Contrayerva

Contrayerva, or contrajerva, is the medicinal rhizome of various tropical Central American and South American species of Dorstenia in the family Moraceae, mainly Dorstenia contrajerva and the closely related Dorstenia drakena but also Dorstenia brasiliensis. The word contrayerva means “counter herb” in Spanish. It was given this name since a 16th-century description (see below) claimed that the leaves of a herb (yerva = hierba) were used by South American Indians to counter the deadly poisonous effect of the same herb (“contra yerva”) when used as an arrow poison. Seventeenth century herbalists and botanists identified this herb as the aromatic root that had been brought from Peru to England by Francis Drake, and claimed that it was an antidote against all kinds of poison. By the late 18th century contrayerva had lost its reputation as an antidote, but it continued to be listed in European and American pharmacopoeias and herbals until the 1920s as a gentle stimulant, tonic and diaphoretic. It is still used in folk medicine in Central and South America.