<jats:p>From the seeds of Lupinus multiflorus Lam., a plant growing in north-eastern Argentina, an alkaloid C15H22ON2 has been isolated and named multiflorine. It is identical with the base LV-1 isolated in Australia from the seeds of Lupinus digitatus Forsk. by Crow and Riggs (1955). Most of its reactions and properties are explained by accepting a 2-dehydro-4-oxosparteine structure for the alkaloid.