The flowers of Catharanthus roseus (L.) G.Don enjoy the reputation in the folklore of possessing hypoglycemic properties and are, therefore, administered to diabetic patients. While a large amount of work has been carried out on the alkaloidal contents of the leaves of C. roseus (1-6), little work has been done on the flowers of this plant. We report here the isolation of ten alkaloids from its flowers: vinblastine, coronaridine, 11-methoxytabenonine, tetrahydraalstonine, ajmalicine, catharanthine, mitraphylline, vindorosine, vindoline, and a new alkaloid that appears to be isomeric to vincristine. A screening program (1) found several Eriogonum species (Polygonaceae, Buckwheat family) to contain alkaloids. Because this was the first report of alkaloids in the genus Eriogonum, we have identified the major alkaloidal components in four species.