Bitterwood, the heartwood of Picrasma excelsa (Picraena excelsa), known as Jamaica quassia, or of Quassia amara (family Simaroubaceae), known as Surinam quassia; a bitter tonic; the infusion has been administered by enema in the treatment of threadworms. [Quassi, a resident of Surinam who used it as a tonic]
