As part of a study on the biosynthesis of lupanine from 14CO2, an investigation was undertaken of the alkaloids in Lupinus hartwegii using freshly harvested material to (1) determine whether any sparteine was present; (2) confirm lupanine as the major alkaloid; (3) determine the structure of an unknown component (A); and (4) characterize as many other alkaloids as possible. In addition to lupanine (1) and 13-hydroxylupanine originally reported in flowering plants of L. hartwegii, four oxosparteines—aphylline (3), epiaphylline, 13-hydroxyaphylline (virgiline), and 10,17-dioxosparteine— not previously reported in any Lupinus species were isolated. 4-hydroxylupanine (nuttaline), a-isolupanine (6), and gramine (7) were also present, along with five other partially characterized alkaloids. Even though carefully looked for, no sparteines (2,5,8), lupinine, or angustifoline were detected.