Contrayerva

In botany, the contrayerva, or contrajerva, is the root and scaly rhizome of various tropical American species of Dorstenia in the family Moraceae (D. contrajerva and D. brasiliensis), a South American plant, the aromatic root of which is sometimes used in medicine as a gentle stimulant and tonic. It was previously used as an antidote to snake bites.

The name is used in Jamaica to refer to a species of Birthwort (Aristolochia odoratissima) still believed to have antidotal properties.

The root is smaller than that of the iris, reddish outside and white inside, knotty, and fibrous. To be of use, it must be new, heavy, and of a dusky red color. Its odor resembles that of fig leaves. Its taste is aromatic, accompanied with some acrimony.

The contrayerva root was formerly considered by many writers to be one of the best anti-epidemics known. Dr. Nathaniel Hodges (1629–1688), in his treatise of the Great Plague of London (Loimologia; published in 1672), had a recipe which he said was very successful, and of which this root was one of the chief ingredients.