous level and cause circulatory shock. The main way that humans can fall victim to this poison by eating the honey of a bee that fed off of Rhododendron flowers. The grayanotoxin is also known to cause diarrhea and be a mild hallucinogen. In ancient history it was written that the knowledge of the poisonous effects of Rhododendron honey helped King Mithridates [myth-rih-date-eez] defeat an invading Roman battalion as they invaded the Black Sea Region in 67 B.C. According to the story, the King ordered that honeycombs full of the honey be left along the trails where the Romans would be marching. The Romans gobbled them up becoming inebriated and delirious making them easy prey for the King’s Army. Rhododendron’s are especially poisonous to horses and are on the invasive species list due to its ability to grow in almost any conditions, speedy growth process and dense root system that muscles out other plants.
#10. “Lily of the Valley”- The Convallaria majalis or Lily of the Valley is an white flowering herb from the asparagus family and is the national flower of Finland. The Lily of the valley produces small red berries and its tiny flowers of the are bell-shaped and clustered at the top of the plant. It is naturally found in the Eastern United States and parts of Eurasia, but is also a frequent feature of gardens due to its pleasant aroma and growth traits that make it well-suited for filling empty patches. This delicate looking plant contains upwards of 40 different cardiac glycosides, which if consumed, will cause the sometimes fateful symptoms of migraines, disorientation, vomiting, stroke and cardiac arrest. In small quantities the glycosides can be used for medicinal purposes, but if the raw plant is eaten a hospital trip is mandatory.
