The ethnobotanical uses of South American species of Strychnos L. (Loganiaceae) 
are reviewed, with the exception of their major rôle in the preparation of 
curare, which will be dealt with in detail elsewhere. Medicinal uses are less 
common than is the case with the African and Asian species of the genus. About 
140 samples, mostly of leaves, belonging to 53 species, have been screened for 
alkaloids. As with species from other parts of the world, the stem bark and root 
bark tend to be a richer source than leaves. Nor-harman is present in extracts 
from S. barnhartiana leaves. Pyridino-indolo-quinolizidinone (angustine-type) 
bases are also found in several species. The occurrence and pharmacology of the 
(non-curarizing) alkaloids known to be present in South American Strychnos 
species is reviewed.