Top 10 Poisonous Plants

Ageratina altissima -- white snakeroot

Ageratina altissima — white snakeroot

“Pet poisonous” – Toxic to Dogs

Ageratina altissima, also known as white snakeroot, richweed, or white sanicle, is a poisonous perennial herb in the family Asteraceae, native to eastern and central North America.

White snakeroot contains the toxin tremetol; when the plants are consumed by cattle, the meat and milk become contaminated with the toxin. When milk or meat containing the toxin is consumed, the poison is passed on to humans. If consumed in large enough quantities, it can cause tremetol poisoning in humans.

The poisoning is also called milk sickness, as humans often ingested the toxin by drinking the milk of cows that had eaten snakeroot. Although 80% of the plant’s toxin, tremetone, decreases after being dried and stored away for 5 years, its toxicity properties remain the same.