White Snakeroot, White Sanicle, Tall Boneset



Hazard Information

Route: Ingestion     Plant Part: Indirect Ingestion

Scale: Low

When plant is consumed by cattle, products from that animal (Meat, Milk) is contaminated. If contaminated products are eaten in large enough quantities by humans, this causes trematol poisoning by bioaccumulation.

Common Name(s)


White Snakeroot, White Sanicle, Tall Boneset

Latin Name

Ageratina altissima



Herbaceous perennial plant species of eastern North America



All parts of the plant are poisonous.



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 onto humans, and if consumed in large enough quantities can cause tremetol poisoning in humans.


Flowering Period

July to September.


Native to North America & grows in the wild. Used as medication; may cause liver damage. May also be present in garden centres.