Peumus boldus, commonly known as boldo, is a species of tree in the family Monimiaceae and the only species in the genus Peumus. It is endemic to the central region of Chile, between 33° and 40° southern latitude. Boldo has also been introduced to Europe and North Africa, though it is not often seen outside botanical gardens.

Ascaridole is a natural organic compound classified as a bicyclic monoterpenoid that has an unusual bridging peroxide functional group. It is a colorless liquid with a pungent smell and taste that is soluble in most organic solvents. Like other low molecular weight organic peroxides, it is unstable and prone to rapid decomposition when heated or treated with organic acids. Ascaridole determines the specific flavor of the Chilean tree boldo and is a major constituent of the oil of Mexican tea (wormseed). It is a component of natural medicine, tonic drinks and food flavoring in Latin American cuisine. As part of the oil, ascaridole is used as an anthelmintic drug that expels parasitic worms from plants, domestic animals and the human body.