Recent research suggests that, in addition to the well-documented occurrence of significant quantities of cocaine and related alkaloids in a limited number of species, the genus Erythroxylon will prove to be a rich source of tropane alkaloids. These bases are esters of a range of acids with tropine, 3 alpha, 6 beta-dihydroxytropane and 3 alpha, 6 beta, 7 beta-trihydroxytropane; the numbers are further increased by nor-derivatives, and stereoisomerism involving the C-3 hydroxyl of the tropane skeleton. The diterpenes of the genus also appear worthy of further study.