Six alkaloids were isolated from the endemic Hawaiian shrub Platydesma campanulata Mann: the known furoquinolines evolitrine and kokusaginine and the new 6-methoxydictamnine (Ia); a new dihydrodictamnine named platydesmine (III); and two derivatives of 4-quinolone. One of these, 1,2-dimethyl-4-quinolone was known heretofore as a synthetic product. The other, pilokeanine, could not be isolated in crystalline form. On the basis of physical and chemical evidence tentative structure V is proposed. © 1963.