The Strychnine tree (Strychnos nux-vomica) also known as Nux vomica, is an evergreen tree native to southeast Asia, a member of family Loganiaceae. It grows in open habitats, usually attaining a size about 25 meters tall.

It is a major source of the highly poisonous alkaloid strychnine, derived from the seeds inside the tree’s round, green to orange fruit. However, the tree’s bark also contains poisonous compounds, including brucine.

In homeopathy, Nux-v. — as it is commonly abbreviated — is one of the most commonly prescribed remedies.